Explaining how a psychosocial intervention (PROACTIVE) based on behavioural activation improved outcomes of depression in older adults living in deprived regions of Brazil: The mediating roles of reduced loneliness and stepped care

Background

The PROACTIVE trial was a task-shared, stepped and collaborative care, psychosocial intervention based on psychoeducation and behavioural activation in 715 participants (60–94 years; mean (SD) 68·6 (6.9) years; 74·1 % female), that was highly effective at improving recovery from depression among older adults in Brazil. Here we investigate mediators of the intervention's effectiveness.

Methods

Causal mediation analysis using interventional indirect effects, simultaneously decomposed the total effect of PROACTIVE on recovery from depression (PHQ-9 < 10) into multiple indirect effects including: dose of intervention (numbers of sessions and activities completed); social support (Luben Social Network Scale); perceived loneliness (UCLA questionnaire); and additional sessions offered to participants who did not respond during the initial phase of the stepped care intervention.

Results

Of the intervention's total effect (difference in probability of recovery from depression between the intervention and control arms 0·216 [bias-corrected 95 % CI: 0·149, 0·291]): 13 % was mediated through reduced loneliness (0·028 [0·013, 0·046]); and 25 % through attending additional sessions for participants who did not initially respond to the intervention (0·055 [0·007, 0·102]).

Limitations

Due to limitations in our sample size our study may lack power to detect some nuances such as interactions between different mediators.

Conclusions

Our findings emphasise the importance of a home-based intervention to improve depression outcomes where participants are encouraged to self-select activities to mitigate against loneliness. Importantly, our findings suggest that the intervention's stepped-care component offering additional sessions to participants who did not experience an early response shows promise in ensuring a sustained recovery from depression.