Several studies and reviews have documented the high degree of comorbidity between depression and chronic pain. It was reported that chronic muscle pain is frequently accompanied by symptoms of depression. The purpose of this study was then to investigate the prevalence of major depression in chronic pain patients (CPP) with myofascial pain syndrome (MPS) and to investigate the relationship between some clinical parameters and level of depression, utilizing a healthy control group without MPS. The study group consisted of 77 MPS patients (65 female, 12 male) and 72 healthy volunteers (60 female, 12 male). The diagnosis of MPS was based on clinical characteristics, examination findings, and ruling out other diagnoses. Major depressive disorder was diagnosed by a psychiatrist utilizing DSM-IV criteria. Levels of depression were obtained from the Beck Depression Inventory (BDI). There was no significant difference between MPS patients and controls with respect to age and gender (P > 0.05). The mean age of the patients was 31.1 years (SD 9.8) and the mean age of controls was 29.7 years (SD 7.1). Major depression was more frequently found in CPPs with MPS (P < 0.001). BDI scores were higher in the MPS group than in controls (P < 0.001). There was a significant correlation between the severity of pain and depression level in patients with MPS (r = 0.654, P < 0.001). Major depression is found in MPS CPPs at a rate previously noted in the literature in mixed diagnoses CPPs. In addition, the severity of the depression may be related to perceived pain severity.
