Nearly all mental disorders increase suicide risk; however, some better predict ideation versus attempts. The interpersonal theory of suicide provides a framework to understand these relationships, via the constructs of thwarted belongingness, perceived burdensomeness, and acquired capability. The current study examined the relationships between various mental disorders and theory constructs among 997 adult outpatients, controlling for sex and age. Disorders generally symptomatically associated with social withdrawal or potential liability to others (i.e., depressive and bipolar disorders, social phobia, borderline personality disorder, schizophrenia and other psychotic disorders, certain drug dependence) were uniquely positively associated with thwarted belongingness and perceived burdensomeness. Disorders associated with potential exposure to painful and provocative events (i.e., posttraumatic stress disorder, schizophrenia and other psychotic disorders, certain drug use) were associated with increased acquired capability. Notably, alcohol use disorders, attention-deficit/hyperactivity disorder subtypes, and panic/agoraphobia were negatively associated with thwarted belongingness or perceived burdensomeness; avoidant personality disorder, and certain anxiety disorders and drug use disorders, were associated with decreased acquired capability. Importantly, disorders associated with both thwarted belongingness and perceived burdensomeness may place individuals at greatest risk for suicide if acquired capability develops. Implications for comorbidity and suicide risk assessment and treatment are discussed.