BackgroundAcquired brain injuries (ABI) from stroke, head injury, or resected brain tumours are associated with poor emotional wellbeing and heightened risk of mood disorder. Common sequalae of ABI, such as poor attention and memory, can create barriers to the efficacy of cognitively demanding mood interventions, such as Cognitive Behavioural Therapy (CBT). Behavioural Activation (BA), where individuals plan and engage in reinforcing activities, is a promising alternative due to lower cognitive demands. However, BA was initially developed in clinical populations without ABI where the primary barriers to activity engagement were low mood and anxious avoidance. Additionally, BA can incorporate a range of techniques (e.g., mood monitoring, activity scheduling, targeting avoidance, contingency management) and psychoeducational topics (e.g., mindfulness, managing uncertainty; social/communication skills). Exploring barriers and facilitators to adopting specific BA components in ABI is an important aim.MethodsSemi-structured interviews were conducted with purposively selected ABI survivors (N= 16) with both low and high depressive symptoms, and family members (N= 7). Questions focused on routine and enjoyable activities, and feedback on 10 different BA techniques and associated psychoeducational topics. Transcripts were analysed using an interpretive description framework. Analysis was informed by field notes, reflexivity diaries, and peer debriefing.ResultsThe final constructed framework,Creating Sustainable Engagement,comprises a two-tier hierarchy. Higher-level themes concerned core perspectives of BA, regardless of BA component discussed. This included identifying optimal time windows for different BA components (Right Tool at the Right Time),that BA components should, at least initially, not be burdensome or fatiguing (Perceived Effort), that emotional readiness to confront activity-mood relationships should be addressed (Emotional Impact),and that planned BA activities be consistent with individual values (Relation to Values).Lower-level themes concerned specific BA components: Of these, activity scheduling, procedures targeting avoidance, managing uncertainty and social/communication skills were generally well-received, while mood monitoring, contingency management, and mindfulness had mixed feedback.ConclusionsBA is a widely scalable intervention that can be adapted for ABI. This study provides a novel framework on implementing a range of BA components in ABI and adds to the limited evidence on which components may be particularly suitable.Supplementary InformationThe online version contains supplementary material available at 10.1186/s40359-023-01230-2.