A cross-sectional survey to investigate the prevalence of pain in Japanese patients with major depressive disorder and schizophrenia

We conducted a cross-sectional survey to assess the prevalence of physical pain in Japanese major depressive disorder (MDD) and schizophrenia (SZ) patients as well as in healthy controls (HCs). We also examined the association between their psychopathology and characteristics of pain according to a face-to-face survey by an experienced psychiatrist and psychologist. We analyzed 233 HCs, 94 MDD patients, and 75 SZ patients using the McGill Pain Questionnaire (MPQ) and SF-8 (all participants), the Hamilton Depression Rating Scale 21 items (MDD patients), and the Positive and Negative Symptom Scale (SZ patients). Although MDD patients experienced more pain than HCs, there was no difference in the prevalence of pain between SZ patients and HCs. Moreover, HCs with pain did not have higher SF-8 total scores than those without pain, whereas both MDD and SZ patients with pain had higher SF-8 total scores than those without pain. The severity of psychopathology in MDD and SZ patients was also positively associated with both the prevalence of pain and MPQ scores. MPQ scores were also associated with positive symptoms in SZ patients. Considering these results, physicians need to query MDD patients about physical pain during examination if they are to ensure a favorable and quick response to treatment. The severity of positive symptoms (i.e., clinical status) in SZ patients might also be associated with pain sensitivity, and warrants further investigation.