The notion that ADHD constitutes a heterogeneous disorder is well accepted. However, this study contributes with new important knowledge by examining independent effects of a large range of neuropsychological deficits. In addition, the study investigated whether deficits in emotional functioning constitute a dissociable component of ADHD.n = 102; 7–13 years) and a control sample individually matched with regard to age and gender. The administered tasks were designed to tap into three different neuropsychological domains: executive functions , delay aversion, and reaction time variability. Parent ratings of emotion regulation and a test of emotion recognition were also included.The study included children with ADHD (Children with ADHD differed significantly from controls on all measures, except for delay aversion and recognition of disgust. No main effects of gender or interaction effects of gender and group were found. More importantly, executive functioning, reaction time variability, and emotional functioning all contributed independently to distinguishing between children with ADHD and controls.The current study supports the view of ADHD as a heterogeneous disorder related to multiple neuropsychological deficits. In addition, emotional functioning appears to be an area of importance for ADHD that needs to be incorporated into future theoretical models. Recent theoretical models have emphasized the neuropsychological heterogeneity in Attention-deficit/Hyperactivity Disorder ADHD; . DespiteA third factor that has been shown to be strongly related to ADHD is reaction time (RT) variability e.g., . HoweverIn addition to executive functioning, delay aversion, and RT variability, the importance of considering the role of emotional functioning in ADHD has been acknowledged e.g., . CompareThe aim of this study was to examine possible independent effects of a range of different neuropsychological deficits in ADHD, and to investigate whether deficits in emotional functioning constitute a dissociable component of ADHD. As most previous studies have failed to investigate gender differences, we also aimed to explore this issue. Multiple analytic approaches were used. First, simple group differences were studied and a logistic regression analysis was thereafter used to investigate independent effects of different neuropsychological and emotional functions. Next, we followed the suggestion made by, for example, Nigg et al. (2005), who emphasized the need for more person-centered (rather than variable-centered) research in ADHD samples. This was accomplished by categorizing children as “impaired” versus “unimpaired” with regard to neuropsychological and emotional functioning and illustrating the overlap using Venn diagrams .On the basis of the results from the previous studies described above, we made the following hypotheses. First, we hypothesized that children diagnosed with ADHD would perform more poorly compared to controls on tests measuring executive functioning , RT variability as well as delay aversion. Moreover, we hypothesized that these neuropsychological deficits would not fully overlap, but display independent contributions when studied simultaneously. Finally, we hypothesized that children with ADHD would perform more poorly than controls with regard to emotion regulation and emotion recognition. Due to the scarcity of previous studies examining the link between neuropsychological and emotional functioning, no a priori hypotheses were made with regard to this issue. In line with a recent review , we hypoThis study included 102 children (56 girls) aged 7–13 years and diagnosed with ADHD and a control group of 102 children individually matched to the clinical group with regard to gender and age (±6 months). The ADHD sample included clinically referred children who were recruited from Stockholm ADHD center and child and adolescent psychiatric clinics. As one aim was to study gender differences, girls were oversampled. All children had been formally diagnosed with ADHD by a psychiatrist, and the children’s diagnostic status was also confirmed at the time of the study using the ADHD Rating Scale IV , which i2 ≤ .61, ns, parental age, both ts ≤ 1.64, ns, number of siblings, t = .47, ns, nonverbal intelligence, t = 1.37, ns, and birth country of the parents or the child, all χ2 ≤ 2.49, ns.The control group was recruited by contacting schools in the Stockholm-Uppsala area in Sweden. Schools were chosen so that families of different socioeconomic status would be represented. The exclusion criteria for the control group were: (a) severe psychiatric or somatic problems as reported by parents and (b) scores above the 75th percentile on either the inattention or the hyperactivity subscale on the ADHD Rating Scale IV  as measured by teachers or parents. Controls and children with ADHD did not differ significantly with regard to parental education, both χThe study was approved by the ethics committee at the Karolinska Institute, Stockholm, Sweden.The tests were chosen based on previous research identifying three major aspects of executive functioning: working memory, inhibition, and shifting e.g., . All meap < .001).Working memory was measured using three tasks: one spatial and two verbal. Spatial working memory was measured using the ‘Find the phone task,’ which is similar in design to the spatial working memory task included in the Cambridge Neuropsychological Test Automated Battery CANTAB; . In our p < .001).Inhibition was measured using two tasks. The first task was the go/no-go task developed by Shifting was measured using the Navon-like task (see description above). A third trial was performed in which participants had to shift between responding to the local or the global stimuli. A square and a circle in the lower corners of the computer screen indicated what stimulus to respond to . In line with recommendations by Delay aversion was measured using the Choice Delay Task . Particir = .36–.65, p < .001).Reaction time variability was measured as the standard deviation of participants’ reaction time for correct answers on the two nonshifting trials in the Navon-like task and correct answers on the go/no-go task (see descriptions above). Individual scores were standardized and aggregated into one composite score  using the Emotion Questionnaire developed by Rydell et al. (2003). It includes statements related to regulation of anger, fear, sadness, and happiness/exuberance. For each emotion, one general question is asked  and two questions regarding regulation in specific situations . Ratings are made on a scale ranging from 1  to 5 (fully agree), with higher values indicating greater problems with emotion regulation. This instrument has been shown to have high test-retest reliability and high construct validity . Six ADHD children had missing data as their parents did not consent to completing the rating scale.http://www.macbrain.org/resources.htm), which consists of naturally posed photographs  of 43 professional actors . In this study, the children were shown 36 faces displaying six different emotions: anger, fear, sadness, happiness, surprise, and disgust. One ADHD child had missing data. The score used was number of correct responses (maximum score = 6).Emotion recognition was measured using facial images selected from the NimStim Set of Facial Expressions  boys were significantly older than girls, t = 3.16, p < .001. For the remaining analyses, age was not controlled for, as the groups (ADHD and controls) were matched with regard to this variable. However, to address the question of whether group differences were equally large across the age span studied, we divided the sample into three equally large age groups and investigated interactions of group (ADHD vs. controls) and age group. As the pattern of results was found to be similar for all three age groups, these findings are not further described in the results section below. Gender was used as a separate factor in the ANCOVAs, as one aim of the study was to examine main effects of gender and interaction effects of group and gender. For the other control variables, the results were first presented without control for intelligence, internalizing problems, and conduct problems. However, the analyses were thereafter rerun including these covariates and changes in the results are reported. Univariate outliers were defined as children within each group (ADHD vs. controls) with a value above or below 3 SD. Outliers were handled by replacing the extreme value with the value at 3 SD. This procedure eliminated the impact of outliers and allowed us to retain all children in the analyses.Age was used as a covariate in the correlations and in the ANCOVAs, as (a) all neuropsychological variables except delay aversion were significantly related to age, rs > .24, Correlation analyses showed that the three measures of executive functioning were significantly interrelated, and RT variability was related to all three measures of executive functioning see . Further2 = .09–.27) for the neuropsychological measures, large (η2 = .22–.44) for emotion regulation, and medium to large (η2 = .05–.15) for emotion recognition. No main effects of gender and no significant interactions of group and gender were found. All group differences remained significant when controlling for multiple comparisons . In addition, all group differences remained significant when controlling for either IQ, conduct problems, or internalizing problems, except for recognition of sadness, which did not remain significant when controlling for internalizing problems.When studying group differences, the children with ADHD performed more poorly than controls with regard to all neuropsychological functions except delay aversion see . Moreovep < .001, and a near significant effect of inhibition, Wald = 3.80, p = .05, but no significant effects of shifting and working memory, Walds < 1.81, ps > .18. In the second step, there were significant effects of anger recognition, Wald = 6.08, p < .05, regulation of anger, Wald = 19.60, p < .001, and regulation of happiness, Wald = 4.49, p < .05. The model successfully predicted 64.9% of the ADHD cases  and 84.3% of the controls  after the first step and 91.5% of the ADHD cases and 87.3% of the controls after the second step.Next, a logistic regression analysis was performed, including the variables for which a significant group difference had been found. In the first step, there