M-5 Cluster B Disorders

Cluster B disorders in the DSM-5 include Narcissistic, Antisocial, Borderline, and Histronic personality disorders. In order to be diagnosed with one of these, the individual must exhibit at least two of four typical defining characteristics in thoughts, feelings, interpersonal relationships, and impulse control. Their patterns of behavior are pervasive, inflexible, deviate markedly from cultural norms and expectations, are stable over time, and lead to distress or impairment. Those with one of these diagnoses struggle with distorted thinking patterns, problematic emotional responses, over- or under-regulated impulse control, and interpersonal difficulties. They find it difficult to regulate their emotions, tend to exhibit overly emotional or unpredictable thinking or interactions with others. Their behaviors are often considered threatening or disturbing. These personality disorders may share some atypical brain features, some of which affect the amygdalae, two tiny brain organs that are involved in regulating emotion and alerting to potential danger. More tomorrow.