BACKGROUND: Cognitive behavioural analysis system of psychotherapy (CBASP) is an effective individual treatment for persistent depressive disorder (PDD), but evidence on group treatment (Group-CBASP) is limited. Our aim was to review the effect of Group-CBASP on self-report depression severity in outpatients with PDD, overall and by age of depression-onset.
METHODS: A retrospective chart review study (November 2011-March 2017) in 54 patients with PDD (29 late-onset, 25 early-onset). Patients were previously treated by pharmacotherapy (92.6%), psychotherapy (98.1%) and/or electroconvulsive therapy (11.1%). Group-CBASP involved 24 weekly sessions during 6 months, followed by individual appointments over 6 months. The Inventory of Depressive Symptoms -self rating(IDS-SR) was used at baseline and after 3, 6, 9 and 12 months, computing mean differences and response rates.
RESULTS: The mean IDS-SR score decreased significantly from 39.83 at baseline to 33.78 at 6 months: a decrease from severe to moderate depression after 24 weeks of Group-CBASP, with a medium effect size (Cohen's d = .49). At 12 months, the mean IDS-SR score was 32.81, indicating moderate symptom levels remained. At 6 and 12 months, mean IDS-SR scores were similar among late- versus early-onset patients, but at 12 months response rates were higher among late-onset patients.
LIMITATIONS: Although results of our study provide valuable input for future prospective studies, limitations were the use of a retrospective design and the small group size.
CONCLUSION: Group-CBASP offered to an outpatient population with PDD was associated with clinically relevant decrease in self-reported symptom severity, and with sustained response particularly in patients with late onset of depression.
PRACTITIONER POINTS: Group-CBASP seems to be a good alternative for CBASP in individual setting. Patients with late age of depression-onset seem to benefit more from Group-CBASP. This study shows that clinical relevant effects of Group-CBASP, followed by individual contacts, remain at least for 6 months. Research on personalizing treatment strategies is needed to improve patient assignment for Group-CBASP.