Process for screening and diagnosing ASD; M-CHAT is Modified Checklist for<unk>  in Toddlers; (+) is positive test result; (-) is negative test result ASD can be detected as early as 18 months or even younger in some cases. A reliable diagnosis can usually be made by the age of two years, however, because of delays in seeking and administering assessments, diagnoses often occur much later. A study in 2005 found that children diagnosed with<unk> ic disorder and PDD-NOS are typically diagnosed at age 3 while children with Aspergers are typically diagnosed at age 7. The diverse expressions of ASD behavioral and observational symptoms and absence of one specific genetic or molecular marker for the disorder pose diagnostic challenges to clinicians who use assessment methods based on symptoms alone. Individuals with an ASD may present at various times of development (e.g., toddler, child, or adolescent), and symptom expression may vary over the course of development. Furthermore, clinicians who use those methods must differentiate among pervasive developmental disorders, and may also consider similar conditions, including intellectual disability not associated with a pervasive developmental disorder, specific language disorders, ADHD, anxiety, and psychotic disorders. Ideally the diagnosis of ASD should be given by a team of professionals from different disciplines (e.g. child psychiatrists, child neurologists, psychologists) and only after the child has been observed in many different settings. Considering the unique challenges in diagnosing ASD using behavioral and observational assessment, specific practice parameters for its assessment were published by the American Academy of Neurology in the year 2000, the American Academy of Child and Adolescent Psychiatry in 1999, and a consensus panel with representation from various professional societies in 1999. The practice parameters outlined by these societies include an initial screening of children by general practitioners (i.e., "Level 1 screening") and for children who fail the initial screening, a comprehensive diagnostic assessment by experienced clinicians (i.e. "Level 2 evaluation"). Furthermore, it has been suggested that assessments of children with suspected ASD be evaluated within a developmental framework, include multiple informants (e.g., parents and teachers) from diverse contexts (e.g., home and school), and employ a multidisciplinary team of professionals (e.g., clinical psychologists, neuropsychologists, and psychiatrists). , psychologists would wait until a child showed initial evidence of ASD tendencies, then administer various psychological assessment tools to assess for ASD. Among these measurements, the<unk>  Diagnostic Interview-Revised (ADI-R) and the<unk>  Diagnostic Observation Schedule (ADOS) are considered the "gold standards" for assessing<unk> ic children. The ADI-R is a semi-structured parent interview that probes for symptoms of<unk>  by evaluating a child's current behavior and developmental history. The ADOS is a semistructured interactive evaluation of ASD symptoms that is used to measure social and communication abilities by eliciting several opportunities (or "presses") for spontaneous behaviors (e.g., eye contact) in standardized context. Various other questionnaires (e.g., The Childhood<unk>  Rating Scale,<unk>  Treatment Evaluation Checklist) and tests of cognitive functioning (e.g., The Peabody Picture Vocabulary Test) are typically included in an ASD assessment battery. Screening US and UK screening recommendations for<unk>  in children younger than 3 years are: * US Preventive Services Task Force does not recommend universal screen of young children for<unk>  due to poor evidence of benefits of this screening when parents and clinicians have no concerns about ASD. The major concern is a false-positive diagnosis that would burden a family with very time-consuming and financially demanding treatment interventions when it is not truly required. The Task Force also did not find any robust studies showing effectiveness of behavioral therapies in reducing ASD symptom severity * American Academy of Pediatrics recommends ASD screening of all children between the ages if 18 and 24 months. The AAP also recommends that children who screen positive for ASD be referred to treatment services without waiting for a comprehensive diagnostic workup * The American Academy of Family Physicians did not find sufficient evidence of benefit of universal early screening for ASD * The American Academy of Neurology and Child Neurology Society recommends general routine screening for delayed or abnormal development in children followed by screening for ASD only if indicated by the general developmental screening * The American Academy of Child and Adolescent Psychiatry recommend routinely screening<unk>  symptoms