was a significant effect of RT variability, Wald = 27.09, 2 < 3.36, p = .07. However, for the remaining variables, the results were identical to the ANCOVAs, with ‘impairment’ being significantly more common among children with ADHD compared to controls for all variables except delay aversion and recognition of disgust; all significant χ2 > 18.97, p < .001. Also in line with the ANCOVAs, no significant gender differences were found  and the following analyses will therefore not be presented separately for boys and girls.Thereafter, categorical analyses were conducted by defining impairment as performing poorer than the 90th percentile of the children in the control group. RT variability was the most common neuropsychological impairment and anger regulation the most common emotional impairment see . Chi-squNext, we investigated the overlap between impairments in neuropsychological and emotional functioning see . To be cIn line with current theoretical models of heterogeneity in ADHD , this study aimed to explore independent effects of different neuropsychological functions in ADHD and to investigate whether deficits in emotional functioning might constitute a dissociable component of ADHD. The results showed that the children with ADHD performed more poorly than controls on all variables except delay aversion and recognition of disgust. For the neuropsychological variables, independent effects were only seen for RT variability and inhibition. Furthermore, emotion regulation and emotion recognition showed independent effects beyond the influence of neuropsychological deficits and improved our ability to successfully distinguish between ADHD cases and controls. No significant gender differences were found.In line with a large number of previous studies, this study found that children with ADHD performed more poorly than their typically developing peers on measures of executive functioning  contributed significantly to discriminating between children with ADHD and controls, over and above the influence of neuropsychological functioning. In addition, the categorical analyses showed that a substantial subgroup of children with ADHD (24%) was affected with regard to emotional, but not neuropsychological, functioning.A third important contribution of this study was the result showing that regulation of both positive and negative emotions contributed independently to the prediction of ADHD status. The effect of anger regulation is not surprising considering that comorbid aggression is common in children with ADHD. With regard to happiness/exuberance, our findings are in line with previous studies using the same rating scale, which have found a relation between regulation of happiness/exuberance and externalizing behavior problems in a nonclinical sample using either parent ratings  or self-ratings . More imFinally, it should be noted that when reanalyzing data from several studies, Nigg et al. (2005) showed that about 60%–70% of their sample was categorized as impaired when measures of inhibition and delay aversion were included. Neither this study nor previous studies  have beeThis study had the advantage of including ADHD children and controls of both genders so that boys and girls with ADHD could be compared with one another as well as with same-sex controls. No main effects of gender and no interaction effects of group and gender were found. This is in line with a review by The findings presented here must be addressed within the limitations of the study. First, no standardized clinical interview was used. However, all children were diagnosed by a licensed child psychiatrist and all diagnoses were confirmed using teacher and parent ratings on a standardized rating instrument. In addition, the children’s symptoms were reported to cause significant impairment in several settings and both the duration and age-of-onset criteria were met. A second limitation was that the delay aversion was assessed using only one task, which may have contributed to the low rates of impairment. Future studies should preferably use several tasks to measure both delay aversion and related constructs so as to obtain a clearer picture of motivationally based deficits in ADHD. Third, emotion regulation was assessed using ratings, and it is possible that ratings reflect a generalized parental view of the child as problematic rather than the specific ability to self-regulate. Speaking against this interpretation is the fact that our rating measure has been validated in relation to children’s self-reports  and only moderate relations have been found between emotion regulation and emotional intensity .With regard to future directions, the role of neuropsychological functions in providing valid information for diagnosis should be discussed. Looking at the discriminatory ability in this study, we can conclude that the classification rate was too low to regard deficits in neuropsychological functions as a viable replacement for the behavioral symptoms assessed in the current version of the DSM. Adding measures of emotional functioning improved the classification rate substantially. However, it is for future research to examine the role of emotional deficits in discriminating between different clinical groups. In addition, the role of emotional functioning in explaining the functional impairments associated with ADHD  need to be examined.In conclusion, this study has taken one important further step in trying to provide a more refined conceptual integration of the different neuropsychological and emotional impairments associated with ADHD. The results emphasized the need to include not only executive functioning but also RT variability and emotional functioning in future theoretical models of ADHD as well as in clinical practice when identifying the major impairments in this diagnostic group.


Accurate classification or prediction of the brain state across individual subject, i.e., healthy, or with brain disorders, is generally a more difficult task than merely finding group differences. The former must be approached with highly informative and sensitive biomarkers as well as effective pattern classification/feature selection approaches. In this paper, we propose a systematic methodology to discriminate attention deficit hyperactivity disorder (ADHD) patients from healthy controls on the individual level. Multiple neuroimaging markers that are proved to be sensitive features are identified, which include multiscale characteristics extracted from blood oxygenation level dependent (BOLD) signals, such as regional homogeneity (ReHo) and amplitude of low-frequency fluctuations. Functional connectivity derived from Pearson, partial, and spatial correlation is also utilized to reflect the abnormal patterns of functional integration, or, dysconnectivity syndromes in the brain. These neuroimaging markers are calculated on either voxel or regional level. Advanced feature selection approach is then designed, including a brain-wise association study (BWAS). Using identified features and proper feature integration, a support vector machine (SVM) classifier can achieve a cross-validated classification accuracy of 76.15% across individuals from a large dataset consisting of 141 healthy controls and 98 ADHD patients, with the sensitivity being 63.27% and the specificity being 85.11%. Our results show that the most discriminative features for classification are primarily associated with the frontal and cerebellar regions. The proposed methodology is expected to improve clinical diagnosis and evaluation of treatment for ADHD patient, and to have wider applications in diagnosis of general neuropsychiatric disorders. Attention deficit hyperactivity disorder (ADHD) is characterized by clinical symptoms of inattention, impulsivity, and hyperactivity. It is one of the most common brain and behavioral disorders among children, which affects 5–8% school age children. ADHD can frequently persist into adolescence and adulthood  which sample an individual is drawn from, because the hippocampal volume of these two samples may have substantially overlapping distributions. In other words, finding group difference only requires a p value that is less than a threshold, while accurately distinguishing the two samples, at the individual level, requires that the two samples to be substantially separated, which requires a highly significant p value. Thus only highly discriminative features  can lead to a good performance in classification.Although there have been extensive studies of ADHD in terms of widespread brain regions and the connectivity patterns, relatively less attention are focused on the pattern classification based on the neuroimaging data of individual ADHD patients, which is crucial for subjective and accurate clinical diagnosis of ADHD  on an individual basis for a large data set. In particular, we will summarize the neuroimaging features that are highly discriminative across the healthy group and the ADHD patients, which include both local measures such as fractional amplitude of low frequency fluctuations (fALFF) . Since the fMRI data collected from different centers may have some systematic differences that are possibly caused by the fMRI machine used, in this paper we only use the fMRI data collected from the Institute of Mental Health and National Key Laboratory of Cognitive Neuroscience and Learning  to minimize variability across institutions. There are 244 children, 143 of which are healthy controls , and the rest 101 are patients with ADHD , including 38 ADHD-Combined (ADHD-C) and 63 ADHD-Inattentive patients (ADHD-I).The fMRI data used in this paper are from the ADHD-200 Consortium for the global competition (All participants (ADHD and controls) are evaluated by the Schedule of Affective Disorders and Schizophrenia for Children—Present and Lifetime Version (KSADS-PL) with one parent for the establishment of the diagnosis. The ADHD Rating Scale (ADHD-RS) IV is employed to provide dimensional measures of ADHD symptoms. All subjects are assessed for intelligence quotients (IQ) on the Wechsler Intelligence Scale for Chinese Children-Revised (WISCC-R) (mean IQ score 113 ± 14.40), and for ADHD index on the 18-item version of the ADHD-RS IV (mean index: 38.31 ± 12.76). Additional inclusion criteria include: (1) right-handedness, (2) no lifetime history of head trauma with loss of consciousness, (3) no history of neurological disease and no diagnosis of schizophrenia, affective