AbstractIntroductionAnxiety and suicidal ideation have been shown to be positively related in adolescents. However, less is known about the strength of this association across different types of anxiety or the mechanisms through which this relation exists. Joiner's interpersonal theory of suicide suggests that thwarted belongingness (TB) and perceived burdensomeness (PB) lead to suicidal ideation; these constructs may explain a pathway through which anxiety and suicidal ideation are related. It was hypothesized that TB would mediate the relation between social anxiety disorder (SAD) symptoms and suicidal ideation, and PB would mediate the relation between generalized anxiety disorder (GAD) symptoms and suicidal ideation.MethodsThese longitudinal mediation models were assessed using data collected from 147 depressed adolescents, who were recently hospitalized for suicidal ideation or behavior, enrolled in a randomized controlled trial (RCT).ResultsConsistent with study hypotheses, PB mediated the relation between GAD symptoms and suicidal ideation severity. However, TB did not mediate the relation between SAD symptoms and suicidal ideation severity.ConclusionThese results suggest that screening for and addressing PB among youth with GAD may help reduce risk for suicidal behavior.