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In the first RCT to examine genetic susceptibility testing for AD, uptake rates were sufficiently high to merit concern that future test demand may strain available education and counseling resources. Findings suggest that susceptibility testing for AD may be of particular interest to women, college educated persons, and persons below age 60.

Advances in genetic research have provided a basis for susceptibility testing for Alzheimer disease (AD). Prior surveys have examined attitudes toward genetic testing for AD in hypothetical scenarios, but it is unclear what reasons would motivate people to seek testing in real-life situations. This study presents data from the first randomized trial to evaluate genetic susceptibility testing for asymptomatic adult children of people with AD. We examined (1) reasons endorsed as motivations for seeking testing, (2) demographic characteristics associated with these reasons, and (3) how these reasons related to the eventual decision to pursue testing. Eligible participants were 206 adult children of people with AD (mean age 53 years; 72% female; 93% white), 77.7% of whom (n = 160) went on to seek testing. Participants endorsed numerous reasons for seeking susceptibility testing (mean 7.2), encompassing a range of motivations. The most commonly endorsed reasons were as follows: (1) to contribute to research (93.9%), (2) to arrange personal affairs (87.4%), and (3) the hope that effective treatment will be developed (86.8%). Women strongly endorsed more reasons for seeking testing than men (p < 0.05). The best predictor of actual pursuit of testing was strong endorsement of the need to prepare family members for AD (odds ratio = 3.3, p < 0.01). Findings suggest that genetic susceptibility testing is of interest to individuals at risk for AD for a variety of reasons, even in the relative absence of available treatments.

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lifetime risk estimates of AD based on the same risk factors excluding APOE genotype. Perceptions of personal risk (PPR) for AD were assessed six weeks after risk assessments. PPR were correlated with actual lifetime risk estimates (r = 0.501; p < 0.0001). After controlling for lifetime risks communicated to participants, age, and number of affected relatives, PPR scores among those with an epsilon4-positive test result (the test result associated with increased AD susceptibility) (adjusted mean: 3.4 (SD: 0.7)) were not different from the PPR scores in the CONTROL GROUP (adjusted mean: 3.4 (SD: 0.7) (F1,91= 1.98; p = 0.162). Again, controlling for lifetime risk estimates, age, and number of affected relatives, the PPR score of those receiving an epsilon4-negative test result was significantly lower (adjusted mean: 3.1 (SD: 0.8)) than those in the CONTROL GROUP (adjusted mean: 3.4 (SD: 0.7) (F1,95 = 6.23; p = 0.014). Perceptions of risk of developing AD are influenced by genetic test disclosure in those receiving epsilon4-negative, but not those receiving epsilon4-positive test results. Despite the reduced perceptions of risk in the former group, there was no evidence of false reassurance (i.e., perceiving risks as equal to or lower than population risks of AD), although this possibility should be assessed in other testing contexts.