Pharmacology Blochem:stry &Behavtor, Vol 34, pp 149-155 ©PergamonPress plc, 1989 Pnnted m the U S A 0091-3057/89 $3 00 + 00 Smoking History, Instructions and the Effects of Nicotine: Two Pilot Studies JOHN R. HUGHES,~ GAIL STRICKLER, DAVID KING, STEPHEN T. HIGGINS, JAMES W. FENWICK, SUZY B. GULLIVER AND GINA MIREAULT Human Behavioral Pharmacology Laboratory Departments of Psychiatry, Psychology and Medical Biostatlstws Universlty of Vermont, Burlington, VT 05405 Received 16 May 1988 HUGHES, J R, G STRICKLER, D KING, S T HIGGINS, J W FENWICK, S B GULLWER AND G MIREAULT Smokang htstory, mstrucnons and the effects of nwonne Two pdot studws PHARMACOL BIOCHEM BEHAV 34(1) 149-155, 1989 --In Study 1, ten never-smokers, ten ex-smokers and rune current smokers received mcotme (2 nag) and placebo gum hourly for 4 hours on 2 consecutwe days m a randormzed, double-blind, cross-over protocol Dysphona from mcotme was greatest m never-smokers, intermediate m ex-smokers, and least in current smokers (p<0 05) On the thtrd day, subJeCtswere given concurrent access to the same gums and told to chew ad hb Across all subjeCts, mcotme was an averslve stmaulus 0 e, self-adrmmstered less than placebo) Nlcolane was avoided most m never-smokers, intermediate m ex-smokers and least in current smokers (p<0 05) Study 2 used a sumlar protocol and compared the nine current smokers m Study 1 who were not told they would receive mcotme with eight informed smokers, ~ e, smokers told they would receive mcotane Although mcotlne appeared to be a reinforcer more often in the reformed smokers than in the uninformed smokers (63% vs 22%), tlus result was not statastacally significant Our results suggest 1) past drug lustory can influence the stimulus effects of mcotme and 2) the effects of instructions on the response to mcotme may be less m experimental settangs than in therapeutac settangs Drug bastory Drug self-adnumstrataon Expectancy Instructions Nlcotane Smolong Remforcement Tobacco Tolerance SEVERAL factors control the stimulus effects of mcotme (3, 6, 11). Tb_ls aracle reports studies of the effect of past and present smoking history (Study 1) and instructions (Study 2) on the physiological and subjectave responses to and preference for mcotine and placebo in humans. STUDY 1 EFFECT OF PAST SMOKING HISTORY Past and present drug htstory influences the response to several drugs (38). In nonhumans, prior exposure to mcotme can produce tolerance to mcottmc effects many weeks later (28, 30, 35, 36) In humans, present smoking influences the response to mcotme; e g, smokers and nonsmokers differ m their heart rate response to nicotine (25). The effect of past smoking history, 1.e., comparing the effect of mcotlne between never-smokers and ex-smokers, has not been studied in humans. METHOD Sub lects Subjects were recruited by advertisements which stated, "Gum chewers wanted for a study on the use of gums to dehver medications " To be included, subjects must have chewed gum at least weekly and had never chewed mcotine gum. Subjects who had a history of psychiatric or drug abuse problems, might be pregnant or had a contraindication to mcotme gum (22) were excluded Potential subjects were asked about their present and past alcohol, tobacco, caffeine and drug use to minimize their knowing that they were &vlded into groups by smoking status alone Ten never-smokers (NS) and ten ex-smokers (ES) were chosen from the ehgthle subjects NS had never smoked daffy for >2 weeks. ES had smoked >10 cigarettes/day for >1 year and had been abstinent for >1 year. Nine current smokers (CS) served as a control group (one CS dropped out at the start of the expenment) Current smokers presently smoked >10 cigarettes/day for >1 year To prevent confoundmg the effects of the expenmenter- dehvered mcotme via mcotme gum and subject-dehvered mcotme via tobacco, CS were required to abstain from smoking overmght. Smoking status among the groups was confirmed at the first session by breath carbon monoxide (17) Subjects were unaware tRequests for reprints should be addressed to John R Hughes, Human Behavioral Pharmacology Laboratory, Department of Psycbaatry, Umverslty of Vermont, Burlington VT 05405 149