General and Specific Dimensions of Psychopathology and Subsequent Suicidal Behavior in a Nationwide Cohort of Adults With Psychiatric Conditions

BACKGROUND: The general psychopathology factor (P) and specific dimensions summarize psychiatric comorbidity, but their relative associations with subsequent suicidal behavior (SB) remain uncertain.METHODS: We analyzed a nationwide cohort with baseline assessment in 2000-2003 and follow-up in 2004-2013.Of 2,162,995 eligible individuals, 83,163 with at least one of 18 psychiatric conditions formed the analytic cohort.A two-parameter probit bifactor item response model estimated expected a posteriori (EAP) scores for P and four specific dimensions: Thought/Psychotic, Internalizing, Externalizing, and Neurodevelopmental.SB was defined as a recorded intentional self-harm or undetermined-intent injury (ICD-9-CM E950-E959, E980-E989).Cause-specific Cox models adjusted for age, sex, family income, urbanization, and Charlson Comorbidity Index.RESULTS: During follow-up, 1,116 individuals had recorded SB.Each additional psychiatric condition was associated with SB (hazard ratio [HR], 1.397; 95% confidence interval [CI], 1.303-1.498),and P improved model fit beyond diagnosis count (p<.001).In the joint model, P (HR, 1.386; 95% CI, 1.299-1.479)and Externalizing (HR, 1.176; 95% CI, 1.101-1.256)were positively associated with SB; Neurodevelopmental was inversely associated, and Thought/Psychotic and Internalizing were not.Externalizing remained associated after adjustment for baseline psychiatric hospitalization and psychotropic exposure, whereas the P association attenuated.Five-year cross-validated discrimination was modest for the five-dimensional and 18-indicator models (area under the curve, 0.673 vs 0.679).