The Effects of Psychological Interventions on Conduct Disorder in Iran: A Meta-Analysis

 The increasing prevalence of mental disorders in children is an essential issue given its impact on children's development and function. According to the review of the literature of pathology in developmental psychology, the behavioral emotional disorders of childhood are divided into two main categories; eternalizing disorders and internalizing disorders. Conduct Disorder (CD) is among the most common eternalizing disorders for which various treatment models have been proposed. It is important to pay attention to the child with CD along with their environment in the treatment; thus, we performed this meta–analysis to clarify the precise effect size of psychological interventions for treating children's CD. Therefore, we aimed at reviewing data and ultimately performing a meta–analysis on the effect size of psychological therapies of this disorder.

This was a meta–analysis study. To collect the related research, keywords, like “conduct disorder and psychological treatment for conduct disorder, emotional behavioral disorders, the effectiveness of parenting, social skills training, verbal self–learning, play, and story therapy on conduct disorder”, were searched in domestic search databases, including www.sid.ir, www.magiran.com, www.noormags.ir, and www.ensani.ir. Accordingly, 99 related articles were studied from 2005 to 2020. The inclusion criteria included scientific research articles related to the mentioned keywords regarding psychological therapies, dissertations published in the form of articles in scientific–research journals, clinical trial studies, and studies that specifically depended on reducing CD symptoms. The exclusion criteria were articles presented at conferences, seminars, research related to non–psychological therapies, such as medication, review articles, and statistics lacking a control group. Moreover, according to the Consolidated Standards of Reporting Trials (CONSORT) checklist, the emphasis was on the title and abstract, the type of intervention, objectives, and hypotheses, inclusion criteria, sample size, randomization, statistical methods, and research results. After removing duplicates and reviewing the quality of the articles by 3 experts in psychology and statistics, 6 articles were finally selected. After calculating the standardized difference between the mean scores, those studies were meta–analyzed by a random model at the significance level of 0.050 in the Review Manager.

The meta–analysis data on the comparison of the mean difference respecting the scores of reduced CD symptoms between the intervention and control groups indicated that in all these studies, the reduction rate of CD symptoms in the intervention group was significantly higher than that in the control group. By dividing the difference between the calculated mean values of the studies by the standard deviation of the differences, a standardized difference of the averages was obtained, which made facilitated comparing the mean scores of the research. The mean difference of the standardized score for all these studies equaled 1.6 (1.25, 1.95) which indicated the effect size of psychological interventions. The random model was used in the analysis and heterogeneity was studied using Chi–squared and I2</sup> index. According to the Chi–squared test data (Q=8.58, df=6, p</em>=0.200), due to the significance at the error level of 0.050, the test statistic was not significant; thus, the studies were not heterogeneous. The I2</sup> index was measured as <50% (I2</sup>=30%), suggesting the homogeneity of the studies. Therefore, the meta–analysis revealed the significant effect of the psychological interventions in reducing CD symptoms (Z=8.95, p</em><0. 001). Furthermore, the lack of the intersection of the horizontal line with the confidence interval of each study with the vertical line of the accumulation diagram indicated the statistical significance; ultimately, these data reflected the effect of psychological interventions on reducing CD symptoms.

The present study findings supported the effects of psychological therapies (including parenting styles training, social skills training, verbal self–learning training, play therapy, & story therapy) on reducing CD symptoms. Therefore, applying psychological therapies is useful for treating CD.