Brief Reports BIOL PSYCHIATRY 1485 1987:22:1481-1485 test of olfactory function. Physiol Behav 32:498- histories of non-insulin dependent diabetes mel- 502. litus. Chem Senses 6:435-443. Hamilton M (1960): A rating scale for depression. J Neurol Neurosurg Psychiatry 23:56-62. Harris B, Young J, Hughes B (1984): Appetite and weight changes in patients presenting with de- pressive illness. .I AfSect Dis 6:331-339. Hopkinson G (1981): A neurochemical theory of ap- petite and weight changes in depressive states. Acta Psychiatr Stand 6412 1 l-225. Mezzich JE, Raab E (1980): Depressive symptom- atology across the Americas. Arch Gen Psychiatry 37:818-823. Settle RG (1986): Diabetes and chemical senses. In Meiselman HL, Rivlin R (eds), Clinical Mea- surement of Taste and Smell. New York: Mac- millan, pp 487-5 13. Steiner JE, Rosenthal-Zifroni A, Edelstein EL (1969): Taste perception in depressive illness. Israel Ann Psychiatry Rel Discip 71223-232. Paykel ES (1977): Depression and appetite. J Psy- chosom Res 2 1:40 l-407. Winokur A, Amsterdam JD, Maislin G (1985): Al- terations in glucose utilization and insulin secre- tion in depression. Annual Meeting of the Society of Biological Psychiatry, Dallas, Texas (abstr). Settle RG (1981): Suprathreshold glucose and fruc- tose sensitivity in individuals with different family Wright JH, Jacisin JJ, Radin NS, Bell RA (1978): Glucose metabolism in unipolar depression. Br J Psychiatry 132:386-393. Decrease in Core Temperature as an Indication of Cholinergic Overdrive during Amitriptyline Withdrawal Steven C. D&aver and Mark J. Majchrzak Introduction Dilsaver et al. (1983a,b, 1984) observed that the withdrawal of tricyclic antidepressants (TCAs) results in the development of an array of symp- toms that can be categorized to define four syn- dromes: (1) general somatic distress with flu- From the Mental Health Research Institute (S.C.D.). Department of Psychiatry (S.C.D.. M.J.M.), University of Michigan, Ann Ar- bor, MI Supported by Physician Scientist Career Development Award (Mus- carinic Receptor Abnormalities in Affective Illness) SRC IKI I MHO055302 and NIH 2507RR0538300025. Address reprint requests to Dr. S.C. Dilsaver. Depanment of Psy- chiatry, Division of Neuroscience, Ohio State University Col- lege of Medicine, Ohio State University, 473 West 12th Avenue, Columbus OH 43201.1228. Received March 10. 1987; revised May 11, 1987. 0 I987 Society of Biological Psychiatry like symptomatology, (2) excessive, vivid dreaming and initial, middle, and terminal in- somnia, (3) parkinsonism or akathisia, and (4) hypomania. The first three syndromes may be due to withdrawal-induced cholinergic ov- erdrive at peripheral and central sites. The hypothesis that TCA withdrawal pro- duces cholinergic overdrive is supported by re- ports that antimuscarinic agents produce toler- ance (Friedman et al. 1969), all TCAs block physiological (Dilsaver 1986) and biochemical responses mediated by muscarinic receptors (mAchRs) (Richelson and Dininetz-Romero 1977), and TCAs competitively displace mAchR receptor radioantagonists in vitro (Snyder and otJO6-3223/X7/$03 50