Abstract
OBJECTIVE: Chronic pain and depression are frequent conditions in primary care patients. Depression is frequently overlooked in the presence of pain of uncertain origin. The aim is to measure the prevalence and clinical correlates of unrecognized comorbid mood disorders and chronic pain of uncertain origin in older primary care patients, and to elucidate the differences with younger adults with the same conditions. DESIGN: Cross-sectional study. SETTING: Primary care centres in Spain. PARTICIPANTS: Patients (n= 2720) with persistent pain of uncertain origin. MEASUREMENTS: Pain characteristics, sites and intensity (Visual Analogical Scales), depression (PRIME-MD interview), clinical characteristics and health services use. RESULTS: We observed a similarly high (80.5%) prevalence of undiagnosed mood disorders (especially major depressive disorders) among older and younger adult patients with comorbid chronic pain complaints of uncertain origin. Older patients suffered pain that was more intense, longer lasting and located in a higher number of different areas, when compared to younger patients. Pain intensity was a factor associated with suffering from mood disorders among patients above 65 years, whilst the number of pain sites was a more important factor among younger patients. CONCLUSIONS: Depression is highly associated with pain of uncertain origin in older patients with differences in pain characteristics when compared to younger patients. The robust comorbid relationship between both conditions should alert clinicians to specifically look for depression in the presence of poorly explained painful symptoms.