Social factors and the psychobiology of depression: Relations between life stress and rapid eye movement sleep latency.

Both stress and REM latency were associated with greater severity of self-reported depressive symptoms and alternative explanations of these findings are discussed, with particular emphasis on different roles of pre-onset and post-ONSet stressors.

Abstract

We examined psychosocial factors (i.e., life stress) and biological factors (i.e., REM sleep latency) that are hypothesized to be of complementary importance for defining depressive subtypes in a sample of 61 nonpsychotic, endogenous major depressives. Subjects were evaluated on several diagnostic scales for life stress, on electroencephalographic sleep data, and on 2 symptom measures for depression. As predicted, persons with severe stress that occurred shortly before depression onset had essentially normal REM latency values; patients without such stress had reduced REM latency values. Both stress and REM latency were also associated with greater severity of self-reported depressive symptoms. Alternative explanations of these findings are discussed, with particular emphasis on different roles of pre-onset and post-onset stressors.