PREDICTIVE TESTING FOR HUNTINGTON DISEASE - NONPARTICIPANTS COMPARED WITH PARTICIPANTS IN THE DUTCH PROGRAM

Attitudes toward predictive testing programs, in individuals who choos e not to undertake the test (i.e., nonparticipants), may be influenced by fears of an unfavorable result. The reasons not to participate in predictive testing programs for Huntington disease (HD) were studied i n members of the Dutch Huntington Association who were at 50% risk. Th ey had completed the same baseline psychological questionnaires as had the participants in the Dutch DNA-testing program. The group of 34 no nparticipants was similar to the tested participants in the Dutch pred ictive testing program, with respect to average age (31.1 years), male :female ratio (1:2), the frequency of a stable relationship (70%), and a level of education (67% had high school education or higher). Testi ng did not seem to be a realistic option for nonparticipants for impro ving their quality of life. In comparison with participants, nonpartic ipants had a significantly more pessimistic outlook on themselves and their futures. When asked to consider the possibility of an unfavorabl e result, nonparticipants expected more difficulties in their families ; more problems for their children, their partners, and themselves; a lowered quality of life; and, more often, a depressive reaction. In th eir opinion, a favorable result would reduce the problems for their ch ildren but not for themselves, a result that was found more often in t he nonparticipant than in the participant group. Nonparticipants learn ed about their being at risk for HD during adolescence (mean age 15.6 years), whereas participants did so in adulthood (mean age 22.7 years) . The nonparticipants' attitude toward the test might be explained by the influence of HD in the adolescent's separation-individuation proce ss and personality development. This finding could be relevant for fut ure research and for the discussion about testing minors for delayed-o nset disorders.