Recent evidence supports the efficacy of conference call cognitive-behavioral interventions in preventing depression in caregivers at post-intervention, but we do not know whether the results are sustained long term. The main objective of this study was to evaluate the long-term efficacy of a cognitive-behavioral intervention administered by telephone conference call in preventing depression in caregivers with elevated depressive symptoms, comparing all components of the intervention versus only the behavioral ones. A randomized controlled trial was conducted using a dismantling strategy. At total of 219 caregivers were randomly assigned to a cognitive-behavioral conference call intervention (CBCC; n = 69), a behavioral-activation conference call intervention (BACC; n = 70), or a usual care control group (CG, n = 80). Information was collected on depressive symptoms and depression at pre-intervention and at 1, 3, 6, 12, and 36 months post-intervention. At 36 months, there was a reduction in depressive symptoms (p < 0.001) and a lower incidence of major depressive episodes in both the CBCC and BACC groups compared to CG (8.7%, 8.6%, and 33.7%, respectively). The results show that a conference call intervention was effective in the long term to prevent depression in caregivers and that the behavioral-activation component was comparable to the complete cognitive-behavioral protocol.
Keywords: cognitive–behavioral intervention; depression; dismantling; long-term efficacy; non-professional caregiver; prevention; telephone.