Participants ages 18 and older who have had a positive genetic test result more than 6 months earlier regarding HD or who have a family history of HD but no predictive testing and who do not have symptoms of HD may be eligible for this study. Recruitment is done through HD clinics, support groups, and online websites and mailing listservs. About 260 people will be in the study. Participants will complete a survey taking 30 to 40 minutes to do. Two survey versions are available: for those who are gene carriers and for those at risk. Participants are asked to complete the version applying to them. The survey can be done online or through a hard copy to complete at home and send to NIH. This survey is anonymous.