cardiovascular diseases , such as coronary heart disease ( chd ) , are among the leading causes of death in western countries and in iran ( 1 ) . these disorders are responsible for more than 25% of all deaths worldwide ( 2 ) . in the uk , for example , more than 90,000 people die from chd each year ( 3 ) . according to the world health organization , chronic disease causes 70% of deaths globally , with chd ranking first ( 4 ) . it is reported that the age at onset of cardiovascular disease in iran is approximately 7 - 10 years earlier than in other countries ( 5 ) . chd s physical and psychosocial consequences not only increase the mortality rate , but also considerably increase disability rates for a large portion of the country s workers during their best years of productivity , ultimately reducing productivity and increasing the cost of healthcare ( 6 , 7 ) . studies have shown that 30% - 72% of chd patients demonstrate symptoms of depression , and 40% - 65% show symptoms of anxiety ( 8 - 10 ) . these two problems , in addition to lack of social support , are among the most common psychological responses in patients with cardiovascular disease , and they not only increase the use of healthcare services , but also the risk of disease relapse or exacerbation ( 11 ) and the costs of acute and long - term healthcare ( 12 ) . lifestyle changes are also recommended in order to eradicate or decrease the underlying factors ( 13 ) . in recent years , alternative therapies , such as music therapy , relaxation , therapeutic massage , and guided imagery , have been used to decrease patients anxiety and distress related to acute and chronic disorders ( 14 ) . in addition to the measures cited previously , studies indicate reduced distress , anxiety , depression , and certain psychological problems through the use of psychological treatments , such as cognitive - behavioral therapies , psychoeducational programs ( peps ) , and the establishment of support systems . recently , researchers have focused on using peps as a fundamental treatment for patients psychological problems ( 12 ) . peps are usually aimed at directing the patients learning , providing opportunities for them to express their emotions in a safe environment , creating real hope or strengthening it , offering solutions to enhance the patients self - awareness , and providing opportunities for them to practice their new knowledge ( 15 - 17 ) . several studies have investigated the effects of peps on mental health and psychological problems in patients with different disorders . luciano et al . ( 18 ) studied the effect of a pep on the general health of patients with fibromyalgia , and reported that the intervention was effective at improving mobility and reducing pain , fatigue , morning tiredness , anxiety , and depression . ( 19 ) reported that psychological interventions that provide a supportive environment and cognitive - behavioral therapy can reduce symptoms of depression and anxiety in cancer patients undergoing radiotherapy , improving their health - related quality of life . however , in a meta - analysis of peps , dusseldorp et al . reported that these methods did not significantly affect anxiety ( 10 studies ) or depression ( 13 studies ) in patients with chd ( 20 ) . moreover , hartford et al . investigated the impact of telephone - based psychological training with nurses and reported that the intervention did not significantly affect the patients anxiety after coronary artery bypass grafting ( cabg ) ( 21 ) . in another study , johnston et al . also examined the effects of education and psychological counseling on anxiety , depression , and functional limitations in patients with myocardial infarction ; the results showed that the intervention did not significantly affect depressive symptoms ( 22 ) . in a recent systematic review of psychological interventions for chd patients and their partners , reid et al . reported that the effects of psychological interventions for patients with chd were inadequately studied , and that the available studies were mostly out dated and of poor overall quality , including methodological weaknesses , and they showed a non - significant trend ( 8) . therefore , further studies in the field of psychological interventions for chd patients are needed . a majority of the studies on peps have been conducted on patients with psychiatric disorders , while being limitedly implemented in patients with medical disorders , especially cardiovascular disease . however , healthcare providers , including doctors and nurses , have increasingly found that in addition to tending to the physical aspects of patients , it is necessary to pay more attention to their psychosocial needs in order to help them achieve normal lives ( 23 , 24 ) . therefore , indigenous forms of peps may be useful for patients with chronic disease , such as chd , to help them reach maximum functional health ( 12 , 25 ) . this study aimed to examine the effects of a pep intervention on the mental health of chd patients . this randomized controlled trial was conducted on 70 patients with chd who were hospitalized in the coronary care unit ( ccu ) at shahid beheshti hospital in kashan , iran , in 2014 . according to previous studies ( 12 ) and based on the formula of  = 0.95 , 1 -  = 0.8 , and d = 0.65 , the sample size was determined to be 35 patients in each group . the subjects who met the inclusion criteria were randomly allocated into experimental and control groups through a randomized block sampling method . the inclusion criteria were age of 21 - 65 years , willingness to participate in the study , ability to respond to inquiries and attend meetings , no history of angioplasty or cabg , absence of brain disorders ( such as alzheimer s , stroke , or transient ischemic attack ) , and ability to read and write in the persian language . the exclusion criteria were death or migration , the occurrence of any acute or urgent medical or psychological upheaval , and the patient s decision to leave the study . for controlling the confounding variables , patients with substance addictions or known mental and psychological disorders were excluded from the study . the intervention group underwent eight group sessions