Effects of DSIP in man. Multifunctional psychophysiological properties besides induction of natural sleep.

Animal experiments confirmed the neuropeptide nature of delta-sleep-inducing-peptide (DSIP) and a species-specific sleep promotion. Five different human studies were carried out with single and repeated intravenous injections of DSIP under double-blind conditions, and with assessing treatment effects by psychophysiological tests and polygraphic recordings. Compatibility of DSIP was good. Slow injection proved essential. A latency of sleep induction of 1 h, but a duration of up to 20 h was found. The somnogenic properties, initially proven in animal studies, were confirmed. Indications of specific effects on chronobiological regulations were found. A complete normalization of disturbed sleep was achieved by four consecutive injections to insomniacs. During the active awake state, DSIP induced higher alertness and better performance. Psychological tests and evaluation by psychotherapists indicated modulation of ego functions by DSIP in the direction of improved stress tolerance and coping ability. The various actions of DSIP might be conceptualized neurophysiologically on the level of 'programming' behavior by means of changing 'local vigilances'. Whereas the somnogenic actions of DSIP appear promising for treating insomnia, other therapeutic perspectives in the field of psychiatry have to be explored.