VIENNA – Current or former cigarette smoking is strongly associated with an increased rate of prior suicide attempts among Hungarian psychiatric outpatients, Dr. Zoltán Rihmer reported at the annual congress of the European College of Neuropsychopharmacology.
This finding confirms a link between cigarette smoking and suicidal behavior that has been previously noted in large epidemiological studies conducted elsewhere, including Finland and the United States, said Dr. Rihmer of the Hungarian National Institute of Psychiatry and Neurology, Budapest.
“Cigarette smoking is very important. When I learned that cigarette smoking is an independent suicide risk factor, I changed my smoking habit. I stopped smoking cigarettes and started smoking a pipe,” he quipped.
He and his colleagues interviewed 334 consecutive outpatients with unipolar major depression; bipolar disorder; panic disorder with no history of major depression; schizoaffective disorder; or schizophrenia as to their smoking habits and prior suicide attempts. Of these, 53% were current cigarette smokers and another 15% were ex-smokers. Not a single patient was primarily a pipe or cigar smoker or used smokeless tobacco.
In all, 37% of subjects had made one or more medically documented suicide attempts. The rate was 48% among current smokers, 43% in ex-smokers, and 25% in never-smokers. With the exception of patients with panic disorder (of whom only 3 of 60 reported a prior suicide attempt), the prevalence of prior suicide attempts was substantial among patients in all of the other diagnostic categories, ranging from 32% among all patients with bipolar disorder to 53% in those with unipolar depression.
A limitation of this study was that the results weren't adjusted for potential confounding variables, such as alcohol and caffeine consumption, age, and socioeconomic status, Dr. Rihmer noted.
The Hungarian findings, however, are consistent with a Finnish study that did adjust for potential confounders. In that study, the adjusted probability of one or more prior suicide attempts for 1,217 psychiatric inpatients was twice as great in current smokers as in nonsmokers. Smokers also had a 43% increased likelihood of suicidal ideation (Am. J. Psychiatry 1998;155:129–30).
In a separate population-based study involving nearly 37,000 Finns followed for a mean of 14.4 years, investigators found that the adjusted relative risks of both violent and nonviolent suicide increased in linear fashion with the number of cigarettes smoked per day (Acta Psychiat. Scand. 2000;101:243–5).
In the United States, Dr. Matthew Miller and his associates at the Harvard School of Public Health, Boston, reported an adjusted 1.4-fold increased risk of suicide among smokers of fewer than 15 cigarettes a day, and a 2.5-fold increased risk among heavier smokers, in the Health Professionals Follow-up Study, involving more than 51,000 predominantly white middle-aged and elderly men followed prospectively for 8 years (Am. J. Public Health 2000;90:768–73).
In a separate prospective cohort study involving 300,000 male U.S. Army soldiers followed for more than 960,000 person-years, Dr. Miller and his colleagues found that those who smoked more than 20 cigarettes a day were more than twice as likely to commit suicide as were never-smokers (Am. J. Epidemiol. 2000;151:1060–3).
Possible explanations for the strong link between smoking and suicidal behavior include a suggested association between smoking and aggressive-impulsive personality traits and high levels of sensation-seeking, according to Dr. Rihmer. This, in turn, has been related to reduced central serotonin function.
Hungary has historically had one of the world's highest suicide rates. The rate, however, has steadily dropped from 46 per 100,000 in 1984 to half that today, even though the collapse of the Soviet bloc in the early 1990s brought a sixfold jump in Hungarian unemployment, a 25% rise in diagnosed alcoholism, and a sharp increase in divorce.
The reduction in suicides despite this adverse backdrop has been attributed to substantial increases in the number of Hungarian psychiatrists, outpatient psychiatric clinics, and telephone hotlines, he said.
'I changed my smoking habit. I stopped smoking cigarettes and started smokinga pipe.' DR. RIHMER