There were no significant differences between models in Table 3 (offspring level selleck CHIR99021 covariates) and their respective models (offspring level and parental level covariates) in Tables 6 and and77 (Wald chi-square = 42.6, p = .21). Table 6. Association Between Male Offspring Regular Smoking, Nicotine Dependence, and Suicidal Behavior in Males Adjusted for Father and Mother Suicidea, Fatherb and Mother Nicotine Dependencecd, and Father and Mother Conduct Disorder and Adjusted for Offspring … Table 7. Association Between Female Offspring Regular Smoking, Nicotine Dependence, and Suicidal Behavior in Females Adjusted for Father and Mother Suicidea, Fatherb and Mother Nicotine Dependencecd, and Father and Mother Conduct Disorder and Adjusted for Offspring …

Discussion In unadjusted analysis, in a cohort of 1,919 male and female offspring, we observed that increasing involvement in smoking was associated with increasing suicidal behavior such that ever smoking was associated with ideation among females and with ideation + plan among males. Regular smoking was more strongly associated with this measure of suicidal behavior and was significantly associated with ideation + plan among males and with ideation + plan + attempt or ideation + attempt in females. Last, nicotine dependence increased in strength of association from ideation through ideation + plan + attempt or ideation + attempt. Adjustment for offspring covariates attenuated the association between smoking status and levels of suicidal behavior; however, adjustment for paternal and maternal familial vulnerability did not mediate the effect between smoking status and levels of suicidal behaviors.

The familial contributions to suicidal behavior as well as the familial contribution to smoking were controlled in the present study. Though we are unable to determine the temporal direction of effect in the present design, we can conclude that the association exists above and beyond familial contributions to smoking and suicidal behavior. We also found the association remained after controlling for offspring conduct disorder, major depression, alcohol abuse/dependence, and illicit drug abuse/dependence but were attenuated, suggesting partial mediation by AV-951 these offspring level variables. The present design provides some of the strongest evidence to date that ever smoking, regular smoking, and nicotine dependence are all independent correlates of suicidal behavior above the influence of familial vulnerability. Our results extend the growing literature that establishes the association between smoking and suicidal behaviors (Breslau et al., 2005; Clarke et al., 2010; Kessler et al., 2009).