THE IMPACT OF PERSONALITY DYSFUNCTION AND MALADAPTIVE TRAITS IN ADULT ADHD

Abstract

This doctoral project examines how dimensional models of personality pathology—particularly the DSM-5 Alternative Model for Personality Disorders (AMPD)—can enhance understanding and treatment of adult Attention-Deficit/Hyperactivity Disorder (ADHD). Moving beyond traditional categorical approaches, the AMPD integrates general personality dysfunction with maladaptive traits, providing a framework for capturing the heterogeneity of adult ADHD, its variable functional impairment, and differences in treatment response. Across studies, adult ADHD was consistently associated with elevated Disinhibition and Negative Affectivity, situating the condition within contemporary dimensional models of personality and psychopathology. At the same time, variation in general personality functioning and maladaptive trait configuration contributed to clinically meaningful differences beyond symptom severity, including functional impairment and differentiation from other psychiatric conditions. These dimensions were also associated with treatment processes and outcomes. Interpersonal traits reflecting mistrust and avoidance were linked to premature discontinuation of pharmacological treatment, while elevated personality dysfunction and maladaptive traits were associated with more limited functional improvement, despite reductions in core ADHD symptoms. Taken together, the findings suggest that dimensional models of personality pathology provide clinically relevant information beyond categorical diagnosis. Incorporating the AMPD framework, particularly the assessment of personality functioning, may support more precise formulation, improve prediction of treatment adherence and outcome, and inform individualized interventions. These results align conceptually with the ICD-11 personality disorder model and highlight the potential value of integrating pharmacological and personality-informed psychological approaches to improve real-world functioning in adults with ADHD.