Psychological effects of presymptomatic DNA testing for Huntington's disease in the Dutch program

This study assessed the 6-month follow-up effects of presymptomatic DNA testing for Huntington's disease (HD) in 73 individuals at 50% prior risk who were identified either as carriers of the HD gene (N = 29) or as noncarriers (N = 44). The subject's knowledge of being a gene carrier was expected to induce intrusive emotions, denial-avoidance behavior, and pessimistic expectancies of the future and adjustment problems. The Impact of Event Scale, the Beck Hopelessness Scale, and the General Health Questionnaire were used as standard measures of psychological distress. At the disclosure of the test results, carriers had a strong increase in pessimistic expectations but showed a decline to baseline levels 6 months later. Noncarriers reported a steep decline in hopelessness compared with their pretest conditions but had increased scores after 6 months. Six months after the disclosure of the test results, both gene carriers and noncarriers reported a significant decrease in unwanted intrusive thoughts about HD. Carriers showed a slight increase in denial-avoidance behavior, whereas noncarriers showed a clear decrease. Our observations might indicate that tested individuals found relief from the prior psychological distress and that they were able to acknowledge the impact of the test result on their future. An unresolved question is how the foreknowledge will affect carriers as they approach the impending onset of the disease. Longer observation periods (> 6 months after disclosure) are required to study changes of the impact of DNA test results over time.