The chances of Holocaust survivors developing dementia are 1.21 times higher than of those who did not experience the Holocaust, according to a new study conducted at Haifa University.
In this study, published June 17 in the Journal of Traumatic Stress (Exposure to Genocide and the Risk of Dementia), Dr. Arad Kodesh, Prof. Yitzhak Levav and Prof. Stephen Z. Levin of Haifa University examined the risk of developing dementia, which is characterized by a decline in cognitive ability and a decrease in daily activities among Holocaust survivors – A subject that has not been examined previously.
“There are different and contradictory approaches to the issue of the psychological effects of Holocaust terror on the survivors,” said Professor Levin. “On the one hand, those who survived the Holocaust may have developed mechanisms that enable them to be immune to neurodegenerative diseases such as dementia. On the other hand, the trauma of the Holocaust may actually increase the risk of developing such diseases. In our study, we found that survivors are more vulnerable to developing dementia.”
Competing hypotheses stating that past genocide exposure reduces (owing to resilience) versus increases (owing to vulnerabilities) the risk of dementia are yet to receive empirical support. This study tested these competing hypotheses.
Registry data were extracted on 51,752 Israeli residents without dementia from September 2002 to January 2012; individuals were born between 1901 and 1945, alive on January 2012, and followed-up for the risk of dementia between January 2013 and October 2017.
Groups were classified as exposed to the European Holocaust, based on government recognition, or unexposed. Hazard ratios (HRs) from Cox regression models were used to quantify the risk of dementia between the groups, adjusting for demographic and diagnostic covariates; additionally, 12 sensitivity analyses were computed.
In total 10,780 participants (20.8%) were exposed to the Holocaust and 5,584 (10.8%) were diagnosed with dementia during follow-up. Dementia rates were 16.5% in the Holocaust-exposed group and 9.3% in the unexposed group.
Of the 40,792 subjects who did not survive the Holocaust, 3803 subjects, who constitute 9.3% of this population, also developed dementia.
After taking into account various factors such as sex, age, and death during the period of follow-up, Holocaust survivors were 1.21 times more likely to develop dementia than people who did not experience the Holocaust.
“The results of the study have a clinical significance in the long-term identification of dementia in Holocaust survivors and can also be relevant to the perpetrators of crimes against humanity in general,” concluded Prof. Levin. “This sharpens the need for close monitoring of cognitive withdrawal in a risk population that experienced extreme and continuous trauma in general and Holocaust survivors in particular.”
“In addition to the findings, it is important to study prolonged stress situations as a risk factor for dementia,” he noted.