This document provides an overview of personality disorders, including their definition, characteristics, classification, causes, diagnosis, treatment, and prevalence. Personality disorders are defined as rigid and maladaptive patterns of behavior that cause problems in relationships and work. They are classified into three clusters (A, B, and C) based on their characteristics. While the causes are unknown, genetic and environmental factors like childhood abuse are thought to play a role. Personality disorders are diagnosed based on a psychological evaluation and history. Treatment may include psychotherapy, behavior therapy, and medication to treat related symptoms. The outlook varies depending on the specific disorder, with some improving over time and others requiring ongoing treatment. Prevalence estimates range from around 1-10% depending on