Examining the Joint Factor Structure of Mania, Internalizing, and Thought Disorder Symptoms in a Large Online Sample

The optimal classification of mania symptoms within dimensional models of psychopathology remains unclear, due in part to most prior research using composite categorical ratings of mania/bipolar disorder rather than ratings of specific symptoms. We addressed this gap by examining the structure of self-reported symptom-level ratings of mania, internalizing, and thought disorder in adults (N = 1,112) recruited online who self-identified as having significant mental health histories. Although prior research suggests that mania symptoms overlap strongly with both internalizing and thought disorder, our results indicated much closer alignment with thought disorder than internalizing when examining a two-factor structure. Even when examining a three-factor structure, manic symptoms such as grandiosity loaded strongly onto a common factor with positive psychosis symptoms. However, symptoms such as racing thoughts and excessive energy loaded strongly onto a separate Agitation factor potentially representing a subspectrum within thought disorder. Agitation showed some unique correlates (e.g., with stimulant medication use), indicating heterogeneity within the broader thought disorder spectrum. Future directions extending this research include incorporating assessment of other psychopathology (e.g., externalizing), examining the cross-method consistency of results (e.g., when using interviews), and determining symptom course and interrelations using intensive longitudinal designs.