The findings add to an ongoing debate about the psychological effects of trauma.

Holocaust survivors more likely to develop dementia – new study

Polish-born Holocaust survivor Meyer Hack shows his prisoner number tattooed on his arm during a news conference at the Yad Vashem Holocaust Museum in Jerusalem June 15, 2009.. (photo credit: REUTERS)

The findings, recently published in The Journal of Traumatic Stress by Dr. Arad Kodesh, Prof. Itzhak Levav and Prof. Stephen Levine, add to an ongoing debate about the psychological effects of extreme adversity.

Some scientists hypothesize that those who experience horrific events may develop mechanisms that make them resistant to neurodegenerative diseases such as dementia, which is characterized by a decline in cognitive ability and a decrease in daily activity. Others argue, however, that the risk of developing these diseases may increase with exposure to trauma, Levine explained.

The University of Haifa researchers found that 16.5%  of those who were exposed to the Holocaust – more than 10,000 participants, or about one-fifth of the total study pool – contracted dementia, compared with a rate of 9.3% among the other participants.

The results of the study are therefore consistent with the hypothesis that exposure to the trauma of genocide increases vulnerability to the risk of dementia later in life.

The researchers analyzed registry data on 51,752 Israeli residents who were born between 1901 and 1945 and who did not have a history of dementia during the period 2002 and 2012, but who were still alive in 2012. They then reexamined whether those people developed the disease between January 2013 and October 2017.

The researchers classified participants by their exposure to the Holocaust based on government recognition and assigned hazard ratios from Cox proportional hazards-regression models to quantify risk of dementia, with adjustments made for demographic factors such as sex and age.

“The study findings are clinically significant in terms of the long-term identification of dementia among Holocaust survivors, and they may also be relevant regarding crimes against humanity in general,” Levine said. “The findings highlight the need for careful monitoring of cognitive decline in risk populations that experienced extreme and protracted trauma in general, and Holocaust survivors in particular.”