Neurobiological research on sleep and stress hormones in epidemiological samples.

Information on stress hormones and sleep disturbance in posttraumatic stress disorder (PTSD) is on the basis of clinical samples and samples of other selective populations. Neurobiological studies nested in a large epidemiological community sample were recently reported. PTSD was compared with several control groups, defined by exposure and by diagnostic classification on the basis of comorbidity with Major Depression. Key findings were: (a) higher mean catecholamines in persons with PTSD versus controls; (b) no difference in mean cortisol between groups; (c) comorbid PTSD and depression was associated with higher cortisol in women; and (d) polysomnographic studies failed to detect clinically relevant sleep disturbance in PTSD, although an increase in brief arousal from REM was detected. Methodological questions raised by discrepancies between biological findings from epidemiologic versus clinical and other selective samples are discussed.