WHAT DOES THE BDI MEASURE IN CHRONIC PAIN

The Beck Depression Inventory (BDI) has been widely used to document t he prevalence of depressive symptomatology in samples of chronic pain patients and as an outcome measure in studies of the psychological man agement of chronic pain. Several BDI items have a somatic content (sle ep disturbance, fatigue, etc). Since chronic pain may have similar som atic effects, the significance of the total BDI score in this populati on is unclear. Two hundred and forty mixed chronic pain patients compl eted the BDI at screening interview for a psychologically based pain m anagement programme; of these, 207 (mean age 50.1; years; 63% female) were later admitted to the programme when the BDI was readministered a long with measures of pain, anxiety, pain-related cognitions, and phys ical performance. The mean BDI score of the sample was 18.1, with 71.7 % meeting criteria (scoring 13 or more) for at least mild depression. A principal-components analysis of the BDI yielded 3 meaningful factor s labelled: sadness about health, self-reproach, and somatic disturban ce. Among the most frequently endorsed items were those loading on the somatic factor. The pattern of relationships between individual facto r scores and measures of pain, mood, cognition, and physical functioni ng indicated that the use of the total BDI score may give a misleading impression of the nature and degree of affective disturbance in this group of patients. The implications of these findings for our understa nding of BDI scores obtained by chronic pain patients are discussed.