It’s often argued that telling people that they carry genes increasing their risk of Alzheimer’s will simply upset them to no purpose. A new study challenges that idea.
The study, involving 648 middle-aged adults tested for the “Alzheimer's gene” APOe4, found that 4% were in the highest risk group (carrying two copies of APOe4), while 34% had a single copy, and 62% had none. A year later, APOe4 carriers did not experience more anxiety, depression or distress than non-carriers, and were more active in efforts to reduce their risk of Alzheimer's disease — by exercising, eating a healthy diet and taking recommended vitamins and medications.
However, a more recent study of older adults has found that being told of their genetic status affected their cognitive performance. Specifically, those told they had the Alzheimer's gene judged their memory more harshly, and performed more poorly on a verbal memory test, than those who had the gene but had chosen not to be told. Similarly, those told they did not have the Alzheimer's gene judged their memory more positively, and performed better on the memory test, than those who didn't have the gene but didn't know that.
This is, of course, entirely in keeping with research showing that a person's beliefs about their memory have a significant effect on their cognition.
The study involved 144 cognitively normal older adults (aged 52–89), of whom 74 knew their genetic status (25 had the gene vs 49 without), and 70 did not (25 with vs 45 without).
Taking the findings from both these studies together, it seems likely that providing appropriate advice and support to those informed of their negative genetic status is vital, and that this may be particularly crucial for older adults, who may be more vulnerable to negative results.
Lineweaver TT; Bondi MW; Galasko D; Salmon DP: Effect of knowledge of APOE genotype on subjective and objective memory performance in healthy older adults. Am J Psychiatry 2014; 171:201–208