Children of Holocaust survivors whose mothers were older than five when Nazi persecution began faced more than double the risk of being hospitalised for schizophrenia and related disorders, according to a new study published in the American Journal of Psychiatry.
The research, led by Prof Hagit Hochner and Dr Iaroslav Youssim from the Hebrew University of Jerusalem and Prof Dolores Malaspina from Mount Sinai School of Medicine in New York, examined whether severe trauma experienced before conception could be linked to psychiatric illness in the next generation.
Using linked Israeli health records, the researchers found the strongest association among children whose mothers were older than five at the start of Nazi persecution in their countries of origin.
The study does not prove that Holocaust trauma caused schizophrenia in survivors’ children. But it provides significant population-based evidence that the timing of a parent’s childhood trauma may be linked to serious mental illness risk in the next generation.
“Our work underscores that war does not only have devastating immediate consequences, but also places a profound intergenerational burden on the future,” Hochner said.
The researchers used the Jerusalem Perinatal Study, which recorded births in West Jerusalem from 1964 to 1976. These records were linked to Israel’s National Psychiatric Registry through December 2004 to identify hospitalisations for schizophrenia and related disorders.
The analysis included two large samples: 14,759 children of 7,316 mothers and 18,085 children of 8,833 fathers. Of these, 3,913 children had exposed mothers and 5,672 had exposed fathers.
Parents were classified as exposed if they were Jewish, born in European countries under Nazi rule, and immigrated to Israel after anti-Jewish persecution had begun in their country of origin. Unexposed parents were of European descent but had not lived under Nazi rule.
The researchers then divided exposed parents according to age when persecution began: five years old or younger, and older than five.
That age split became central to the findings.
Children of mothers who were older than five when persecution began had a substantially higher risk of schizophrenia. The association remained after adjustment for social and demographic factors, birth weight and the mother’s own history of psychiatric hospitalisation.
According to the study, maternal exposure after age five was linked to a hazard ratio of 2.71 before adjustment and 2.38 after further controls. Paternal exposure after age five was initially linked to a smaller increase, with a hazard ratio of 1.52, but the association weakened after adjustment for social and demographic factors.
No increased risk was found among children whose parents were five or younger when persecution began.
The researchers suggested very young children may have been more protected by caregivers, or may have understood danger differently because of their stage of development. They also noted that a child’s ability to perceive threat changes with
cognitive, social and psychological growth.
The stronger maternal association raised questions about how trauma risk may be passed between generations.
The authors said possible pathways include effects on the mother’s later pregnancy environment, early parenting, or biological changes linked to stress. They also raised the possibility of epigenetic mechanisms, where stress may affect how genes are expressed without changing the genetic code itself.
However, the researchers were careful about the study’s limits. The data could not measure each survivor’s personal Holocaust experience, the intensity of trauma, the family environment in which the children were raised, or cases that emerged after the registry follow-up ended.
The exposure definition was also ecological, meaning it was based on country of birth, Nazi rule and timing of immigration rather than direct testimony from each survivor. That approach allowed a large-scale study but may not reflect the full variation of personal experience.
Even so, the study is notable because it uses official birth and psychiatric registry data across two generations, rather than relying only on self-reported family history.
It also adds to wider research on intergenerational trauma, while avoiding the stronger claim that trauma is simply inherited in a direct biological sense.
Hochner said the findings had wider relevance as conflict continues to displace and traumatise populations around the world.
“Understanding these preconception pathways is crucial for anticipating future public health burdens,” she said. “Ending war and striving for peace is a public health imperative.”
The study, Schizophrenia in Offspring of Holocaust Survivors: Intergenerational Effects of Preconception Parental Trauma Within the Jerusalem Perinatal Study, was published in the American Journal of Psychiatry in June 2026.