disorder, pervasive development disorder, and substance abuse, and (4) a full scale (WISCC-R) score greater than 80.Five subjects  showed large head movements (exceeding 3 mm translation or 3° rotation) and thus are excluded from our analysis.http://www.fmrib.ox.ac.uk/fsl/). Before functional image preprocessing, the first four volumes are discarded to allow for scanner stabilization. Briefly, the remaining functional scans are first corrected for within-scan acquisition time differences between slices, and are then realigned to the middle volume to correct for inter-scan head motions. After this the functional scans are spatially normalized to a standard template  and resampled to 4 mm × 4 mm × 4 mm voxel resolution. After normalization, the Blood Oxygenation Level Dependent (BOLD) signal of each voxel is first detrended to abandon linear trend and then passed through a bandpass filter (0.009 Hz < f < 0.08 Hz) to reduce low-frequency drift and high-frequency physiological noise. Finally, nuisance covariates including head motion parameters, global mean signals, white matter signals, and cerebrospinal fluid signals are regressed out. An automated anatomical labeling (AAL) atlas , have done for us.All functional imaging data are acquired using an acronym for Analysis of Functional NeuroImages (AFNI) and FSL . Amplitude of low-frequency fluctuation (ALFF) measures the magnitude of the fluctuation of the voxel . It is assumed that for a given voxel, its activity is usually correlated to that of its neighbors, and ReHo is used to characterize the degree of local synchronization of spontaneous fMRI signals  by calculating the Kendall coefficient of concordance (KCC) ; Ri is the sum rank of all K voxels at the ith time point; Ri's; K is the number of selected neighboring voxels. Here, we select a given voxel together with its nearest 26 neighbors, that is, K = 27.It has been suggested that many functional brain disease like Alzheimer's disease, schizophrenia, and autism can be described as dysconnectivity syndromes, which is related to the disruption of the connectivity patterns among the spatially distributed brain regions that underlie the normal functioning of the brain Sporns, . The folFunctional brain network by Pearson correlation. The most frequently used functional connectivity measure is the Pearson correlations between regional BOLD time series, which characterizes the synchronization of the regional activity in terms of the low frequency fluctuation. Here the Pearson correlation we use is based on a parcellation of the cortex into 351 brain regions, i.e., CC400 atlases in the competition website (http://www.nitrc.org/plugins/mwiki/index.php/neurobureau:AthenaPipeline) and the Pearson correlation coefficient between regional BOLD signals is computed asxi(t) and xj(t)  are the regional time courses of region i and j with means r-to-z transform is utilized to convert each correlation coefficient to satisfy the assumption of normality. The resultant functional brain network is 351*351, from which we shall extract the most sensitive features  that are used later in the classification.Functional brain network by partial correlation. The functional connectivity revealed by Pearson correlation may not reflect the true interaction between a pair of brain regions, as it does not eliminate the effect from other brain regions that may exert influence to a pair of brain regions in question  and zj(n) are the ith and jth columns of the Pearson correlation matrix obtained above (after Fisher's transformation) with means being t-tests are performed to select the sensitive features from fALFF, ReHo, Pearson correlation, and spatial correlation (CC400 atlases), which show significant differences between the ADHD and healthy control groups; On the other hand, a BWAS is performed to select the features from the functional network derived from partial correlation. In both procedures, statistically significant features  are selected. Note that in each leave-one-out cross-validation (LOOCV) fold, we perform t-tests only on the training samples to select the discriminative features.In the above section, we have listed all the features that we have used and all of them are high-dimensional by nature. For example, CC400 atlases network contains 61425 (351 × 350/2) links among different regions of interest (ROIs). For voxel-level features such as ReHo and fALFF, the corresponding dimensionality can be even higher since they are measured at the voxel level. This high dimensionality in features can lead to the “curse of dimensionality” problem and greatly hamper the performance of the classifier. To reduce the dimensionality of the feature space, on one hand, two-sample two tailed BWAS approach. Since the distribution of partial correlation is generally not Gaussian, traditional two-sample z-test cannot be applied directly. Here we use a BWAS approach to select the significantly altered functional connections  and B respectively. Hence, if NH and NP are large and p, q are not close to 0 and 1, ρH and ρP are approximately normally distributed. More specifically, ρH ~ N/NH) and ρP ~ N/NP) where N is the normal distribution with mean μ and variance σ2. In the present study, we did not consider those links with both ρH and ρP smaller than 0.02 or larger than 0.98 to ensure the validity of this approximation and at the same time release the burden for multiple comparisons. Therefore,S is estimated from the data asp = q and the density of ρH − ρP is then centered at zero. Hence, the p-value for an observed score For a particular link, assume it appears with probability p-values is needed to account for multiple comparisons. In the present study, a false discovery rate (FDR) procedure is used.Since the association is tested for a large number of links, a correction for t-score of two-sample t-test imploded in feature selection, respectively). A two dimensional feature is then obtained by averaging the links in these two groups, respectively. The feature of spatial correlation is integrated in the same way. For Pearson correlation network, the principal component analysis (PCA) . Finally, to extract the key information contained in neuroimaging markers of fALFF and ReHo. Firstly, a multiple comparison is performed to avoid noise voxels. Then we obtain an averaged ReHo value using voxels that are significantly increased in the patient group, which are defined as mean increased ReHo. The mean decreased fALFF value can be acquired in the same way, which results in a two-dimensional feature for these two neuroimaging markers, respectively.To reduce the dimension of each feature, we integrate each high dimensional feature by applying a dimensionality reduction scheme. For example, for partial correlation network , we derive a two dimensional feature by grouping the links in the partial correlation network into two sets: one is composed of links that have a stronger correlation in ADHD patients than in health controls; and the other is composed of links with weaker correlation in ADHD patients , and the remaining subjects as the training data. This is repeated such that each subject is used once as the test data. The accuracy of a classifier is defined as corr/sum, whereas corr denotes the number of correctly classified subjects, and sum denotes the number of total subjects. The sensitivity and specificity evaluate the performance of a classifier to identify positive and negative instances, respectively, and they are defined as below:The framework of our proposed ADHD classification scheme is shown in Figure p < 0.008, which is also used in feature selection), 33.33% (37/122) links are associated with frontal cortex and 23.77% (29/122) links are associated with parietal cortex. It is worthy to note that among these links, the most significantly altered functional connectivity is the link between left hippocampus (HIP.L) and left amygdala (AMYG.L) (p = 2.4e-5) , right precentral gyrus (PreCG.R) and left cuneus (CUN.L) and a decrease in the cerebellum, the bilateral superior frontal gyrus (SFG) and middle frontal gryus (MFG). Additionally, we also find many regions showing increased ReHo (labeled in warm color) in patient group, including the cerebellum, the bilateral LING, cuneus (CUN), Thalamus (THA), precentral gyrus (PreCG), and cingulate gyrus; while only a very small portion of voxels show a decrease in ReHo, including precuneus (PCUN) and medial frontal gyrus.Since both fALFF and ReHo are computed at the voxel level, we obtain two brain maps which reflect the abnormalities of “energy” of the voxels' activity and the local homogeneity in the ADHD patients, see Figures FNI Cox,  and a cop value) used in features selection, with the results shown in Figure p-value threshold being 0.008, the accuracy can reach 76%. Thus the features are more promising in classifying ADHD patients and controls. It should be noted in Table The flowchart of the pattern recognition framework is shown in Figure In this paper, we address the problem of accurately classifying individual state from a large dataset consisting of 141 healthy children and 98 ADHD patients. Using neuroimaging markers derived at different scales, such as fALFF, ReHo, and various kinds of functional connectivity measures, we have identified the most discriminative features for accurate classification on the individual level. The frontal and cerebellar regions are found to change significantly across the two groups, and the correlation between these neuroimaging markers and the ADHD index is also presented. Finally, the further improvement, i.e., a multi-modal approach is discussed to extend our results.ADHD is characterized by clinical symptoms of inattention, impulsivity, and hyperactivity, either alone or in combination. Many neuropsychologists believe the pathophysiology of this disorder may involve dysfunction of frontal–striatal–cerebellar circuits (Krain and Castellanos, As can be seen in Figure In the current paper, we have developed a classifier which can accurately discriminate ADHD patients from healthy controls. Although we have achieved a relatively high accuracy of discrimination, we have much space for further improvements. With BOLD signals, we can include effective networks as further features (Zou et al., The authors declare that the research is performed without any commercial or financial relationships that could be construed as a potential conflict of interest.


