Obsessive-compulsive disorder in childhood and adolescence. Empirically supported therapies according to the psychological variables involved

The main aim of this study was to investigate the role of comorbidity in the treatment of OCD in children and adolescents. This study used a single-subject design with multiple baselines and changing criteria (Kazdin, 2002), in which the treatment of one clinical case could be seen as a replication of the treatment of previous cases. Firstly, the effect of CBT on OCD in a sample of ten children and adolescents was examined. Second, the treatment program, CBT, was split in two components, psychoeducation and ERP, to distinguish the effect of psychoeducation from the effect of the combined treatment (ERP plus psychoeducation). Third, the potential additional effect of treating comorbid conditions was examined. Finally, the potential additional effect of a second application of ERP (after appropriate treatment of the comorbid conditions) was studied. Data analysis was conducted on the scores of each participant and subsequently on the combined scores of the total sample. To estimate the effect size of treatment from one phase to the next, the Tau-U index (Parker, Vannest, & Davis, 2011) was calculated on all repeated measures from each patient and, second, on the merged scores obtained for the total sample. CBT was highly effective in a first group of participants, reducing the frequency and severity of every obsessive-compulsive symptom. However, a second group of participants, those with a comorbid condition, did not significantly respond to CBT, or did respond but in less extension that the first group. Results show that there were very few statistically significant improvements in the variables during psychoeducation but showed a strong improvement from psychoeducation to ERP. The treatment of comorbid conditions led to their significant improvement and also strongly improved obsessive-compulsive symptoms, especially among the participants who still fulfilled the diagnostic criteria for OCD. Furthermore, when a second OCD treatment was applied, the results show that ERP at this time led to a significant and strong improvement in all of the previously unresponsive participants. In summary, the results of this study strongly suggest that the treatment of conditions comorbid with OCD could be a key factor in increasing the effect of CBT for OCD and, more importantly, it could be crucial in obtaining improvements in patients who would otherwise be unresponsive to CBT.