Bright light blocks amitriptyline-induced cholinoceptor supersensitivity.

Introduction thal et al., 1984). This syndrome reportedly Seasonal affective disorder (SAD) is a synresponds to daily treatment with 2-6 hr of drome marked by recurrent depressions that bright artificial light (Lewy et al. 1982; Rogenerally occur in the fall or winter (Rosensenthal et al. 1984, 1986; James et al. 1985; Wehr et al. 1986). Neurobiological mechanisms accounting for the efficacy of this treatment remain unknown. Certain forms of afDepartments of Psychiatry (S.C.D., D.F.) and Neuroscience (S.C.D.), Ohio State University, Columbus, OH; and the fective illness may involve state-independent Department of Psychiatty (M.J.M), University of Michigan, Desupersensitivity of central muscarinic mechatrait, Ml. Address reprint requests to: Dr. Steven C. Dilsaver, Departments nisms (Janowsky et al. 1972; Dilsaver 1986aof Psychiatry and Neuroscience, Ohio State University, 473 West c). Amitriptyline and other heterocyclic anti12th Avenue. Columbus, OH 432101221. Supported in part by Physician Scientist Career Development Award depressants produce supersensitivity of a cen(Muscarinic Receptor Abnormalities in Affective Illness) SRCKl 1 tral muscarinic mechanism involved in the MHOO553-02, NIH Grant 2507 RR0583-5, the State of Ohio Neuroscience Program, and the Bremer Foundation. regulation of core temperature (Dilsaver et al.