Neuroendocrine and Clinical Characteristics of Major Depressed Patients Exhibiting Sleep-Onset REM

Background: Previous reports suggest an association between sleep-onset REM (SOREM) and some clinical characteristics in depressive illness such as age, psychosis, and depression severity. The present study is aimed at further investigating clinical and neuroendocrine correlates of SOREM, controlling for the age-related variability in clinical data. Methods: Thyroid-stimulating hormone response to thyrotropin-releasing hormone, postdexamethasone cortisol levels, and clinical characteristics of 25 major depressive (MD) patients exhibiting SOREM in at least one of three consecutive recording nights were compared to those of 25 age- and sex-matched MD patients with three REM latencies above 50 min. Results: SOREM patients experienced more affective episodes leading to hospitalization and a shorter duration of current episode than patients with three REM latencies above 50 min. No association between psychosis and SOREM could be demonstrated, and hypothalamic-pituitary-adrenal or -thyroid axis disturbances were not more prevalent in SOREM patients. Conclusions: Our results suggest that clinical history rather than cross-sectional clinical characteristics relates to the occurrence of SOREM in major depressed patients.