Huntington's disease is characterized by motor, cognitive, and neuropsychiatric symptoms. This study reviews original research on psychopathology in Huntington's disease that uses standardized instruments in verified gene carriers. Frequently reported neuropsychiatric symptoms are depressed mood, anxiety, irritability, and apathy, with prevalences of 33% to 76%. Obsessive-compulsive symptoms and psychosis occur less often with prevalences of 10% to 52% and 3% to 11%, respectively. Available research provides little insight into the true prevalences of psychopathology in Huntington's disease due to small sample sizes, use of different methodologies, and lack of comparison groups. Future research requires larger cohorts stratified to disease stage, consistent methodologies, and adequate comparison groups.