We study in details the turnout rate statistics for 77 elections in 11 different countries. We show that the empirical results established in a previous paper for French elections appear to hold much more generally. We find in particular that the spatial correlation of turnout rates decay logarithmically with distance in all cases. This result is quantitatively reproduced by a decision model that assumes that each voter makes his mind as a result of three influence terms: one totally idiosyncratic component, one city-specific term with short-ranged fluctuations in space, and one long-ranged correlated field which propagates diffusively in space. A detailed analysis reveals several interesting features: for example, different countries have different degrees of local heterogeneities and seem to be characterized by a different propensity for individuals to conform to the cultural norm. We furthermore find clear signs of herding  in some countries, but not in others. Based on these empirical results, we proposed that the behaviour of individual agents is affected by a space dependent “cultural field”, that encodes a local bias in the decision making process (to vote or not to vote), common to all inhabitants of a given city. The cultural field itself can be decomposed into an idiosyncratic part, with short range correlations, and a slow, long-range part that results from the diffusion of opinions and habits from one city to its close-by neighbours. We showed in particular that this local propagation of cultural biases generates, at equilibrium, the logarithmic decay of spatial correlations that is observed empirically Empirical studies and models of election statistics is a classical field of Political Economy The aim of the present note is to provide additional support to these rather strong statements, using a much larger set of elections from different countries in the world. We discuss in more depth the approximate universality of the distribution of turnout rates, and show that some systematic effects in fact exist, related in particular, to the size of the cities. We also confirm that the logarithmic decay of the spatial correlations approximately holds for all countries and all elections, with parameters compatible with our diffusive field model. The relative importance of the idiosyncratic, city dependent contribution and of the slow diffusive part is however found to be strongly dependent on countries. We also confirm the universality of the logarithmic turnout rate for different elections, for different regions or for different cities, provided the mean and the width of the distribution is allowed to depend on the city size. Overall, our empirical analysis provides further support to the binary logit model of decision making, with a space dependent mean .We have analysed the turnout rate at the scale of municipalities for 77 elections, from 11 different countries. For some countries, the number of different elections is substantial: 22 from France , the distribution of the shifted LTR Elections Municipales (election of the city mayor), not considered in Régionales of 1998 and 2004. These happen to be coupled with other local elections in half municipalities, which clearly introduces a bias. The distributions Régionales, we find that the KS distance We have extended this analysis to the 9 new election data in France, and to all new countries mentioned above. For France, the not to be identical across different countries. without normalization by its standard-deviation. They are chosen as follows: for Canada and Poland all elections; for France all pure national elections ; for Mexico, Chamber of Deputies in 2003 and 2009; for Germany Chamber of Deputies in 2005 and 2009; all Chamber of Deputies elections for Austria, Spain, Italy and Switzerland; and for Romania, all elections apart from its European Parliament election  the deviation of all  see  and a suintention (or propensity to vote). The final decision depends on the comparison between threshold valueIn order to delve deeper into the meaning of the above results, we need a theoretical framework. In independent decisions, the Central Limit Theorem tells us that:Consider now Let us work out some consequences of the above decomposition, and how they relate to the above empirical findings. Since the cultural field On the other hand, a model where Régionales) for which the average turnout is low, for which the change of concavity is absent; and c) Municipales for which the variation of Municipales: although the As a first approximation, we thus take Municipales elections in France. We therefore find the interpretation of the anomalous If Let us now turn to the distribution of the rescaled variable The last “binomial” term quickly becomes Gaussian as To sum up: the random variable Municipales, i.e. local elections, for which idiosyncratic effects are indeed expected to be large. Note also that the herding ratio is anomalously high for Romania  and in Another striking empirical finding reported in short-ranged correlations, one concludes that the long-range, logarithmic correlations above must come from those of the cultural field Using the above decomposition, and noting that by assumption the fluctuations of ries see .Inspired by a well-known model in statistical physics where these logarithmic correlations appear, we postulated in exact locations of all cities for the different countries under consideration. The results, averaged over many histories of the noise term, are shown in If cities were located on the nodes of a regular lattice of linear size all studied countries . This lends strong support to the existence, conjectured in We conclude that our numerical model reproduces very satisfactorily the observations for In this paper, we have shown that the empirical results for the statistics of turnout rates established in Although we have confirmed the existence of a diffusive cultural field using election data from different countries, we feel that more work should be done to establish the general relevance of this idea to other decision making processes. It would be extremely interesting to find other data sets that would enable one to study the spatial correlations of decision making. An obvious candidate would be consumer habits – for example the consumption pattern of some generic goods, or the success of some movie, etc.Finally, we believe that our detailed analysis of the statistics of turnout rates  reveals both stable patterns and subtle features, that could be used to test for possible data manipulation or frauds, or to define interesting “democracy” indexes. In that respect, the existence of strong herding effects in some countries is somewhat disturbing.5 sigma are not taken into account. For instance let 100 municipalities of size Average values and standard-deviations do not take into account extreme values in order to remove some electoral errors, etc. Electoral values greater than e  as in , each onAppendix S1Details on the data sources and more figures.(PDF)Click here for additional data file.


