Depressed pain patients differ from other depressed groups: examination of cognitive content in a sentence completion task

Abstract

Depression is a common feature of chronic pain, but there is limited research into the content and frequency of depressed cognitions in pain patients. A limitation of previous research is the failure to include non-pain depressed comparison groups. The present study used a sentence completion task to investigate the content of cognition in four groups of participants: with pain and concurrent depression, pain without depression, depression without pain, and with neither pain nor depression. One hundred and seventy two participants generated sentences to a set of predefined stems. Complete responses were coded by affective valence (negative, positive and neutral) and health-related content. As predicted, participants with depression (with and without pain) produced more negative responses than non-depressed participants (with and without pain); participants with pain (depressed and nondepressed) produced more health responses than those without pain (depressed and controls); participants with depression and pain produced more negative health responses than any other group. The strengths of the current study are in the inclusion of the depressed non-pain group, the use of a comprehensive coding scheme applied by two independent raters, and the presence of depression validated through a diagnostic interview. In contrast to depressed groups without pain, participants with pain and depression exhibit a cognitive bias specific to negative aspect of health. This focus facilitates understanding of the relationship between depression and pain processing: The implications for therapeutic interventions are discussed