Depression and the association of smoking and suicide

Influence of demographic factors and serotonin transporter-linked polymorphic region (5-HTTLPR) variants on major depression in a northeastern Thai population

Background: Several lines of evidence suggest that the serotonergic system may be involved in the etiology of major depressive disorder (MDD). Objective: Investigate a potential association between the functional polymorphism in the serotonin transporter-linked polymorphic region (5-HTTLPR) and MDD in a northeastern Thai population, and explore the involvement of demographic characteristics in this disorder. Methods: One hundred eighty seven patients with MDD and 207 healthy controls were recruited from the same geographical area into the study. The 5-HTTLPR genotypes were determined using polymerase chain reaction (PCR) and analyzed statically. Results: Significant demographic differences between the two groups were observed, which included age, marital status, occupation, educational background, income, and alcohol use. The allele frequencies of the 5- HTTLPR polymorphism in our studied population were relatively near those of Asian populations, especially Chinese, which was regarded as enormously distinct from those of Caucasians. Nevertheless, our present study found no significant association between this polymorphism and MDD with respect to either genotype distributions or allele frequencies. Conclusion: No involvement of the 5-HTTLPR polymorphism was suggested, but demographic features in MDD were highlighted with respect to this studied population.

Increased risk of suicidal ideation in smokers and former smokers compared to never smokers: evidence from the Baltimore ECA follow-up study

The incidence rate of suicidal ideation among current and former smokers versus never smokers is not known. In this study, the age-adjusted incidence of suicidal ideation was highest among current smokers, followed by former, then never smokers. The adjusted hazard for suicide ideation was 2.22 (95%CI = 1.48, 3.33) and 1.19 (95%CI = 0.78, 1.82) for current and former smokers, respectively, compared to never smokers. Results indicate that current smokers have increased risks of suicidal ideation above and beyond the risk for never and former smokers regardless of age, gender, history of depressive disorder or anxiety symptoms, and alcohol abuse/dependence. Smoking cessation might be beneficial for some suicide prevention efforts.

Belief in the inevitability of suicide: results from a national survey

To examine public opinion regarding the effectiveness of means restriction as an approach to preventing suicide we asked a national sample of 2,770 respondents a hypothetical question about what effect a suicide barrier might have had on the ultimate fate of the more than 1,000 people who have jumped to their death from the Golden Gate Bridge. Thirty-four percent of respondents believed that every single jumper would have found another way to complete suicide and an additional 40% believed that "most" would have completed suicide using other means. The strongest predictors of belief in complete substitution were firearm ownership and cigarette smoking. Belief in the inevitability of suicide may be a political impediment to adopting potentially effective suicide prevention efforts.