Attention deficit hyperactivity disorder (ADHD) is the most common neurobehavioral disorder in childhood, affecting large numbers of children throughout the world.Because of the knowledge evolved from ADHD research, today's challenges are vast, including changes in terminology, fears of over-diagnosis, and over-medication of children.What began as a case description, has now evolved in clinical trials, leading from observations of behavior to advances in neuroscience. The biggest challenge remains in the correct diagnosis of ADHD, though.With a worldwide prevalence of approximately 5%, ADHD is very common , some hyperactive-impulsive or inattentive symptoms must have been present before the age of 7 years and there must be clear evidence of interference with developmentally appropriate social, academic, or occupational functioning, e.g., you may have one of the symptoms, but if it is not impairing you or interfering with your functioning, a diagnosis cannot be made. At last but not least, the disturbance does not occur exclusively during the course of other serious mental disorders .In the current DSM, there are three different ways of diagnosing ADHD. There is the combined type, e.g., both core symptoms are met for the past 6 months; there is the predominantly inattentive type and finally the predominantly hyperactive-impulsive type.But what are the strengths of DSM-IV criteria? The committee of experts that has developed the DSM-IV criteria catalog clearly uses rigorous and empirically derived criteria, has looked at all rating scales for diagnosing ADHD and has reviewed the ADHD literature. Additionally, the impairment criterion has been given greater emphasis in the past few years.Nevertheless there are certain weaknesses and controversies of DSM-IV criteria and it is important to have a second look: the age of onset criterion may not be justified (the age of 7 years does seem very restrictive), diagnostic item sets may be inappropriate for different developmental periods , diagnostic thresholds may not apply to older age groups (>16 years), there is no gender distinction in diagnostic thresholds and there is no lower age limit defined (<4 years).So what are potential changes in DSM 5 criteria (American Psychiatric Association,


Attention deficit/hyperactivity disorders (ADHD) and eating disorders (ED) share several clinical features. Research on the association between ADHD and ED is still quite sparse and findings are ambiguous.Correlations between the severity of ADHD key features  and the severity of specific ED symptoms (Structured Interview for Anorexia and Bulimia Nervosa) were examined in 32 female patients diagnosed with ED.r<0.30) and did not reach statistical significance. The only exception was a statistically significant, but counterintuitive association between impulsivity and the avoidance of fattening food.Most correlations between the severity of ADHD features and the severity of ED symptoms were low (The findings in this small sample suggest a weak link between the severity of ADHD key features and the severity of single ED symptoms in female patients with ED. The role of ADHD features for the development, maintenance, and treatment of EDs seems to be intricate and requires further study. The three key features of attention deficit/hyperactivity disorders (ADHD)–inattention, hyperactivity, and impulsivity–are often present in individuals with eating disorders (ED) . Core feIn line with these findings, case-controlled studies found increased prevalence rates of ED in general, and of BN in particular, in ADHD samples compared with control groups (11–16% vs. 2–5%) . FurtherHowever, whether ADHD is really increased in ED is still part of the debate. Study findings vary considerably. Contrasting the findings of Wentz et al. , some moConcerning the subtypes of ED, recent longitudinal research has shown that, whereas the overarching category of ED is relatively stable over time, longitudinal crossover between the ED diagnoses  and between AN subtypes (binge eating/purging AN and restrictive AN) is common and recurrent -20. SuchAlthough ADHD has recently received more attention in adult psychiatry, research on the association between ADHD and ED is still quite sparse and ambiguous. Diagnostic criteria of ADHD varied widely in previous studies and few of them distinguished between symptoms of ADHD (such as inattention) and ADHD diagnosis . MoreoveThe purpose of this study was to systematically examine the associations between the severity of the three ADHD key features  and the severity of ED symptoms and characteristics in individuals with any ED diagnosis in order to provide a more general view on the relationship between ADHD and ED symptoms by adopting a transdiagnostic view on ED.N=32 women diagnosed with a current DSM-IV [This study included Of the participants, 12 (37.5%) were diagnosed with AN, 6 (18.8%) with BN, and 14 (43.7%) with EDNOS. Seven (58.3%) of the AN cases were of the restrictive type, 5 (41.7%) of the binge/purging type. All BN cases were of the binge/purging type.Attention Deficit/Hyperactivity Disorder-Self-Rating (ADHD-SR) screening questionnaire (see below) [Eleven (34%) participants had at least one current comorbid axis I disorder, with anxiety (25%) and depressive (13%) disorders being most frequent. The number of ED patients diagnosed with comorbid ADHD varied between 0 and 28%, depending on the cut-off criteria used in the e below) . EighteeM=23.1, SD=5.6). The mean age at ED onset was 17.1 (SD=4.0) years. At study entry, the participants had on average suffered from ED for 6.0 (SD=4.6) years. The majority of the participants were not married (91%), had no partner (59%), and were in part-time or full-time paid employment (53%). Almost half of the participants (44%) were still in education.The age of the participants ranged between 17 and 46 years  was developed for reliable and valid assessment of the specific and the general psychopathology of ED and provides a measure of the severity of ED symptoms [The symptoms . The SIAAttention Deficit/Hyperactivity Disorder-Self-Rating (ADHD-SR) questionnaire is a German instrument for the diagnosis of ADHD in adults according to DSM-IV or ICD-10 [The r ICD-10 . Eighteer ICD-10 . Evaluatr ICD-10 .Barratt Impulsiveness Scale, Version 11 (BIS-11) is a 30-item self-report measure to assess (1) motor impulsivity, (2) cognitive/attention impulsivity, and (3) non-planning impulsivity [alpha=0.69) and differentiated well between psychiatric patients and control persons. However, the original factor structure was not unambiguously replicated in the German translation [The ulsivity . The Gernslation . So we olsivity,  cognitivnslation ,39.The associations between the degree of severity of ADHD core features and the severity of specific ED symptoms were examined using Pearson’s product-moment correlations (for continuous variables) and Spearman’s rank correlations (for rank-ordered variables). If an ED symptom was present in none or only one participant (e.g. enema use), no correlations were calculated. To control for type I error inflation when performing multiple tests in the same sample, we used Bonferroni corrected alpha levels .M = 62.7, SD = 10.3) than among healthy German controls  = 8.585, P <0.001)  [r = 0.28, P = 0.12), suggesting that the two scales measure different aspects of impulsivity.As is shown in Table r <0.30) , indicatF  = 2.087; P = 0.125; hyperactivity: F  = 0.818; P = 0.495; impulsivity: F  = 2.246; P = 0.105) and in the BIS sum score  = 1.778; P = 0.174).Finally, additional analyses within the specific ED subtypes in our sample  also revealed no significant correlations between ADHD and ED symptoms when controlling for inflated type I error due to multiple testing. . Furthermore, the ED subtypes did not differ significantly on the ADHD-SR scales either  was found between the degree of impulsivity and avoidance of fattening food. In addition to the preponderance of these small and non-significant correlations between the severity of ADHD and ED features, the observed associations were often counterintuitive; positive correlations were found where negative correlations were expected and vice versa. For instance, higher impulsivity was not only statistically significant related to the avoidance of fattening food, but it also tended to be positively correlated with limiting caloric intake, dieting, and excessive fasting. These behaviors all require strict discipline and thus seem not to be very compatible with impulsivity. These preliminary findings, though unexpected, could elucidate an important peculiarity of ED: the extreme control, which is a central symptom of AN patients  could be interpreted as an answer to a primary impulsivity, and explain the frequent diagnostic cross over from AN to BN -20. AlthWhereas our findings suggest that impulsivity might be increased in ED patients compared to healthy controls ,3, it doN = 32) patients in our study, one could suppose that the lack of significant correlations is related to the low statistical power in such a small sample. However, the correlation coefficients, which (unlike significance tests) constitute a measure that is independent of the sample size, in general indicated only small associations between the severity of ADHD and ED characteristics (most r’s < 0.30). For instance, the highest correlation between an indicator of impulsivity (the BIS-11 sum score) and a measure of binge eating (the severity of binge eating episodes) equaled r = 0.218. That is, knowing BIS-11 impulsivity scores enables explanation of less than 5% (r2 = 0.2182 = 0.048) of the variance of the severity of binge eating episodes. It is therefore unlikely that impulsivity scores simply reflect the presence or absence of impulsive eating patterns. In line with this, Davies et al. [r = 0.137), which was also contrary to our expectations.Given the examination of few , however, did not provide any indication of ADHD-ED symptom severity relations in specific ED subtypes. Furthermore, though longitudinal diagnostic