A DEVELOPMENTAL-APPROACH TO SEVERE DEPRESSION

Reduced rapid-eye-movement (REM) sleep latency and increased REM sleep activity are associated not only with increased risk of recurrent dep ressive episodes but also with shortened time to the onset of subseque nt episodes. Increased REM sleep activity might be a sign of attempt t o excite the photic-responsive brain regions during the night, and the re is a negative correlation between regional blood flow in the dorsol ateral prefrontal cortex and REM sleep. The relative deactivation of t he dorsolateral prefrontal cortex as a result of a developmental abnor mality could explain the increased REM sleep activity during the first half of the night and the subsequent terminal insomnia among depresse d subjects.