Smoking as "independent" risk factor for suicide: illustration of an artifact from observational epidemiology?

doi:10.1016/0140-6736(92)92242-8

The Lancet

Volume 340, Issue 8821, 19 September 1992, Pages 709-712

https://doi.org/10.1016/0140-6736(92)92242-8 Get rights and content

Abstract

Two widely used criteria for determining whether an association between a risk factor and a disease is causal are dose response and independence from other factors. Data from a large US risk factor study (MRFIT) throw up a relation between cigarette smoking and suicide that meets these criteria, yet appears to be biologically implausible. It is likely that many more such associations, for other exposures and other diseases, are equally spurious, but are protected by their lack of obvious implausibility.

References (38)

Je Manson et al.
Physical activity and incidence of non-insulin dependent diabetes mellitus in women
Lancet
(1991)
Djp Barker et al.
Weight in infancy and death from ischaemic heart disease
Lancet
(1989)
Eb Rimm et al.
Prospective study of alcohol consumption and risk of coronary disease in man
Lancet
(1991)
Rk Ross et al.
A prospective study of risk factors for traumatic deaths in a retirement community
Prev Med
(1990)
M. Marmor et al.
Risk factors for Kaposi's sarcoma in homosexual man
Lancet
(1982)
An Phillips et al.
How independent are "independent" effects? Relative risk estimation when correlated exposures are measured imprecisely
J Clin Epidemiol
(1991)
Pn Hopkins et al.
Identification and relative weight of cardiovascular risk factors
Cardiol Clin
(1986)
Ar Feinstein
Scientific standards in epidemiological studies of the menace of daily life
Science
(1988)
Mj Thun et al.
Aspirin use and reduced risk of fatal colon cancer
N Engl J Med
(1991)
Ml Slattery et al.
Cigarette smoking and exposure to passive smoke are risk factors for cervical cancer
JAMA
(1989)

Kj Mattila et al.

Assocation between dental health and myocardial infarction

BMJ

(1989)

A. Bradford Hill

The environment and disease: association of causation?

Proc R Soc Med

(1965)

Jd Neaton et al.

Recruitment of participants for the Multiple Risk Factor Intervention Trial (MRFIT)

Cont Clin Trials

(1987)

Jd Neaton et al.

Total and cardiovascular mortality in relation to cigarette smoking, serum cholesterol concentration, and diastolic blood pressure among black and white males followed for up to five years

Am Heart J

(1984)

Dr Cox

Regression models and life tables

J R Stat Soc B

(1972)

S. Stack

Suicide in Detroit 1975: changes and continuities

Suicide Life Threaten Behav

(1982)

N. Kreitman et al.

Association of age and social class with suicide among men in Great Britain

J Epidemiol Commun Health

(1991)

Eeh Griffith et al.

Recent trends in suicide and homicide among blacks

JAMA

(1989)

Cited by (145)

The effect of cigarette smoking on Vitamin D level and depression in male patients with acute ischemic stroke
2016, Comprehensive Psychiatry
The association between low vitamin D levels and depression has been well documented in nonstroke subjects. Accumulating evidence shows that low vitamin D levels may be also associated with depression post stroke. Cigarette smoking was associated with lower vitamin D levels. The purposes of this study were to compare vitamin D levels in smokers to nonsmokers and examine the association between vitamin D levels and depression symptoms in patients with acute ischemic stroke.
Serum levels of 25-hydroxyvitamin D [25(OH)D] were measured in 194 males within 24 h after admission: 116 smokers and 78 nonsmokers. Depression symptoms were assessed with the 17-item Hamilton Depression Scale (HAMD-17). Patients with the HAMD-17 score >7 were identified to have depression symptoms.
The chi-square test showed that the frequency of depression in the smoker group was 23.3% (27/116), which was significantly higher than that in the nonsmoker group (11.5% = 9/78), with an odds ratios (OR) of 2.33 (95% CI: 1.03–5.27; χ² = 4.25, df = 1, p = 0.039, φ = 0.15). Vitamin D levels were significantly lower in smokers than in nonsmokers (52.4 ± 20.8 vs 61.7 ± 19.2; F = 9.88, p = 0.002), with an effect size of 0.05 (η_p²). Patients with depression symptoms showed lower vitamin D levels than those with no depression symptoms (49.2 ± 19.6 vs 57.7 ± 20.6; F = 5.03, p = 0.03), with an effect size of 0.03 (η_p²).
Higher rates of depression in smokers with acute ischemic stroke may be associated with lower vitamin D levels induced by smoking.
Smoking and suicidality in patients with a psychotic disorder
2014, Psychiatry Research
Cigarette smoking has been associated with an increased risk of suicide. Patients with psychosis are more likely to smoke cigarettes and are also at an increased risk of suicide. The aim of this study was to compare risk for suicidal behavior among patients with psychosis who were current smokers, previous smokers and nonsmokers. We studied 1812 of the 1825 participants who took part in the Australian Survey of High Impact Psychosis (SHIP) for whom smoking data was available. We identified predictors for lifetime suicide attempts using univariate logistic regression analysis. These variables were retained for the multiple logistic regression models if they were a significant predictor of lifetime suicide attempts. A series of multiple logistic regressions were then conducted to predict lifetime suicide attempts using current smoking status and lifetime smoking status as independent variables, respectively, while controlling for the retained predictor variables. Current smoking and lifetime smoking were statistically significant predictors of lifetime suicide attempts. However adding the covariates to a logistic regression model reduced this association to non-significance. The strongest predictors were self-harm in the past 12 months, the presence of lifetime depressive symptoms and a diagnosis of psychotic depression. Identification of suicide risk factors is essential for successful suicide prevention. While previous research highlights the importance of cigarette smoking as an important risk factor for suicidal behaviors including in patients with psychosis, these results must be interpreted within the context of methodological issues.
Causal inference with observational data: The need for triangulation of evidence
2021, Psychological Medicine
Examining the effect of smoking on suicidal ideation and attempts: Triangulation of epidemiological approaches
2020, British Journal of Psychiatry
Association of genetic liability to smoking initiation with e-cigarette use in young adults: A cohort study
2023, Advances in Surgical and Medical Specialties
Growing Evidence for a Causal Role for Smoking in Mental Health
2022, Nicotine and Tobacco Research

View all citing articles on Scopus

View full text

EPIDEMIOLOGYSmoking as "independent" risk factor for suicide: illustration of an artifact from observational epidemiology?

Abstract

Lancet

Lancet

Lancet

Prev Med

Lancet

J Clin Epidemiol

Cardiol Clin

Scientific standards in epidemiological studies of the menace of daily life

Science

Aspirin use and reduced risk of fatal colon cancer

N Engl J Med

Cigarette smoking and exposure to passive smoke are risk factors for cervical cancer

JAMA

Assocation between dental health and myocardial infarction

BMJ

The environment and disease: association of causation?

Proc R Soc Med

Recruitment of participants for the Multiple Risk Factor Intervention Trial (MRFIT)

Cont Clin Trials

Total and cardiovascular mortality in relation to cigarette smoking, serum cholesterol concentration, and diastolic blood pressure among black and white males followed for up to five years

Am Heart J

Regression models and life tables

J R Stat Soc B

Suicide in Detroit 1975: changes and continuities

Suicide Life Threaten Behav

Association of age and social class with suicide among men in Great Britain

J Epidemiol Commun Health

Recent trends in suicide and homicide among blacks

JAMA

EPIDEMIOLOGY
Smoking as "independent" risk factor for suicide: illustration of an artifact from observational epidemiology?