Painful physical symptoms and antidepressant treatment outcome in depression: a systematic review and meta-analysis

Background Painful physical symptoms (PPS) are highly prevalent in patients with major depressive disorder (MDD). Presence of PPS in depressed patients are potentially associated with poorer antidepressant treatment outcome. We aimed to evaluate the association of baseline pain levels and antidepressant treatment outcomes. Methods We searched PubMed, Embase and Cochrane Library databases from inception through February 2023 based on a pre-registered protocol (PROSPERO: CRD42022381349). We included original studies that reported pretreatment pain measures in antidepressant treatment responder/remitter and non-responder/non-remitter among patients with MDD. Data extraction and quality assessment were performed following the Preferred Reporting Items for Systematic Reviews and Meta-analyses by two reviewers independently. The primary outcome was the difference of the pretreatment pain levels between antidepressant treatment responder/remitter and non-responder/non-remitter. Random-effects meta-analysis was used to calculate effect sizes (Hedge’s g) and subgroup and meta-regression analyses were used to explore sources of heterogeneity. Results A total of 20 studies were included. Six studies reported significantly higher baseline pain severity levels in MDD treatment non-responders (Hedge’s g = 0.32; 95% CI, 0.13–0.51; P = 0.0008). Six studies reported the presence of PPS (measured using a pain severity scale) was significantly associated with poor treatment response (OR = 1.46; 95% CI, 1.04-2.04; P = 0.028). Five studies reported significant higher baseline pain interference levels in non-responders (Hedge’s g = 0.46; 95% CI, 0.32–0.61; P