Background: Chronic musculoskeletal pain (CMP) is associated with psychological distress and long-term disability. Underlying diagnoses causing long-term sickness absence due to CMP have not been explored enough. In a somatic health care setting, it is important to identify mental health comorbidity to facilitate the selection of appropriate treatment. The objectives of this study were to compare the scores of depressed mood obtained on the Beck Depression Inventory (BDI) with the diagnosis of depression made by a psychiatrist, and to study the prevalence of undiagnosed mental health comorbidity in these patients.
Methods and patients: 83 consecutive patients on sick leave (mean duration 21 months) due to CMP who had been referred by the Social Insurance Office to an orthopedist and a psychiatrist for assessment of the patient's diagnoses and capacity to work. The mean age was 45 (23-61) years, 58% were women and 52% were immigrants. The accuracy of measurements was calculated using the Diagnostic Statistical Manual of Mental Disorders IV as the Gold standard.
Results: Psychiatric illness was diagnosed in 87% of the patients. The diagnosis was depression in 56%, other psychiatric illnesses in 31%, whereas 13% were mentally healthy. Of all the patients, only 10% had a previous psychiatric diagnosis. The median value of the BDI score was 26 points in depressed patients, whereas it was 23 in patients with other psychiatric diagnoses. The sensitivity of the BDI to detect depression was 87.5%. We found good agreement between the BDI score and a diagnosis of depression.
Conclusion: Undiagnosed psychiatric disorders were commonly seen in patients with CMP. The high sensitivity of the BDI scores enables the screening of mental health comorbidity in patients with a somatic dysfunction. The test is a useful tool for detecting distress in patients who are on long-term sick leave due to CMP and who need additional treatment.
Keywords: agreement; disability; underlying diagnoses.