Many randomized controlled trials have demonstrated that cognitive behavioural therapy (CBT) is an effective treatment for depression and anxiety problems. However, many patients who receive CBT often do not maintain their positive outcomes after treatment, and instead experience a relapse of symptoms. The common occurrence of relapse after CBT not only has a detrimental impact on the lives of the patients who experience them, but also on healthcare service costs and efficiency, due to a ‘revolving door’ process whereby patients return for further treatment. Therefore, there is a humanitarian and health economic need to better understand how to improve the longer-term outcomes of CBT.
A recent systematic review and meta-analysis attempted to address this knowledge gap by reviewing the current literature on predictors of relapse of depression following CBT. The review estimated a pooled relapse rate for depression of 33.4% across 13 studies, and identified two well-supported predictors of depressive relapse: higher levels of depression symptoms at the end of treatment (residual symptoms), and prior episodes of depression. However, little is known regarding what factors are associated with anxiety-related relapse.
Therefore, we aimed to address this gap in the literature by systematically reviewing the contemporary literature on predictors of relapse of anxiety-related disorders following CBT. A total of nine studies met eligibility criteria (N=532), and a pooled relapse rate for anxiety of 23.8% was estimated. The nine studies investigated a total of 147 variables as potential predictors of relapse, with 21 significant predictors (p<0.05) being identified. These predictors can be grouped into seven categories: residual symptoms; personality disorders; medication; clinical features; stressful life-events; degree of improvement; and demographics. A meta-analysis of residual symptoms as a predictor of relapse yielded a moderate but non-significant-pooled effect size (r=0.35; 95% CI -0.21, 0.74, p = .08).
Our findings suggest that approximately one in four patients who receive clinically effective CBT for anxiety-related disorders experience a relapse following treatment. This highlights the importance of relapse prevention as being a valued and fundamental component of the treatment process. However, knowledge regarding what factors cause or influence relapse remains limited, with little research having been conducted in this area, and there being numerous limitations associated with the research that has been conducted. For example, the studies included in this review were limited by small sample sizes and inconsistent definitions of relapse. Indeed, only one of the nine studies investigated a sample that included more than 20 relapse cases, and only one pair of studies used the same measure of relapse. These major limitations likely prevented important predictors from being identified, and contributed to differences between studies in terms of their respective findings. Therefore, further research with adequately powered samples, and standardized measures and definitions of relapse is needed. This will enable more risk factors to be discovered and established, and thus facilitate the development of evidence-based relapse prevention interventions that can be targeted at those patients at greatest risk of relapse.
Read the full paper: Lorimer, B., Kellett, S., Nye, A., & Delgadillo, J. (in press). Predictors of relapse and recurrence following cognitive behavioural therapy for anxiety-related disorders: A systematic review. Cognitive Behaviour Therapy. doi:10.1080/16506073.2020.1812709
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