Integrating behavioural activation for depression into community drug and alcohol treatment

One in two patients seeking help for substance use disorders (SUDs) have clinically significant depressive symptoms. This comorbidity is associated with poor treatment outcomes, yet the testing and implementation of evidence-based interventions for this group has been slow to occur. Behavioural Activation (BA) is an evidence-based psychological treatment for depression. Emerging evidence suggests that BA holds promise as a treatment for SUD patients with comorbid depressive symptoms, but it is currently unclear whether implementing BA in routine care would improve treatment outcomes. Understanding BA in the context of implementation in SUD treatment may lead to more definitive conclusions regarding the value and adoptability of the intervention, which could help facilitate its translation into practice. Therefore, this thesis sought to conduct a preliminary investigation of the effectiveness and acceptability of integrating BA into community drug and alcohol treatment (CDAT) to treat patients with comorbid SUD-depression. First, a systematic review and meta-analysis (Chapter 2) of randomised controlled trials (RCTs) was conducted to clarify the effectiveness and acceptability of BA for comorbid SUD-depression based on existing evidence. No significant differences were found between BA and controls with regard to depression or substance use outcomes, although BA appeared to be an acceptable treatment option with a comparable dropout rate to controls. Chapter 3 then reports on a pilot RCT of BA facilitated by drug and alcohol treatment workers in CDAT. Compared to Treatment as Usual (TAU), BA was associated with significant improvements in Percent Days Abstinent (PDA) and progress in valued living at 6-week follow-up, along with significant reductions in depressive symptoms and improvements in PDA at 12-week follow-up. However, these effects were not maintained at 24-week follow-up. The BA dropout rate was 59%. Chapter 4 expands on these findings by exploring the experiences of clinical managers, BA therapists (drug and alcohol treatment workers) and BA patients from the pilot trial. Staff and patients discussed the acceptability of delivering evidence-based interventions in CDAT, concerns around patient engagement with BA, challenging yet helpful aspects of BA and the compatibility of BA with routine care. Finally, the overall theoretical, clinical and policy implications of findings from this thesis are discussed in Chapter 5, with recommendations outlined for future research investigating BA as a treatment for comorbid SUD-depression in CDAT