Examining the Three-Step Theory (3ST) of Suicide in a Prospective Study of Adult Psychiatric Inpatients

This study examined the validity and predictive utility of the three-step theory (3ST) of suicide in psychiatric patients. Participants were 190 consecutively admitted adult psychiatric inpatients (53% female, 60% White, ages 18–73) assessed at three time points: baseline, 4 weeks later (n = 112), and 3 months postdischarge (n = 102). Results were broadly supportive of the 3ST. First, at baseline, an interactive model of pain and hopelessness accounted for substantial variability in suicidal desire, even when controlling for depression and lifetime ideation. This result replicated in different genders and age ranges (i.e., 18–32 and 33–73). Further, pain and hopelessness were robust predictors of suicidal desire weeks and months into the future. Second, among those with pain and hopelessness, lower connectedness, as well as the extent to which pain exceeds connectedness, were robust predictors of higher suicidal desire. Last, a baseline measure of practical capability for suicide predicted suicide attempts both retrospectively and prospectively, even when controlling for lifetime ideation—however, dispositional and acquired contributors to capability were less predictive. Results support the validity and predictive utility of the 3ST, and suggest that the theory may have utility for guiding risk assessment and intervention.