flux between specific ED diagnoses is frequent and recurrent, the overreaching diagnosis of ED and the characteristics of ADHD are both relatively stable over time -19. If tIn summary, the findings of this study indicate that the associations between the severity of ADHD features and the severity of specific ED symptoms are low in women diagnosed with ED. This is in line with some previous studies that failed to find increased rates of ADHD in ED ,15. And Among the limitations of this study are the small sample size and the aggregation across specific ED, both of which were discussed earlier. The problem of the relatively small number of patients in this study is accentuated when performing analyses within specific ED subtypes. Thus, our null-findings resulting from subgroup analyses should be treated with caution. They maybe just reflect the need for larger samples. Further research is needed to examine associations between the severity of specific ADHD and ED symptoms in ED subtypes.Structured Clinical Interview for DSM-IV Disorders[As a further potential limitation of this study, we used self-report questionnaires (ADHD-SR and BIS-11) to assess ADHD characteristics. The Disorders, which iDisorders. NeverthDisorders. FinallyDespite the small sample, our study suggests that ADHD key features such as impulsivity may be increased in individuals with ED, but that their severity does not play a crucial role regarding the severity of specific ED symptoms. Although ADHD is frequently observed in ED individuals, the relation between these two disorders seems to be complex at the level of specific symptoms and features. Further research is needed to elucidate the association between the severity of ADHD features and the severity of specific ED symptoms.The authors declare that they have no competing interests.CG, CM, AS, and GM designed the study. CG was responsible for data collection. NS performed the statistical analyses. NS, UH, and GM were involved in the interpretation of the data. NS, UH, and GM drafted the manuscript. All authors reviewed the manuscript several times and have read and approved the final version of the manuscript.The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1471-244X/13/44/prepub


There is limited evidence of the unmet needs and experiences of adults with Attention Deficit Hyperactivity Disorder (ADHD) in the published scientific literature. This study aimed to explore the experiences of adults in England with ADHD regarding access to diagnostic and treatment services, ADHD-related impairment and to compare experiences between patients diagnosed during adulthood and childhood.In this qualitative study, 30 adults with ADHD were recruited through an ADHD charity (n = 17) and two hospital outpatient clinics for adults with ADHD in England (n = 13). Half of the participants were diagnosed with ADHD during childhood or adolescence and the remainder during adulthood. Semi-structured interviews were conducted and data was analysed using a thematic approach based on Grounded Theory principles.uphill struggle’, often due to sceptical and negative attitudes towards ADHD by healthcare professionals. ADHD-related impairment had an overwhelmingly chaotic impact on every aspect of patients’ lives and many felt ill equipped to cope. A persistent sense of failure and missed potential from living with the impact of ADHD impairment had led to an accumulated psychosocial burden, especially among those diagnosed from late adolescence onwards. In contrast, positive adjustment was facilitated by a younger age at diagnosis. Although medication was perceived as necessary in alleviating impairment, many felt strongly that by itself, it was inadequate. Additional support in the form of psychological therapies or psycho-education was strongly desired. However, few patients had access to non-pharmacological treatment. In some, medication use was often inadequately monitored with little or no follow-up by healthcare professionals, leading to poor adherence and a sense of abandonment from the healthcare system.Analysis revealed five core themes: ‘An uphill struggle’: the challenge of accessing services, ‘Accumulated Psychosocial Burden and the Impact of ADHD’, ‘Weighing up Costs vs. Benefits of ADHD Pharmacological Treatment’, ‘Value of Non-pharmacological Treatment’ and ‘Barriers to Treatment Adherence’. Accessing services and the challenges associated with securing a definitive diagnosis of ADHD in adulthood was an ‘The findings suggest that the unmet needs of adults with ADHD are substantial and that there is a wide gap between policy and current practice in England. Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder, which, until recent years, has been perceived as a disorder restricted to childhood . Yet folIn addition, many adult patients with ADHD have gone unrecognised and undiagnosed in childhood and approach health services to seek help for the first time in adulthood . ADHD isRecent guidelines by the National Institute of Health and Clinical Excellence (NICE) have recommended pathways of care for children and adults with ADHD in the UK ,21. In pTherefore, this study aimed to better understand the health care and treatment-related experiences and needs of adults with ADHD, specifically, to explore: a) patients’ experiences of accessing services and receiving a diagnosis of ADHD; b) patients’ experiences of ADHD treatment, both pharmacological and non-pharmacological; c) patients’ experiences of ADHD-related impairment; and finally, d) to compare the experiences between adult patients diagnosed in childhood and in adulthood.A qualitative approach using semi-structured interviews was used as it enabled a detailed and in-depth exploration of patients’ experiences and views. Moreover, the technique is particularly useful at improving knowledge of poorly understood areas of health care ,23. FaceParticipants were eligible for the study if they had received a diagnosis of ADHD (self-reported), were over 18 years old, living in England, and had previous or current experience of ADHD pharmacological treatment for a minimum duration of 3 months. Participants were ineligible if they were unable to participate in a face-to-face interview. Stratified sampling was used to recruit a total of 30 participants from two different subgroups of adult ADHD patients:Group 1: Adult patients who were diagnosed and commenced pharmacological treatment for ADHD during childhood or adolescence (under age 18).Group 2: Adult patients who were diagnosed and commenced pharmacological treatment for ADHD during adulthood (aged 18 or over).Both groups included participants who had been on treatment without a break (continuous care), and others who had periods of at least 6 months without care or treatment (non-continuous care). In total, 15 participants were recruited where ADHD was first diagnosed in adulthood and 15 were recruited where the diagnosis was made during childhood or adolescence. This sample size is deemed sufficient in qualitative research  in terms) and research governance approval from appropriate NHS Trust sites. Patient interviews were conducted between December 2010 and June 2011. Participants were recruited via two methods and the process is summarised in Figure Ethical approval was obtained from the Cambridgeshire 1 National Health Service (NHS) ethics committee (REC reference: 10/H0304/20Semi-structured face-to-face interviews were conducted in either the participant’s home (n = 15), in a private room at the School of Pharmacy in London (n = 12) or at an alternative convenient location (n = 3). A semi-structured interview guide was developed by a multi-disciplinary team including two psychologists, a pharmacist and a psychiatrist. This was used to guide the discussion in each individual interview, and enabled the interviewer to follow-up on any unanticipated issues that arose during interviews. Written informed consent was obtained from all participants prior to interview. Participants were reassured that the interviews were confidential and transcripts would be anonymised. The interview guide involved a series of open-ended questions, and topics included accessing services, treatment  and ADHD-related impairment. Prompts were used where necessary to elicit more detailed responses. Participants were free to respond in their own words and the researcher followed up on topics that arose outside of the interview guide. The interviews lasted approximately 1 hour and were digitally-recorded, with participants’ consent. Field notes were written up after each interview which recorded the researcher’s thoughts, feelings and reflections about the interview.In order to describe the sample, participants also completed a brief survey to obtain self-reported demographic characteristics, prescription medication use, and ADHD symptoms and impairment. The symptom severity checklist is a validated questionnaire also known as the Adult ADHD Self Report Scale (ASRS v.1) . The impInterviews were transcribed verbatim and a general thematic approach was used to analyse the transcripts using key principles of Grounded Theory ,28. A GrA reflexive research diary was kept during the entire research process by LM to record any thoughts regarding emerging codes or ideas resulting from the analysis . To ensuQuantitative data was entered and analysed using SPSS v. 18 ™. As data were collected for descriptive purposes, only descriptive statistics were performed. Self-reported demographic characteristics and prescription medication use were reported as mean (SD) for continuous variables or n (%) for categorical variables. For the ASRS  scale, pThirty participants were included in this study. The sample included 15 participants diagnosed in childhood or adolescence (of which 8 had continuous care) and 15 participants diagnosed in adulthood (of which 8 had continuous care). There were 13 males and 17 females with an age range of 18 to 57 years . The response rate from ADDISS was 15%, excluding those who were ineligible or responded after study completion. Excluding