Huntington disease as a dual diagnosis disorder: data from the National Research Roster for Huntington disease patients and families.

Although an extensive literature characterizes a linkage between primary mental illnesses and substance use disorders, a paucity of research exists concerning dual diagnosis phenomena in Huntington disease (HD). Data from the National Research Roster on HD suggest that higher levels of alcohol and cigarette use are associated with greater ratings of psychiatric symptoms and a younger age of HD symptom onset, and that progressive alcohol use after HD symptom onset is linked with worsening psychiatric symptom progression. These findings suggest HD entails dual diagnosis phenomena similar to that identified in patients with primary psychiatric disorders.