Self-selection in predictive testing for Huntington's disease.

Several studies have reported favorable psychological reactions to predictive testing for Huntington's disease (HD). However, few at-risk persons have been tested, and there is evidence that some at-risk people avoid testing because they fear being unable to cope with the information. Favorable psychological reactions may result from self-selection of persons who believe they are better-equipped to handle "bad news." We surveyed 32 at-risk persons who had considered, but not chosen, testing and 66 persons who had been previously tested. Twelve persons decided not to be tested (No group); 20 persons postponed testing until some later date (Maybe group). Of the two untested groups, a significantly greater number of the No group had not been tested because they anticipated problems associated with their emotional reactions. The persons in the Tested group had less often anticipated problems with their emotional reactions; and among the minority who had anticipated some problems, most did not question their ability to cope. We conclude that the Tested persons are psychologically selected for favorable responses to genetic testing. Surveys of health professionals suggest that a sizable minority would disclose genetic disease risk whether or not people want it. Thus, people who would not choose to be tested might be persuaded to do so, or have results thrust upon them. We should be wary about assuming that the generally favorable reactions to HD testing will continue when testing becomes more widespread, as is likely to happen with simplification of the technology and acceptance of these tests by the medical community.