This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Hemmingsson, T. Articles by Lundberg, I. Search for Related Content PubMed PubMed Citation Articles by Hemmingsson, T. Articles by Lundberg, I. Related Collections Social Class Other Epidemiology Cognitive Functioning Substance Abuse

How Does IQ Affect Onset of Smoking and Cessation of Smoking—Linking the Swedish 1969 Conscription Cohort to the Swedish Survey of Living Conditions

From the Department of Public Health Sciences, Division of Social Medicine (T.H., P.A.); Department of Clinical Neuroscience, Division of Psychology, Karolinska Institute, Stockholm, Sweden (B.M.); School of Health & Environment, University of Massachusetts Lowell, Lowell, Massachusetts (D.K.); and Department of Medical Sciences, Occupational and Environmental Medicine, Uppsala University, Uppsala, Sweden (I.L.).

Address correspondence and reprint requests to Tomas Hemmingsson, PhD, Department of Public Health Sciences, Division of Social Medicine, Karolinska Institute, Norrbacka, 171 76 Stockholm, Sweden. E-mail: tomas.hemmingsson{at}ki.se

Objective: To examine the association between intelligence quotient (IQ) measured at ages 18 to 20 and onset of smoking, and the association between IQ and smoking cessation.

Methods: Data on IQ, smoking, mental health, and social background among 49,321 Swedish men born 1949 to 51, collected at conscription for military service in 1969, were used. The association between IQ and smoking cessation was investigated among those 694 members of the full cohort also interviewed in the Swedish Level of Living Conditions study 1981 to 2002.

Results: Lower IQ measured at ages 18 to 20 was weakly associated with increased prevalence of smoking, independently of indicators of mental illness and social misbehavior measured in late adolescence. By contrast, smoking cessation later in life among those who smoked at ages 18 to 20 was not associated with IQ. Among smokers, lower IQ was significantly associated with a lower level of smoking after adjusting for other factors.

Conclusion: Low IQ was associated with an increased prevalence of smoking in adolescence. However, the main part of this association disappeared after adjustment for measures of mental health and social function in early life. IQ was not associated with likelihood of quitting smoking.

Key Words: IQ • smoking • smoking cessation • mental health • social function

Abbreviations: IQ = intelligence quotient; CI = confidence interval; ICD-8 = International Classification of Diseases, 8th revision; ULF = Swedish Surveys of Living Conditions; OR = odds ratio.

This article has been cited by other articles:

				T Hemmingsson, B Melin, P Allebeck, and I Lundberg Cognitive ability in adolescence and mortality in middle age: a prospective life course study J Epidemiol Community Health, September 1, 2009; 63(9): 697 - 702. [Abstract] [Full Text] [PDF]

				M. Jokela, M. Elovainio, A. Singh-Manoux, and M. Kivimaki IQ, Socioeconomic Status, and Early Death: The US National Longitudinal Survey of Youth Psychosom Med, April 1, 2009; 71(3): 322 - 328. [Abstract] [Full Text] [PDF]