Tobacco smoking and bipolar disorder.
BACKGROUND
We sought to determine whether tobacco smoking is associated with bipolar disorder.


METHODS
This case-control study carried out in Alava, in the north of Spain, included patients with a DSM-III-R diagnosis of bipolar disorder type I (N = 51) and a representative sample of the normal population (N = 517). Smoking history of bipolar patients was assessed with the Fagerstrom Test for Nicotine Dependence and was verified by family members of the patients.


RESULTS
The frequencies of ever smoking and current daily smoking were, respectively, 63% (32/51) and 51% (26/51) for the bipolar patients and 45% (235/517) and 33% (169/517) for the control group (respective odds ratios [ORs] and 95% confidence intervals [CIs] were OR = 2.0, 95% CI = 1.1 to 3.8 and OR = 2.1, 95% CI = 1.2 to 4.0). The differences were significant (p = .03 and p = .042, respectively) for bipolar versus control males. Bipolar disorder (in both genders) was also significantly associated (OR = 4.4, 95% CI = 1.7 to 11.9, p = .0015) with heavy smoking (more than 1 pack per day).


CONCLUSIONS
Despite its small sample size, this study suggests that smoking may be more prevalent in bipolar patients than in the normal population. Since most patients started to smoke before the onset of illness, vulnerability to bipolar illness may make subjects vulnerable to become tobacco smokers.
Gonzalez-Pinto
A
A
Santiago Apostol Hospital, Vitoria, Alava, Spain.
Gutierrez
M
M
Ezcurra
J
J
Aizpuru
F
F
Mosquera
F
F
Lopez
P
P
de Leon
J
J
D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D000437:Alcoholism / Q000175:diagnosis / Q000453:epidemiology; D001714:Bipolar Disorder / Q000175:diagnosis / Q000453:epidemiology*; D016022:Case-Control Studies; D015897:Comorbidity; D016001:Confidence Intervals; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D015995:Prevalence; D011618:Psychotic Disorders / Q000175:diagnosis / Q000453:epidemiology; D012720:Severity of Illness Index; D012737:Sex Factors; D012907:Smoking / Q000453:epidemiology* / Q000523:psychology; D013030:Spain / Q000453:epidemiology; D019966:Substance-Related Disorders / Q000175:diagnosis / Q000453:epidemiology; D014029:Tobacco Use Disorder / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology