Cigarettes and suicide: a prospective study of 50,000 men

Abstract

A B S T R A C TObjectives. This study examined the relation between smoking and suicide, controlling for various confounders.Methods. More than 50 000 predominantly White, middle-aged and elderly male health professionals were followed up prospectively with biennial questionnaires from 1986 through 1994. The primary end point was suicide. Characteristics controlled for included age, marital status, body mass index, physical activity, alcohol intake, coffee consumption, and history of cancer.Results. Eighty-two members of the cohort committed suicide during the 8-year follow-up period. In age-adjusted analyses with never smokers as the comparison group, the relative risk of suicide was 1.4 (95% confidence interval [CI] = 0.8, 2.3) among former smokers, 2.6 (95% CI = 0.9, 7.5) for light smokers (<15 cigarettes/day), and 4.5 (95% CI = 2.3, 8.8) among heavier smokers. After adjustment for potential confounders, the relative risks were 1.4 (95% CI = 0.9, 2.4), 2.5 (95% CI = 0.9, 7.3), and 4.3 (95% CI = 2.2, 8.5), respectively.Conclusion. We found a positive, dose-related association between smoking and suicide among White men. Although inference about causality is not justified, our findings indicate that the smoking-suicide connection is not entirely due to the greater tendency among smokers to be unmarried, to be seden- 1 Although the nature of the relation between cigarette smoking and disease has been most convincingly demonstrated for physical illness, several researchers have linked smoking to mental illness, especially depression. 2-14Almost a dozen studies have shown a significant association between smoking and suicide. However, many of these studies were small and did not control for characteristics common to both smokers and persons who commit suicide.13,15-25 For example, only 2 prospective studies with more than 20 suicides controlled for alcohol intake-and these yielded conflicting results. 18,22 In this article, we present data on more than 50 000 men followed up prospectively for 8 years. Our analysis controlled for several potentially important behavioral, situational, and demographic factors that have been identified in the suicide, smoking, and depression literature. In addition, the investigation evaluated the relation between suicide and smoking, while taking into account changes in smoking status during follow-up. The study also examined prospectively the contribution of developing cancer to the association between smoking and suicide.

Cigarette smoking and completed suicide: Results from 3 prospective cohorts of American adults

“…2000; Breslau et al 2005; Yaworski et al 2011) but other have not (Hemmingsson and Kriebel 2003; Kessler et al 2007; Boden et al 2008). However, two of these studies were cross-sectional (Kessler et al 2007; Yaworski et al 2011) and most of the prospective cohorts did not adjust for psychiatric disorders (Hemenway et al 1993; Tverdal et al 1993; Doll et al 1994; Leistikow et al 2000; Miller et al 2000a; Miller et al 2000b; Iwasaki et al 2005). Even if several cohort studies have found a positive monotonic association between cigarette smoking and suicide or suicidal behavior, smoking was assessed only at the cohort inception and not updated during the follow-up.…”

“…We therefore accessed data from three large U.S. cohorts in which cigarette smoking was assessed every two years to investigate prospectively and over a long follow-up period the association between smoking and quitting smoking and risk of deaths from suicide. The present work represents an extension of a previous brief report in the NHS (Hemenway et al 1993) and a report based on only 8 years of follow-up in the HPFS (Miller et al. 2000b).…”

“…Smoking as a risk factor for suicide has been proposed by cohort studies that found a positive association between cigarette smoking and suicide or suicidal behaviors (Hemenway et al 1993; Tverdal et al 1993; Doll et al 1994; Miller et al 2000a; Miller et al 2000b; Tanskanen et al 2000; Breslau et al 2005; Iwasaki et al 2005; Yaworski et al 2011). However, this relationship is controversial and the explanations for this association remain unclear (Hughes 2008).…”

Social Integration and Suicide Mortality Among Men: 24-Year Cohort Study of U.S. Health Professionals

“…The time scale for the analysis was then measured in months since the start of the current questionnaire cycle. We also adjusted our estimates for baseline occupational category (27, 28) and the following time-updated variables: employment status (29); smoking status (30); alcohol intake (31); caffeine intake (32); antidepressant medication use (13, 33); body mass index (34, 35); self-report of a routine physical examination within the previous 2 years; weekly physical activity (36); and history of hypertension, diabetes, hypercholesterolemia, or renal failure (37, 38). To evaluate for departures from the proportional hazards assumption, we used likelihood ratio tests comparing models with and without the interaction terms of age by the specific exposures of interest.…”

Suicides, Homicides, Accidents, and Other External Causes of Death among Blacks and Whites in the Southern Community Cohort Study

“…Current cigarette smoking was associated with about a two-fold relative risk for suicide in SCCS participants. Perhaps no risk factor for suicide has been examined more extensively than cigarette smoking, and a direct relation between smoking and suicide has been observed in most studies [9] – [14] . The explanation for the association between cigarette smoking and suicide risk is unknown; it has been suggested that cigarette smoking may be a marker for stress or psychiatric problems, and residual confounding with alcohol or drug abuse is possible, but a direct role of cigarette smoking on brain levels of serotonin or monoamine oxidases has not been ruled out [10] , [14] , [29] .…”