Higher rates of cigarette smoking in male adolescents before the onset of schizophrenia: a historical-prospective cohort study.
OBJECTIVE
The prevalence of cigarette smoking among schizophrenia patients is significantly higher than in the general population; this may reflect self-medication of symptoms and/or adverse effects of neuroleptics. The authors examined the prevalence of cigarette smoking in apparently healthy adolescents later hospitalized for schizophrenia.


METHODS
Each year, a random sample of male Israeli military recruits, who have been screened and found not to be suffering from major psychopathology, complete a smoking questionnaire. Through the Israeli National Psychiatric Hospitalization Case Registry, 14,248 of these adolescents were followed to determine later psychiatric hospitalization.


RESULTS
Of the 14,248 adolescents assessed, 4,052 (28.4%) reported smoking at least one cigarette a day. Over a 4-16-year follow-up, the prevalence of schizophrenia in the entire cohort was 0.3% (N=44). Smokers were at greater risk for later schizophrenia; the adjusted relative risk was 1.94, and the 95% confidence interval (CI) was 1.05-3.58. The number of cigarettes smoked was significantly associated with the risk for schizophrenia. Compared to nonsmokers, adolescents who smoked 1-9 cigarettes/day were 1.38 times (95% CI=0.48-4.00) as likely to be hospitalized later for schizophrenia, and adolescents who smoked 10 cigarettes/day or more were 2.28 times (95% CI=1.19-4.34) as likely; the latter difference was statistically significant.


CONCLUSIONS
Taken together with the existing data on abnormalities in nicotinic transmission in patients and their relatives, this higher prevalence of smoking in future schizophrenia patients, before the onset of their illness, might indicate that impaired nicotinic neurotransmission is involved in the pathophysiology of schizophrenia.
Weiser
Mark
M
Department of Psychiatry, Sheba Medical Center, Tel Hashomer 52621, Israel.
Reichenberg
Abraham
A
Grotto
Itamar
I
Yasvitzky
Ross
R
Rabinowitz
Jonathan
J
Lubin
Gad
G
Nahon
Daniella
D
Knobler
Haim Y
HY
Davidson
Michael
M
D000293:Adolescent; D000294:Adolescent Behavior / Q000523:psychology*; D000328:Adult; D015331:Cohort Studies; D016001:Confidence Intervals; D005500:Follow-Up Studies; D006760:Hospitalization; D006801:Humans; D007557:Israel / Q000453:epidemiology; D008297:Male; D009538:Nicotine / Q000493:pharmacokinetics; D015995:Prevalence; D011446:Prospective Studies; D012042:Registries; D012307:Risk Factors; D012559:Schizophrenia / Q000175:diagnosis / Q000453:epidemiology* / Q000378:metabolism; D012737:Sex Factors; D012907:Smoking / Q000453:epidemiology* / Q000523:psychology
D009538:Nicotine