In a sample enriched for familial liability to substance use, particularly alcohol dependence, we find support for associations between substance involvement, SI and SA. When examined using cross-sectional approaches, these associations were significant and positive, ranging from 1.42 (SI and alcohol use) to 4.42 (SA and alcohol use), and were robust to the inclusion of covariates. These findings suggest that, across the lifetime, substance involvement and suicidal thoughts and behaviors are, somewhat independently, associated. These results are highly consistent with several studies, and in particular, with two recent meta-analyses for alcohol use disorders and tobacco smoking. The first meta-analysis (Darvishi et al., 2015) of 420,732 participants concluded that alcohol use disorders were associated with suicidal ideation (OR = 1.86), attempt (OR = 3.13) and completion (OR = 2.59). The second (Poorolajal and Darvishi, 2016) identified 63 studies on the relationship between current smoking and suicide (N=8,063,634) and found significant associations for suicidal ideation, plan, attempt and completion (OR > 2.0). These findings also support results from another meta-analysis which suggests that chronic, but not acute, cannabis use is associated with suicidal ideation and attempt (Borges et al., 2016).
