Purpose The pattern of executive dysfunction reported in juvenile myoclonic epilepsy (JME) resembles that of patients with cluster B personality disorders. This study examined whether executive dysfunction and maladaptive behavior reported in patients with JME are related. Method Sixty patients with drug-refractory JME were administered tests of intellect, memory, and executive dysfunction. Anxiety, depression, personality traits, impact of epilepsy, and perceived cognitive effects of antiepileptic drugs were measured. Results Half of the cohort exhibited moderate to severe anxiety symptoms. The patients performed most poorly on naming ability and inhibition switching. Duration of epilepsy exacerbated poor performance on inhibition switching. Females presented with pathological scores for neurotic and introvert traits and males for introvert traits. Abnormal personality traits and psychiatric disorders were associated with worse intellectual and executive functioning. People with extreme Eysenck Personality Scale — Brief Version (EPQ-BV) scores demonstrated the greatest level of executive impairment. Furthermore, the same degree of dysfunction was not seen in any individual with unremarkable EPQ-BV scores. Conclusion This study indicates that specific patterns of executive dysfunction are related to maladaptive behavior in JME. Distinct behavioral patterns may be used to identify functional and anatomical differences between people with JME and for stratification to enable gene discovery.