The development of suicide ideation and attempts: An epidemiologic study of first graders followed into young adulthood
Studying community residing youths originally recruited for an intervention trial upon entry into first grade, this project sought to estimate risk of suicide ideation and attempts to young adulthood, with focus on those who used drugs before age 16, as compared to youths who used later in development or not at all. Standardized interview assessments in 1989-1994 were completed with 2311 youths age 8-15. Roughly 15 years after recruitment, our study team reassessed 1695, nearly 75% of the survivors (mean age = 21), finding 155 to have made suicide attempts (SA) and 218 with onset of depression-related suicide ideation (SI). We estimate relative risk (RR), from survival analysis and logistic regression models, to study early use of tobacco, alcohol, cannabis, and inhalants, with covariate adjustments for age, sex, race-ethnicity, and other pertinent covariates. Early-onset of cannabis use and inhalant use for females, but not for males, signaled modestly excess risk of suicide attempt (cannabis-associated RR = 1.9; p = 0.04; inhalant-associated RR = 2.2; p = 0.05). Early-onset of cannabis use by females (but not for males) signaled excess risk for suicide ideation (RR = 2.9; p = 0.006). Early-onset alcohol and tobacco use were not associated with later risk of SA or SI. In light of the relatively modest strength of association, the evidence may well reflect an underlying common diathesis or unmeasured prior confounding influences that link early-onset illegal drug use with later risk of these suicide-related events, rather than an influence of early-onset drug use per se.