those who responded after the study finished, the response rate from the NHS outpatient clinics was 19%. An overview of recruitment is shown in Figure Participants reported that they were diagnosed with ADHD between the ages of 6 and 57 years . In participants diagnosed in adulthood, the mean age at diagnosis was 40.93 years (SD =9.32), and 11.07 years (SD = 4.50) in participants diagnosed in childhood. As expected, there were differences between participant groups in terms of age, due to inherent age differences in the subgroups of interest.Patients self-reported medical and treatment characteristics data is reported in Table The mean total score was 13  out of a total of 18, which indicates moderate symptom burden across the sample. Participants diagnosed in adulthood had numerically higher mean total scores  compared to those diagnosed in childhood . The mean number of items which indicated that ADHD impairment was definitely present was 5 out of a total of 10 . Participants diagnosed in adulthood had numerically higher mean scores for impairment  than those diagnosed in childhood . Twenty seven per cent of the sample reported mild symptom severity, 63% reported moderate and 10% reported severe symptom severity. This demonstrates that the sample included a range of different symptom severities.An uphill struggle’: the challenge of accessing services,‘Accumulated Psychosocial Burden and the Impact of ADHD’,‘Weighing up Costs vs. Benefits of ADHD Pharmacological Treatment’, ‘Value of Non-pharmacological Treatment’ and ‘Barriers to Treatment Adherence’ with a common thread of ‘Unmet needs’ which runs throughout participants’ experiences of treatment and accessing services.Five meta-themes emerged from the qualitative data: ‘These themes and subthemes are presented below, with illustrative quotes from study participants.I had to fight tooth and nail for two years to get this on the NHS, it was extremely difficult” P4). Many faced multiple barriers to getting care, often perceived by patients to be due to overwhelmingly negative and sceptical attitudes towards ADHD by health professionals. Some General Practitioners (GPs) were perceived by patients as unwilling to refer to specialist services because of disbelief in the condition or poor awareness of adult ADHD (“It was an uphill struggle” P3). Getting a definitive diagnosis of ADHD was a challenge in those without access to specialist care. In a few who initially accessed adult ADHD care in countries outside the UK (mainly in the United States); there was a stark contrast between these positive experiences and the difficulties encountered upon accessing continued care in England.Getting a diagnosis and accessing ADHD services was often a long and arduous process, particularly in those diagnosed in adulthood (“Putting somebody with ADHD through a bureaucracy is torture.... it’s like treating a diabetic in a bakery” P21). Due to these emotional difficulties, a few with particularly negative experiences of accessing care even considered whether getting a diagnosis was worthwhile, because of the lack of subsequent support received .Participants reported that the struggle of getting access to services in adulthood exacerbated their feelings of disempowerment, distress and helplessness and led to a downward spiral in functioning. In several cases, delays in accessing care left participants feeling unable to cope, prompting periods of severe functional impairment, depressive mood and even suicidal ideation . Some participants recalled periods of time where their doctor refused to prescribe the medication for them; this varied from several days to several years. Patients reported that this was often due to doctors who held negative attitudes towards prescribing ADHD medication or health trusts that refused to fund medication. These periods of enforced cessation were highly distressing, and long periods without medication led to severe emotional distress and functional impairment in some.Accessing prescription medication for ADHD was also problematic, as some patients reported GPs being unwilling to prescribe, or had encountered pharmacists who were reluctant to stock or dispense ADHD medication. Therefore, some had to take multiple trips to the pharmacy every month to collect medications, which was stressful due to difficulties in getting organised and remembering . Overall, more positive experiences of using ADHD services in adulthood were reported from those diagnosed during childhood, or with access to private healthcare.Some reported problems with transitioning from child to adult services, such as discontinuation of treatment or support upon reaching 18, or delays with referrals to adult services . Some participants were distressed at being unable to access ADHD specialist care and being placed on repeat prescriptions by their GP, without monitoring or support. This was deemed inadequate at meeting their needs and resulted in feelings of abandonment by the healthcare system, especially in those treated since childhood. For example, many participants whose primary interaction was with a GP strongly desired support with adjusting their medication type and dosage, or advice regarding coping with side effects, but did not receive it. Evidently, those with little support by health professionals reported poorer self-efficacy (confidence in their ability to effectively self-manage their condition).A few participants experienced problems communicating difficulties associated with their ADHD to their GP, and reported becoming overly emotional during initial consultations . Some desired greater involvement in treatment decision-making and access to a wider range of ADHD medication in order to improve functioning and reduce side effects. In contrast, those with access to ADHD specialist care reported that they received and strongly valued this type of support.In those who had experienced severe difficulties accessing care, a few participants felt unwilling to disclose the negative effects of pharmacological treatment to physicians over fears of medication being withheld . In addition, participants often experienced problems remembering to attend healthcare appointments, and they felt the need for easier access to care, such as more telephone follow-up consultations.Many participants desired more frequent monitoring and support, although others did already receive this. Some participants perceived an unwillingness amongst health professionals to help patients adjust medication types or dosages, which was deemed important to find optimal treatment and reduce side effects .Participants who went undiagnosed until adulthood often initially sought help from health care services due to depression or anxiety complaints, which resulted in years of misdiagnoses. The cause of co-occurring disorders was attributed by many of these patients to the underlying ADHD, as they reported long-term ADHD symptoms since childhood. Many reported that treatments for these disorders were ineffective as they failed to address core symptoms of the ADHD. Those diagnosed from later adolescence onwards perceived this as a ‘late’ diagnosis and felt a strong sense of regret and frustration over a lack of earlier detection . The emotional impact of living with undiagnosed ADHD had led some to psychological breakdown and suicidal ideation as they felt unable to cope with the burden of impairment. Prominent feelings of low self-worth in some participants were impacted by a sense of underachievement as well as having experienced on-going negative criticism and labelling by others.In most participants diagnosed in adulthood, living with undiagnosed ADHD had led to an accumulated psychosocial burden due to a chronic sense of failure and missed potential in many areas of life (““It affects you in every single way possible” P26). For many participants, a chronic sense of disorganisation was particularly debilitating, due to symptoms of poor concentration and memory . Home and working lives were often chaotic as many participants constantly struggled with completing routine tasks, chronic forgetfulness, prioritising or managing time appropriately.The impact of ADHD impairment was not limited to those with a delayed diagnosis, but affected the whole sample. In many participants, ADHD related impairment had an overwhelmingly chaotic impact on every aspect of patients’ lives. Many had struggled with the transition into independent adult life, and often felt ill equipped to cope . A few female participants reported internalised hyperactivity, such as overactive thoughts and finding it difficult to relax . Overall, the burden of impairment appeared greater in those with a delayed diagnosis (from late adolescence onwards), and positive adjustment to ADHD seemed to be facilitated by an earlier age at diagnosis.Emotional impairment was evident in all participants, particularly overreactions of frustration or anger, as many had difficulty coping with emotions which could become overwhelming. Some experienced periods of emotional breakdown and functional disability, as they were unable to complete simple tasks. According to participants, ADHD was detrimental to physical wellbeing, due to difficulties transitioning from sleep to wake and vice versa. Participants diagnosed in childhood perceived certain ADHD symptoms to have lessened since adolescence, particularly hyperactivity, although many reported feelings of restlessness or being constantly it was like putting on a pair of glasses for vision; I found them excellent when it comes to concentration…it does lift the fog” P14). Medication also improved feelings of normalcy . Drug treatment was often perceived as vital to daily functioning and was deemed necessary at improving focus in work or educational situations involving routine tasks or written assignments. The impact on social impairment was varied, as some felt medication enabled them to function better in social situations. Medication was thought to be beneficial at reducing emotional impairment, particularly in younger participants who