Associations between somatic symptoms and remission of major depressive disorder: A longitudinal study in China

Previous studies have documented negative associations between somatic symptoms and remission of major depressive disorder (MDD). However, the correlations of specific somatic symptoms with remission remain uncertain. We aimed to explore the associations between specific somatic symptoms and remission focusing on sex differences among patients with MDD. We used data from patients with MDD in the Depression Cohort in China. At baseline, total somatic symptoms were evaluated using the 28-item Somatic Symptoms Inventory and were categorized into pain, autonomic, energy, and central nervous system (CNS) symptoms. To measure remission of MDD, depressive symptoms were evaluated using the Patient Health Questionnaire-9 after 3 months of treatment. We ultimately included 634 patients. Compared with quartile 1 of total somatic symptom scores, the full-adjusted ORs (95% CIs) for remission from quartile 2 to quartile 4 were 0.52 (0.30, 0.90), 0.44 (0.23, 0.83), and 0.36 (0.17, 0.75), respectively (P-value for trend = 0.005). The restricted cubic spline showed no non-linear associations between total somatic symptoms with remission (P-value for non-linear = 0.238). Pain, autonomic, and CNS symptoms showed similar results. Sex-stratified analysis showed that total somatic symptoms, pain symptoms, and autonomic symptoms were negatively correlated with remission in females, whereas CNS symptoms were negatively associated with remission in males. Our findings indicate that specific somatic symptoms exert differential effects on remission of MDD. Therapeutic interventions that target pain, autonomic, and CNS symptoms may increase the probability of remission. Furthermore, interventions for somatic symptoms should be tailored by sex, and females deserve more attention.