Impact of diagnostic genetic testing for familial dementia: experiences of patients and relatives

While memory clinic patients express interest in diagnostic genetic testing for monogenic causes of dementia, its personal consequences remain unclear. We explored the psychosocial and behavioral impact on patients and relatives. In this mixed-methods study, we examined 31 patients meeting eligibility criteria for genetic testing as part of their diagnostic work-up at Alzheimer Center Amsterdam. Patients were 45% female, and aged 61 ± 8 (MMSE = 23 ± 5, 25 dementia [15 AD, 4 PPA, 6 other], 1 MCI, 1 SCD, 4 other/undetermined). Twenty-five tested negative, and six positive. Per case, either the patient, one or more relatives, or both were included (3/31 patient only; 5/31 relative(s) only; 23/31 both), yielding 26 patients and 29 relatives (55% female, and aged 54 ± 12). Participants completed questionnaires assessing psychosocial and behavioral factors at first visit, one week post-counseling, and one week and three months post-disclosure. We used linear mixed models to calculate effects of group, time, and interaction, with patients and relatives analyzed separately. In addition, 8 patients and 10 relatives participated in 13 semi-structured interviews, analyzed inductively. Average anxiety, depression and distress levels remained below clinical threshold in patients and relatives. Anxiety was lower in patients one week and three months post-disclosure, and lower in relatives one week post-disclosure. At baseline, positive patients reported lower social support, and over time they discussed genetic testing less often with others. Positive patients more often reported having registered for research participation. Patients’ decision regret was low and independent of group. Interviews revealed that participants receiving negative results felt relieved their offspring were not at genetic risk, but some remained uncertain about the cause of their disease. Those receiving positive results experienced emotional distress about potential implications for their children, yet appreciated having clarity. Participants related to positive cases described challenges in receiving emotional support. While diagnostic genetic testing was well tolerated and valued, it also revealed complex emotional, relational, and practical consequences for patients and families, indicating a need for psychosocial support. As this was an exploratory study, findings should be interpreted cautiously and validated in future research.