Evaluating the efficacy of psychotherapeutic and pharmacological treatments for depression on anhedonia: A systematic review and meta-analysis

BACKGROUND: Anhedonia, the lack of interest or pleasure in activities, is a core but under-addressed symptom of depression. Consequently, little is known about the efficacy of treatments for alleviating anhedonia. OBJECTIVE: To evaluate the efficacy of psychotherapeutic and pharmacological treatments for depression at reducing symptoms of anhedonia. METHODS: Embase, International Pharmaceutical Abstracts, Medline, PsycINFO, and the Cochrane Library were searched from inception-June-2025 for Randomised Control Trials of evidence-based (defined by National Institute for Health and Care Excellence NICE guidelines) psychotherapeutic or pharmacological treatments for depression in adults that used validated anhedonia outcome measures. Random-effects meta-analyses examined endpoint differences in anhedonia symptoms. RESULTS: 22 studies (27 comparisons, n = 3287) included. There was a small effect of treatments on anhedonia compared to inactive controls (Standardised Mean Difference SMD = 0.26 95 % Confidence Interval [CI = 0.10;0.43], p = 0.004). There was no evidence of a differential effect of any treatments when compared with NICE-recommended active-treatment controls. There was no evidence of moderation by risk of bias, treatment length or intensity, and weak evidence of moderation by format; face-to-face psychotherapeutic interventions were more efficacious than remotely delivered (telephone/video-call). CONCLUSION: Treatments for depression were more efficacious at alleviating anhedonia relative to wait-list/no-treatment, placebo, or usual care. Effect sizes for anhedonia change were smaller than those for overall depression symptoms found in previous meta-analyses. There was no evidence of differential efficacy between different active treatments. Given the significance of anhedonia in depression, future studies focused on optimising treatment effects on anhedonia are required, it also needs to be routinely measured as a key outcome, in a consistent fashion.