Suicide attempters and substance users form heterogeneous populations (e.g. Epstein et al. 2002; Goldston et al. 1998; Pfeffer et al. 1983; Walrath et al. 2001) with different risk and protective factors existing within subgroups of suicidal or drug-using individuals (Epstein et al. 2002; Goldston et al. 1996, 1998; Mandell et al. 2006; Walrath et al. 2001). Previous efforts to distinguish or characterize groups have generally focused on suicidal behavior or substance use behavior at a single time point, such as time-of-treatment. However, an individual’s substance use or suicidal behavior may change over time. Research is needed to characterize different developmental trajectories of suicidal and substance use and the risk and protective factors associated with these different trajectories.