of pep , two sessions per week at two - day intervals , with each session lasting for 45 - 60 minutes . data on the patients demographics were collected at the start of the study . at the same time , the primary outcome measures were collected for the two groups . in addition to routine medical care , the experimental group received pep intervention , which included discussions and training materials on skills for coping with anxiety , with an emphasis on lifestyle , anger management , problem - solving and muscular relaxation techniques , as presented in box 1 ( 26 - 28 ) . all pep sessions were facilitated by a trained nurse . at the end of each session , assignments were given to the participants to complete at home . the participants experiences with the assignment were reviewed and discussed at the start of the next session , and then new materials were delivered . during the intervention period , the investigator conducted a 5 - 10 minutes weekly telephone call with each participant in the intervention group to track the home assignments , answer questions , and organize the sessions . the study questionnaire was re - answered by each participant in the intervention group after the eight pep sessions . patients in the control group only received routine medical care , plus a training pamphlet from the american heart association containing information on general cardiac healthcare ( 29 ) . these participants answered the study questionnaire at the beginning of the recruitment and again after four weeks . the first part contained questions about socio - demographic characteristics ( the patient s age , gender , surgical history , and smoking ) . the second part of the instrument was goldberg s general health questionnaire ( ghq ) . the ghq consists of 28 items that are rated on a three - point likert scale . the scale has four dimensions : somatic symptoms , anxiety , social dysfunction , and depression . the overall score of the scale indicated the individual s level of mental health , with higher scores indicating a lower level of mental health ( 30 ) . ahmadian ( 31 ) confirmed the instrument s content validity and assessed its reliability through the internal consistency method , and cronbach s alpha ranged from 0.77 to 0.90 for the different subscales . in another study , ebrahimi et al . reported cronbach s alpha for the overall persian scale to be 0.97 ( 32 ) . permission for this study was obtained from the ethics committee of kashan university of medical sciences . ethical issues in this study involved the assurance of confidentiality and the anonymity of the participants . all participants were informed of the purpose and design of the study , and understood that their participation was voluntary . this study was registered in the iranian registry for clinical trials ( irct ) with registration code 2014060114086n4 . kolmogorov - smirnov was used to examine the normal distribution of variables , and the chi - square test was used to compare the distribution of socio - demographic variables in the two groups . the independent - sample t - test was used to examine the difference between the mean ages of the two groups . the independent - sample t - test was also used to examine the differences between the overall ghq mean scores , as well as the subscale mean scores in the two groups at the start and the end of the study . in addition , the paired - sample t - test was used to compare the changes in the overall ghq mean scores of the individual groups at the start and the end of the study . data on the patients demographics were collected at the start of the study . at the same time , the primary outcome measures were collected for the two groups . the pep was then initiated in the intervention group . in addition to routine medical care , the experimental group received pep intervention , which included discussions and training materials on skills for coping with anxiety , with an emphasis on lifestyle , anger management , problem - solving and muscular relaxation techniques , as presented in box 1 ( 26 - 28 ) . all pep sessions were facilitated by a trained nurse . at the end of each session , assignments were given to the participants to complete at home . the participants experiences with the assignment were reviewed and discussed at the start of the next session , and then new materials were delivered . during the intervention period , the investigator conducted a 5 - 10 minutes weekly telephone call with each participant in the intervention group to track the home assignments , answer questions , and organize the sessions . the study questionnaire was re - answered by each participant in the intervention group after the eight pep sessions . patients in the control group only received routine medical care , plus a training pamphlet from the american heart association containing information on general cardiac healthcare ( 29 ) . these participants answered the study questionnaire at the beginning of the recruitment and again after four weeks . the first part contained questions about socio - demographic characteristics ( the patient s age , gender , surgical history , and smoking ) . the second part of the instrument was goldberg s general health questionnaire ( ghq ) . the ghq consists of 28 items that are rated on a three - point likert scale . the scale has four dimensions : somatic symptoms , anxiety , social dysfunction , and depression . the overall score of the scale indicated the individual s level of mental health , with higher scores indicating a lower level of mental health ( 30 ) . ahmadian ( 31 ) confirmed the instrument s content validity and assessed its reliability through the internal consistency method , and cronbach s alpha ranged from 0.77 to 0.90 for the different subscales . in another study , ebrahimi et al . reported cronbach s alpha for the overall persian scale to be 0.97 ( 32 ) . permission for this study was obtained from the ethics committee of kashan university of medical sciences . ethical issues in this study involved the assurance of confidentiality and the anonymity of the participants . all participants were informed of the purpose and design of the study , and understood that their participation was voluntary . this study was registered in the iranian registry for clinical trials ( irct ) with registration code 2014060114086n4 . kolmogorov - smirnov was used to examine the normal distribution of variables , and the chi - square test was used to compare the distribution of socio - demographic variables in the two groups . the independent - sample t - test was used to examine the difference between the mean ages of the two groups . the independent - sample t - test was also used to examine the differences between the overall ghq mean scores , as well as the subscale mean scores in the two groups at the start and the end of the study . in addition , the paired - sample t - test was used to compare the changes in the overall ghq mean scores of the individual groups at the start and the end of the study . a p value of < 0.05 was selected as significant in all tests . the findings of the present study showed that pep improves mental health and decreases somatic and psychological symptoms , such as anxiety and depression , in patients with chd . of the total participants , three in the intervention group were excluded from analysis due to irregular participation . two participants in the control group died , and another was excluded from analysis due to incomplete answers on the post - test questionnaire . in total , the data of 64 patients were analyzed ( figure 1 ) . no significant differences were found between the two groups in terms of socio - demographic variables ( table 1 ) . ( % ) except age that is presented as mean  sd . the independent - sample t - test was used to examine the differences between the two groups in terms of the means of overall ghq scores , as well as the mean scores of the ghq subscales at the start of the study , and no significant differences were observed in these respects ( p > 0.05 ) . however , the means of the overall ghq scores and most of the ghq subscales were significantly decreased post - test in the intervention group , so that the differences between the two groups were statistically significant in both the overall ghq scores and in all of the subscales ( p < 0.05 ) ( tables 2 and 3 ) . using the paired t - test , a significant difference was observed between the mean overall ghq scores of the intervention group prior to and after the pep intervention ( 30  4.66 vs. 20.50  3.30 ) ( p < 0.0001 ) . however , no significant changes were observed in the control group between before the study and after ( p > 0.07 ) ( table 4 ) . the findings of this study showed that pep improves mental health by decreasing somatic and psychological symptoms , such as anxiety and depression , in patients with chd . this finding is consistent with the results of taylor - rodgers and batterham , who studied the effects of pep intervention on the help - seeking attitudes and intentions among young adults with regard to mental health ( 12 ) . luciano et al . ( 18 ) and guo et al . ( 19 ) have also reported that psychological training could reduce anxiety and depression in patients with fibromyalgia or cancer . peps combine methods of relaxation with psychological training , such as anger management and problem - solving techniques . several studies have used single methods , such as anger management or relaxation , and reported positive effects . for instance , ahangarzade and ezadi reported that anger management training could improve mental health in nursing students ( 33 ) . ( 10 ) and dehdari et al . ( 11 ) used relaxation and distraction in patients with cardiac disorders and post - cardiac surgery , and reported that these methods were effective in reducing patients anxiety . some studies , such as d'souza et al.s also used psychological training , and reported that this method was effective not only in reducing the severity of anxiety and depressive symptoms , but also in decreasing the rate of relapse in patients with bipolar disorder ( 26 ) . it seems that peps have a positive effect on anxiety , depression , and mental health , not only by decreasing muscular tension but also by combining relaxation with improved anger management and problem - solving skills . this could be attributed to differences in the content and techniques used ( 34 ) , or to the methods and time - intervals . for example , various studies implemented psychological training methods through telephone contact , email , or cds ( 21 , 22 ) . it appears that pep shave a positive impact on mental health , especially if it is applied in a face - to - face approach and is tailored to the individual s culture and lifestyle . in general , it seems that pep changes the patient s mental framework , increases his or her awareness of the present moment , and improves the cognitive and information - processing systems . moreover , group - session peps show more benefits in facilitating and speeding up the treatment process ( 14 , 35 , 36 ) , as they allow patients to be gathered in one place to discuss their problems . this intervention reduces patients tensions , relieves their negative emotions , and improves their social relationships ( 37 ) . therefore , it is recommended that such programs be used in conjunction with other treatments . this study had some limitations , including its non - blind design and the short follow - up period . moreover , the psychological status of the patients while answering the questionnaire , and the level of information or support they received from sources other than the investigators , were not under the researchers control . psychoeducation is a well - known intervention for psychiatric patients , but its use has been limited in other health conditions , such as coronary heart disease . the results of this study show that pep has positive effects on the mental health of patients with chd . further studies are suggested , with greater sample sizes and longer follow - up periods at different time - intervals . studies are also suggested on the barriers to and facilitators of using pep in practice . considering the important psychological needs of patients with coronary heart disease , it is suggested that similar interventions be integrated into routine cardiac care plans , and that pep interventions be added to medical and nursing education curricula .