A new study shows that children of Holocaust survivors do not face a greater risk of developing schizophrenia. However, the findings reveal that children whose parents were in the womb during the Holocaust are more likely to develop a more severe form of schizophrenia.
This finding suggests an epigenetic mechanism, essentially arising from environmental influences on the way genes expressed themselves.
“Likely these are transmitted from the parental environment to the child,” said Professor Stephen Levine at the University of Haifa.
Levine led research with Professor Itzhak Levav of the Department of Community Mental Health at the University of Haifa, together with Inna Pugachova, Rinat Yoffe, and Yifat Becher of the Ministry of Health.
The findings are published in the journal Schizophrenia Research.
The researchers evaluated data on 51,233 individuals who immigrated to Israel through 1966. The study subjects were those who had experienced the Holocaust directly, while the comparison group comprised of individuals who immigrated to Israel before the Holocaust began in their respective country of origin.
All the second-generation subjects were born between 1948 and 1989 and were followed through 2014 to determine whether or not they suffered from schizophrenia.
The question of the impact of Holocaust exposure among second-generation survivors has been debated for some time among researchers. Clinic-based studies have found that trauma increases psychopathology in the children of Holocaust survivors, while community-based studies have found that there is no such link among adults, as noted by Levav and collaborators in two large representative samples in Israel
The researchers sought to examine whether parental Holocaust exposure is associated with schizophrenia among second-generation survivors. The good news is that the association was not significant.
However, a more specific inquiry revealed that the children of mothers with Holocaust exposures in the womb only were 1.7 times more likely to have a more severe course of the disorder. Similarly, offspring to mothers exposed to the Holocaust in the womb and thereafter were 1.5 times more likely to have a more severe course than mothers not exposed.
The children of fathers exposed in the womb and thereafter were 1.5 times more likely to develop severe schizophrenia, and those whose fathers were exposed at ages one to two had offspring with similar risk.
Overall, transgenerational genocide exposure was unrelated to the risk of schizophrenia in the survivor’s children, but was related to a course of deterioration in schizophrenia during selected parental critical periods of early life.
The findings inform health policy decision makers about refugees who suffered from extreme trauma, and extend existing results regarding the transgenerational transfer of the effects of famine and stress in parental early life.
Source: University of Haifa