Do all roads lead to Rome? A qualitative process evaluation of two types of group-based Behavioural Activation following acquired brain injury from the MAPLES feasibility trial

Background: Approximately 1 in 3 acquired brain injury (ABI) survivors will have post-ABI depression. Behavioural Activation (BA), an intervention that encourages engagement in positively reinforcing activities, shows promise. Here, we conduct a process evaluation of two group-based BA interventions for adults with ABI. Methods: Adults (≥18 years) recruited from local ABI services, charities, and self-referral via social media were randomised to receive either “Traditional” BA (scheduling and engaging in positively reinforcing activities combined with cognitive management strategies) or “Experiential” BA (participating in reinforcing activities within-session but without explicit attempts to plan between-session activities). Interventions were delivered once weekly over 8 weeks. A semi-structured interview at 1-month follow-up focused on participants’ perspectives of intervention benefits and processes associated with mood and activity levels. Data were collected in-person and, due to COVID-19, remotely. Results: N=49 participants completed interviews (Traditional BA n=25, Experiential BA n=24). A positive therapeutic milieu, a sense of group cohesion and being able to share common ABI-related experiences were felt to foster psychological safety, reduce social isolation and underlie mood/activity improvements by participants in both groups. Processes more strongly linked to Traditional BA included developing their skillset in coping with low mood, avoidance and cognitive barriers to activity engagement, aligning scheduled activities to values, and challenging negative thinking patterns. Conversely, processes more strongly linked to Experiential BA were increased in-session enjoyment, participating in activities in sessions enhancing present-mindedness, and having choice and control into selecting within-session activities. Conclusions: Positive group processes may enhance outcomes associated with group-based BA delivered to adults with ABI. Specific methods of delivering group-based BA may have differing underlying mechanisms that should be captured and maximised in BA intervention delivery in ABI, including value-based activity scheduling and promoting autonomy in session content. Trial Registration: Clinicaltrials.gov, NCT03874650. Protocol version 2.3, May 26th 2020.