Trajectories of suicide ideation, nonsuicidal self-injury, and suicide attempts in a nonclinical sample of military personnel and veterans.

Nonsuicidal self-injury (NSSI) is a risk factor for suicide attempts, but little is known about NSSI among military personnel and veterans, or about the temporal sequencing of NSSI relative to suicide ideation and attempts. This study evaluates trajectories of suicide ideation, NSSI, and suicide attempts in a sample of 422 military personnel and veterans. Of those with a history of NSSI, 77% also experienced suicide ideation. Suicide ideation emerged before NSSI (67%) more often than the reverse (17%). Of those with a history of suicide attempt, 41% also engaged in NSSI. NSSI emerged prior to the first suicide attempt (91%) more often than the reverse (9%). The length of time from suicide ideation to suicide attempt was longer for those who first engaged in NSSI (median = 3.5 years) compared with those who did not engage in NSSI (median = 0.0 years), Wald χ(2)(1) = 11.985, p = .002. Age of onset was earlier for participants reporting NSSI only compared with those reporting both NSSI and suicide attempts (16.71 vs. 22.08 years), F(1, 45) = 4.149, p = .048. NSSI may serve as a "stepping stone" from suicide ideation to attempts for 41% of those who attempt suicide.