A comparative study of the effectiveness of group-based cognitive behavioral therapy and dialectical behavioral therapy in reducing depressive symptoms in Iranian women substance abusers

Various therapeutic approaches have been used to improve depressive symptoms in substance abusers. In a quasi-experimental study with a pretest-posttest design and experimental and control groups, we examined and compared the effectiveness of two group-based treatment strategies—cognitive behavioral therapy (CBT) and dialectical behavioral therapy (DBT)—in reducing depressive symptoms among Iranian women substance abusers. The statistical population included all female addict patients who referred to addiction treatment centers of Birjand city in 2015. A sample of 30 subjects were selected through the available sampling method and randomly assigned into experimental (CBT and DBT) and control groups (each group, 10 patients). The data collection instrument was the Beck Depression Inventory (BDI) questionnaire. The patients in the experimental groups were given skills in eight sessions of 90 min. The data were analyzed by the SPSS-19 software by using mean, standard deviation, and percentages at the descriptive level and analysis of covariance (ANCOVA) test at the inferential level. The comparison of the mean depression score before intervention in all the groups showed no significant difference. However, after intervention, the findings showed that both CBT and DBT interventions could reduce the mean scores of depression in women substance abusers, 17.5 ± 3.0 vs 29.3 ± 4.1 (F[1,17] = 51.91, p value < 0.01) and 14.7 ± 1.8 vs 29.3 ± 4.1 (F[1,17] = 106.62, p value < 0.01), respectively, for CBT and DBT. Post-treatment effect sizes were large and did not differ statistically for CBT (η(p)(2), 0.75) and DBT (η(p)(2), 0.86). Therefore, this study highlights the importance of CBT and DBT skills training to substance abusers and provides initial evidence of their effectiveness.