in young children * The UK National Screening Committee does not recommend universal ASD screening in young children. Their main concerns includes higher chances of misdiagnosis at younger ages and lack of evidence of effectiveness of early interventions Misdiagnosis There is a significant level of misdiagnosis of<unk>  in neurodevelopmentally typical children; 18–37% of children diagnosed with ASD eventually lose their diagnosis. This high rate of lost diagnosis cannot be accounted for by successful ASD treatment alone. The most common reason parents reported as the cause of lost ASD diagnosis was new information about the child (73.5%), such as a replacement diagnosis. Other reasons included a diagnosis given so the child could receive ASD treatment (24.2%), ASD treatment success or maturation (21%), and parents disagreeing with the initial diagnosis (1.9%). Many of the children who were later found not to meet ASD diagnosis criteria then received diagnosis for another developmental disorder. Most common was ADHD, but other diagnoses included sensory disorders, anxiety, personality disorder, or learning disability. Neurodevelopmental and psychiatric disorders that are commonly misdiagnosed as ASD include specific language impairment, social communication disorder, anxiety disorder, reactive attachment disorder, cognitive impairment, visual impairment, hearing loss and normal behavioral variation. Some behavioral variations that resemble<unk> ic traits are repetitive behaviors, sensitivity to change in daily routines, focused interests, and toe-walking. These are considered normal behavioral variations when they do not cause impaired function. Boys are more likely to exhibit repetitive behaviors especially when excited, tired, bored, or stressed. Some ways of distinguishing typical behavioral variations from<unk> ic behaviors are the ability of the child to suppress these behaviors and the absence of these behaviors during sleep. Comorbidity ASDs tend to be highly comorbid with other disorders. Comorbidity may increase with age and may worsen the course of youth with ASDs and make intervention/treatment more difficult. Distinguishing between ASDs and other diagnoses can be challenging, because the traits of ASDs often overlap with symptoms of other disorders, and the characteristics of ASDs make traditional diagnostic procedures difficult. * The most common medical condition occurring in individuals with ASDs is seizure disorder or epilepsy, which occurs in 11–39% of<unk> ic individuals. * Tuberous sclerosis, an autosomal dominant genetic condition in which non-malignant tumors grow in the brain and on other vital organs, is present in 1–4% of individuals with ASDs. * Intellectual disabilities are some of the most common comorbid disorders with ASDs. Recent estimates suggest that 40–69% of<unk> ic individuals have some degree of an intellectual disability, more likely to be severe for females. A number of genetic syndromes causing intellectual disability may also be comorbid with ASD, including fragile X, Down, Prader-Willi, Angelman, Williams syndrome and SYNGAP1-related intellectual disability. * Learning disabilities are also highly comorbid in individuals with an ASD. Approximately 25–75% of individuals with an ASD also have some degree of a learning disability. * Various anxiety disorders tend to co-occur with ASDs, with overall comorbidity rates of 7–84%. Rates of comorbid depression in individuals with an ASD range from 4–58%. The relationship between ASD and schizophrenia remains a controversial subject under continued investigation, and recent meta-analyses have examined genetic, environmental, infectious, and immune risk factors that may be shared between the two conditions. Oxidative stress, DNA damage and DNA repair have been postulated to play a role in the aetiopathology of both ASD and schizophrenia. * Deficits in ASD are often linked to behavior problems, such as difficulties following directions, being cooperative, and doing things on other people's terms. Symptoms similar to those of attention deficit hyperactivity disorder (ADHD) can be part of an ASD diagnosis. * Sensory processing disorder is also comorbid with ASD, with comorbidity rates of 42–88%. * Starting in adolescence, some people with Asperger syndrome (26% in one sample) fall under the criteria for the similar condition schizoid personality disorder, which is characterised by a lack of interest in social relationships, a tendency towards a solitary or sheltered lifestyle, secretiveness, emotional coldness, detachment and apathy. Asperger syndrome was traditionally called "schizoid disorder of childhood".
Autism spectrum
Tardive dysmentia
Outline of autism
Nonverbal autism
Multiple complex developmental disorder
High-functioning autism
Low-functioning autism
Zellweger spectrum disorders