Suicide risk in a national VA sample: Roles of psychiatric diagnosis, behavior regulation, substance use, and smoking

Background: Most suicides are first attempts that are difficult to predict, possibly reflecting impaired and unstable behavior regulation. We sought to identify characteristics specifically associated with severe suicidal behavior by comparing risk ratios (RRs) for severe suicidal attempts (ATTP) to RRs for suicidal ideation (SI) only in a transdiagnostic sample of Veterans, focusing on impulsive-aggressive or externalizing behavior (EB), substance use disorders (SUDs), and recurrent affective or psychotic disorders (ie, severe mental illness [SMI]).

Methods: The VA Information and Computing Infrastructure (VINCI) Data Navigators provided aggregate phenotype counts and relevant ICD and clinic codes from about 350,000 Veterans in the US Department of Veterans Affairs national Million Veterans Program (MVP). Data were collected by MVP between 2011 and 2017, without relationship to the current work. Work on this report and related analyses took place from April 11, 2020, to October 6, 2021.

Results: We compared 3 suicide risk groups: 1,269 Veterans with previous ATTP, 109,836 with SI only, and 242,872 without previous suicidality. Nearly three-fourths of ATTP Veterans did not have SMI diagnoses. RR for ATTP behavior was highest in Veterans with EB (25.4), followed by those with SUD (13.9); both RRs were greater than RRs for Veterans with schizophrenia (7.4) or bipolar disorder (7.8). ATTP RR was greater for smoking than for major depressive disorder (5.0 vs 3.5, respectively). RR for smoking, across clinical groups, was strongly related to RR for ATTP risk, but not for SI only.

Discussion: ATTP suicidal behavior was more strongly associated with EB and SUD than with SMI. Suicide risk is associated with SUD or EB beyond SMI, so routine clinical encounters in primary care and emergency settings must recognize EB, SUD, and smoking as risks for severe suicidal behavior.