290. PIP2 platelet membrane levels: a marker of relevance for the pathophysiology of bipolar disorder?

wave sleep (SWS) and a markedly increased REM sleep. Sleependocrine effects of acute and pulsatile injections of cortisol in healthy subjects include an increased SWS and profound suppressed REM sleep, as well as an elevated GH secretion. We now applied this paradigm in untreated depressive inpatients in order to investigate whether the cortisol injections improve the related sleep deficits during acute illness, and whether these effects are depending on the HPA function status assessed by the combined dexamethasone/corticotropin releasing hormone (DEX/ CRH)-test. All 8 patients underwent this test before spending 4 consecutive nights in the sleep laboratory: adaption, baseline (no cannulation), placebo and verum (with hourly administered hydrocortisone, 1 mg/kg BW, 7 P.M.–7 A.M.). Measured plasma levels of GH and cortisol showed an immediate increase in circulating GH (presleep peak) and in the second half of night. The sleep EEG, analyzed according to serial spectral analysis, revealed an enhanced delta activity, providing further evidence for a SWS promoting effect of acute cortisol administration. Interestingly, the effects on the EEG power spectrum seemed to be pronounced in the patients characterized as “suppressors” when compared to those showing a “non-suppression” status in the DEX/CRH-test. There is some evidence that the function of the HPA axis influences the effects of cortisol on the sleep-EEG.