felt more able to control anger or restlessness and hyperactivity.All participants discussed the benefits of pharmacological treatment, as many felt medication lessened the chaotic impact of ADHD, such as disorganisation and procrastination. Some participants felt that their cognitive abilities and memory were improved while on medication and several thought it improved their ability to focus on tasks .Participants also weighed up the negative aspects of pharmacological treatment. Around two thirds of the sample reported side effects, which varied greatly between participants, such as insomnia, headaches or poor appetite. A few reported severely impairing side effects such as paranoia and many experienced daily withdrawal symptoms as medication wore off. Some participants perceived a loss of self-identity, and felt that medication diminished positive aspects of ADHD, such as sociability (“I need to know the reasons why I’m taking it [medication] and what effects I can expect because otherwise the negative sides of things outweigh it” P10). In addition, a few participants expressed disappointment over medication effects, and perceived a lack of long-term improvement, particularly in the group diagnosed in adulthood that had medication as a standalone treatment. Some participants who felt that the disadvantages of medication outweighed the advantages, were also more often in this group, than those diagnosed in childhood. A few participants also reported overenthusiastic psychiatrists raising overly high expectations of medication effectiveness.A few treated from an early age felt that medication effectiveness reduced in the long-term, which meant changing drug type every few years. More negative beliefs towards drug effectiveness were found in those who had received inadequate specialist support to find optimum treatment (“It’s been a life saver for me” P21), many participants, particularly those diagnosed from late adolescence onwards, felt that medication as a standalone treatment was limited. These participants reported a plethora of unmet psychosocial needs as many strongly desired additional psychological or educational support alongside medication to improve functioning. However, few had access to non-pharmacological treatment . Most participants felt that the system of care should offer more holistic treatment programs . In particular, improving organisational and coping skills, reducing stress and alleviating social and emotional impairments was deemed necessary by many.Overall, although most participants felt that drug treatment was necessary at alleviating ADHD impairment . Treatments such as Cognitive Behavioural Therapy (CBT), Counselling or Life Coaching were deemed beneficial by some, particularly at helping patients learn practical coping strategies and deal with the psychosocial burden. The social element of group therapy or support sessions was highly valued, enabling participants to learn how others coped with ADHD . Yet, some thought psychosocial treatments should be better designed and more appropriate for ADHD patients in terms of being more engaging and accessible. Participants diagnosed in childhood reported greater access to psychosocial treatments whilst in child services, but these were often discontinued in adulthood. However, despite reporting greater access, these participants placed less value on the usefulness of non-pharmacological treatments, compared to participants diagnosed in adulthood. A few felt the timing of psychosocial treatments was inappropriate in adolescence and would be more useful in helping them to cope with adulthood challenges .Equal value was placed on psychosocial and pharmacological treatments by those with experience of both treatment types, who felt that medication alongside additional psychosocial support was particularly effective (““I just take them for exams now or if there’s something going on that I find a struggle” P1), not liking to take medication during weekends or holidays and perceived lack of guidance from clinicians .Issues of medication non-adherence (e.g. missing doses) and experimenting with treatment cessation (longer periods of medication cessation) also arose in the interviews. Participants gave several explanations for occasionally not taking their medication as prescribed. The most commonly reported reason for non-adherence was forgetfulness but other reasons included only taking the medication when it was perceived as needed , who deemed this as a ‘late’ diagnosis. Based on participants overall accounts of managing their ADHD, those diagnosed in childhood appeared more positively adjusted to the condition and reported fewer psychosocial and service-related unmet needs, compared to those diagnosed in adulthood. However some of those diagnosed in childhood did experience problems transitioning from child to adult services; similar to findings reported previously which suggests that pharmacological treatment in young adults with ADHD may be discontinued prematurely by health care professionals ,33. EvidThis study highlights that adult patients with a delayed diagnosis of ADHD have many unmet needs regarding treatment. According to NICE guidelines ,21, all Evidently, those patients with experience of both treatment types placed equal value on pharmacological and non-pharmacological treatments, and appeared more positively adjusted to the condition. The potential value of psycho-education, particularly when combined with medication has been highlighted in a recent review of care for children with ADHD . There aThere were stark differences in the experiences of those with and without access to specialist ADHD care. Some participants were placed on repeat prescriptions by their GP and went unmonitored with drug regimes, which was deemed completely inadequate by participants, and is neither in line with current ADHD policy nor with NICE guidelines ,21. ThisThere are several limitations of the current study. The findings are based on a relatively small sample size. However, this number is typical in qualitative research and thematic saturation was achieved . There wFurther quantitative research is warranted to assess the true extent of unmet needs in the wider adult ADHD population in the UK as well as other countries with different healthcare system. Additionally, further research is necessary to design and evaluate more appropriate psychosocial interventions for providing educational and psychological support for adults with ADHD, as there is limited research in this area. Furthermore, exploring physicians’ perceptions and experiences of treating adult ADHD patients may also indicate areas for improvement in the system of care.The current study indicates where improvements to practice and policy are urgently needed so that patients’ needs are met. Firstly, NICE guidelines  need to This study highlights the challenging process of accessing adequate ADHD diagnostic and treatment services, which can have a damaging impact on adult patients with ADHD. The findings indicate that a substantial psychosocial burden exists in adult ADHD patients, particularly those diagnosed from late adolescence onwards. This study also demonstrates the potential need for better psychological and educational support for adults with ADHD, especially patients who have a delayed diagnosis. Overall, these findings highlight the wide gap between recent NICE guidelines ,21 and cADHD: Attention deficit hyperactivity disorder; GP: General practitioner; NHS: National Health Service; NICE: National Institute of Health and Clinical Excellence; ADDISS: National Attention Deficit Disorder Information and Support Service; ASRS: Adult ADHD self report scale; SD: Standard deviation.LM, SC, PA and IW had support from Shire Pharmaceuticals LLC for the submitted work; PH and JS are employees of Shire Pharmaceuticals Inc, and RS was an employee of Shire Pharmaceuticals at the time the submitted work was commissioned and is currently an employee of Bayer Pharmaceuticals. PH and JS own stocks in Shire Pharmaceuticals. In the previous 3 years, LM and SC have had no other relationships or activities that could appear to have influenced the submitted work. PA has conducted consultancy work for Shire Pharmaceuticals, Eli Lilly, Janssen Cilag and Flynn Pharma. PA has grants/grants pending with Shire Pharmaceuticals, Janssen Cilag, Vifor and QB Tech. PA has received payment for lectures from Shire Pharmaceuticals, Flynn Pharma, Janssen Cilag, Eli Lilly and Medice. In the previous 3 years, IW has conducted consultancy work for Shire Pharmaceuticals, and received payment for lectures by Janssen Cilag.SC, IW and PA initiated the idea for the study and led development of the protocol, securing of funding and ethical approval. RS, PH and JS contributed to the protocol. LM and SC were responsible for the study administration, recruitment, data collection, data analysis, interpretation of results, and writing of the paper. LM and SC were the only authors who had full access to all the data in the study and can take responsibility for the integrity of the data and the accuracy of the data analysis. LM and SC wrote the initial draft of the paper, to which all the authors contributed. All authors read and approved the final manuscript.LM has a background in Health Psychology and was a Research Assistant at The School of Pharmacy at the time the study was conducted and the paper written, and is now a PhD student at Oxford Brookes University; PA is a Professor of Molecular Psychiatry; IW is a Professor of Pharmacy; PH and JS are employees of Shire Pharmaceuticals with backgrounds in pharmacy; RS was an employee of Shire Pharmaceuticals at the time the study was conducted and the paper written, and is now an employee of Bayer Pharmaceuticals; SC was a Lecturer in Medicines in Health at The School of Pharmacy at the time this study was conducted and the paper written, and is now a Research Scientist in Outcomes Research at United BioSource Corporation.The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1472-6963/13/184/prepub