Temporal dynamics of the wish to live and wish to die signal near-term increases in suicidal thinking in a veteran sample

Preventing suicide is challenging because there are no ways to reliably determine when someone is about transition from a lower to higher risk state. Dynamic interactions between the wish to live (WTL) and die (WTD) may differentiate higher from lower risk suicide states and signal near-term transitions of increasing risk. In this cohort design, clinical trial participants with posttraumatic stress disorder (PTSD) received prompts to complete a brief survey on their phone 4 times per day for 14 consecutive days at pseudorandom times. Participants were asked to rate their WTL, WTD, suicidal desire, and desire for self-preservation using 4 items from the Scale for Suicide Ideation (SSI). Participants were 116 military personnel and veterans diagnosed with PTSD (69.8 % male, 76.7 % White, M age = 47.2 ± 12.1 years). Multilevel dynamical systems modeling revealed that the WTL and WTD changed in coordinated and opposing directions except when suicidal desire was most severe and was about to worsen at the next time point. Under these conditions, WTL and WTD switched to an oscillatory pattern. Temporal patterns in WTL and WTD differ when people report lower versus higher risk suicidal states. Oscillations in WTL and WTD signal near-term worsening of suicidal desire. Multiple qualitatively distinct suicide risk states exist, suggesting suicide risk is categorical, not continuous.