Personality Functioning, Maladaptive Traits, and Emotion Dysregulation in Severe Psychiatric Inpatients: Associations with Psychological Symptom Domains

The Hierarchical Taxonomy of Psychopathology (HiTOP) has gained substantial empirical support as a dimensional model for understanding severe psychopathology. However, the integration of the Level of Personality Functioning (LPF) into this framework remains debated, and its specific contribution to understanding psychological symptoms is less extensively studied. This study examined the associations among impairments in personality functioning (self and interpersonal), maladaptive personality traits, alexithymia, and emotion regulation with psychological symptoms in a transdiagnostic sample of severe psychiatric inpatients. Ninety-three patients from a comprehensive mental health facility providing sub-acute care and long-term rehabilitation completed the SCL-27 for symptom assessment, LPFS-BF for personality functioning, PID-5-BF for maladaptive traits, the Toronto Alexithymia Scale and the Cognitive Emotion Regulation Questionnaire for emotion dysregulation. Standard and hierarchical multiple regression analyses were conducted to examine unique incremental associations across symptom domains. Self and interpersonal functioning measures showed strong associations with all symptom scales, while alexithymia was also broadly associated with symptom severity in initial models. After accounting for emotion dysregulation variables, interpersonal functioning remained uniquely associated with dysthymic, social phobia, and mistrust symptoms, while self-functioning associations were no longer evident for vegetative, depressive, and agoraphobic symptoms. These findings demonstrated that core personality functioning impairments accounted for psychiatric symptom expression beyond maladaptive traits alone. The results supported greater integration of personality functioning into dimensional models of psychopathology like HiTOP.