Sexually Dimorphic Effects of GHRH on
Sleep-Endocrine Activity in Patients with
Depression and Normal Controls - Part I: The Sleep
EEG
Irina A. Antonijevic, Harald Murck, Ralf-Michael Frieboes, Jens Barthelmes and Axel Steiger
Max Planc Institute of Psychiatry, Department of Psychiatry,
Munich D-80804, Germany
ABSTRACT
In patients with depression, enhanced secretion
of ACTH and cortisol, a reduction in slow wave
sleep (SWS) and a blunted nocturnal growth
hormone (GH) surge have been described and
attributed, at least partly, to an elevation of
corticotropin-releasing hormone (CRH), hence a
shift in the ratio between growth
hormone-releasing hormone (GHRH) and CRH.
We investigated the effects of pulsatile
administration of GHRH (4x50 µg, at hourly
intervals between 2200 and 0100 h) on the sleep
EEG (2300-0700 h) in patients with depression
(16 females, 19 males, age range 19-76 years)
and matched controls (20 females, 20 males). In
patients compared with controls, NREM sleep
and in particular stage 2 sleep was greatly
decreased at baseline. GHRH treatment
enhanced NREM sleep, and in particular stage 2
sleep in men, regardless of diagnosis, while
decreasing it in women (F=6.0 and 7.1,
p<0.05). In controls, aging was associated with
a decrease in NREM sleep, including both SWS
and stage 2 sleep (r= -0.45 r= -0.39,
p<0.05), while in patients only SWS declined
with age (r= -0.49, p<0.05). The significant
decrease in NREM sleep including stage 2 sleep in
patients with depression and elderly control
subjects is compatible with the suggested role of
sleep continuity and stage 2 sleep in cognitive
functioning. GHRH promoted NREM sleep, stage
2 sleep and sleep continuity and might prove
beneficial for improvement of cognitive function,
at least in men. These data support the
hypothesis that female gender, aging and
depression are associated with a shift in the
GHRH/CRH ratio towards CRH.