Predictors of suicidal ideation in social anxiety disorder - evidence for the validity of the Interpersonal Theory of Suicide.

Abstract Background: This study aims to identify covariates of suicidal ideation (SI) in a large sample of individuals diagnosed with social anxiety disorder (SAD). Methods: In a cross-sectional design, 305 individuals (38.4±14.1 years, 59% female) with SAD were assessed by the Social Phobia Inventory, Beck Depression Inventory, Adverse Childhood Experience Questionnaire, State Trait Anger Expression Inventory, Beck Scale for Suicidal Ideation and the Interpersonal Needs Questionnaire. Results: SAD individuals with SI (n = 142, 46.6%) reported higher SAD and depression symptoms, more adverse childhood experiences (ACE), higher state anger (SA), perceived burdensomeness (PB) and higher thwarted belongingness (TB) compared to SAD individuals without SI (n = 163, 53.4%). In binary logistic regression, PB (odds ratio (OR)=1.11, 95% confidence interval (CI)=1.06-1.15), TB (OR=1.05, 95% CI=1.02-1.07), SA (OR=1.07, 95% CI=1.01-1.13) and ACE (OR=1.18, 95% CI=1.03-1.35) emerged as significant covariates of acute SI (Nagelkerke's R2 = .39). Receiver operating characteristic (ROC) curves showcased the following areas under the curve (AUC): PB (AUC=.78), TB (AUC=.76), SA (AUC=.62) and ACE (AUC=.62). Multinomial logistic regression (no SI = ref.) showcased similar results for passive and active SI (n = 42), with SA reaching significance only for active SI. The Youden index identified appropriate cut-off values for PB, TB, SA and ACEQ by maximizing sensitivity and specificity. Limitations: Cross-sectional design and self-reporting measures limit generalization. Conclusion: Our findings confirm the validity of the Interpersonal Theory of Suicide concerning SI in SAD. PB and TB with SA and ACE may support the valid assessment of SI in therapeutic settings.