The World Health Organization states that around 280 million people worldwide suffer from depression, which is the second leading cause of years lived with disability globally (Global Burden Disease, 2019). Moreover, up to 54% of individuals who have experienced a depressive episode are at risk of relapse (Bockting et al., 2015). Relapse is the return of the initial episode of depression after some improvement, while recurrence is the onset of a new episode after recovery (Moriarty et al., 2021).
Previous research has explored both pharmacological (Cipriani et al., 2018) and non-pharmacological strategies (Buckman et al., 2018) to prevent relapse and recurrence of depression. It has been recommended that psychological interventions be more widely available globally to identify those who may benefit the most (Patel et al., 2023).
However, current meta-analyses use aggregate data, limiting the ability to make treatment recommendations based on individual characteristics. Individual participant data meta-analysis (IPDMA) can help overcome these limitations. IPDMA collects individual data from each participant in the studies included, allowing for the analysis of patient subgroups and more accurate outcomes (Tudur Smith et al., 2016).
This study systematically searched for randomized controlled trials published until January 2021 to evaluate the efficacy of psychological interventions in preventing depression relapse and recurrence. Types of therapy examined included Psychodynamic Psychotherapy, Cognitive-Behavioural Therapy, Mindfulness-Based Cognitive Therapy, and Continuation Cognitive Therapy compared to non-psychological interventions and treatment-as-usual (TAU).
The IPDMA included 14 studies with 1,720 participants. Psychological interventions outperformed control conditions in delaying relapse, especially for patients with multiple past depressive episodes. Psychological interventions were effective both as stand-alone treatments and as add-ons to TAU. The analysis identified two predictors for outcomes: residual symptoms of depression at baseline and experiencing more than two previous episodes of depression.
Despite the promising results, caution is necessary before implementing these findings in clinical practice. Replication studies are needed, and further research could investigate the specific effects of different psychological treatments in preventing relapse. IPDMA’s reliance on available data and difficulty in obtaining IPD from existing trials were noted as limitations.
Overall, these findings suggest that psychological interventions are effective in reducing the risk of depression relapse and recurrence, particularly for patients with a history of multiple episodes. Further research and validation are needed before widespread clinical application.
