The association of supersensitive cholinergic REM-induction and affective illness within pedigrees.

Based on the Rieder and Gershon (1978) biological genetic study paradigm we compared the prevalence of a putative vulnerability factor (rapid cholinergic REM sleep induction) between 35 affectively ill and 31 well first-degree relatives of 34 probands chosen on the basis of presence of primary affective illness and positive marker status. A significantly higher percentage of ill relatives (63%, 22 out of 35 subjects) had a supersensitive REM-induction response as compared to well relatives (22%, 7 out of 31 subjects). Since the current study does not rule out the effects of prior depressive episodes or treatment on cholinergic sensitivity, caution must be exercised in the interpretation of our findings.