BackgroundAncestral trauma may result in increased sensitivity to adverse events among offspring. This increased sensitivity may be expressed in heightened PTSD symptoms, and by experiencing intrusive linkage between ancestral trauma and current traumatic events experienced by offspring. Sleep problems are another major consequence of traumatic events, but they have been underexplored in the context of intergenerational effects of trauma. Therefore, the current study examines the role of intrusive linkage and PTSD symptoms as potential mechanisms that may increase sleep problems following the October 7, 2023, attack and subsequent war among Holocaust descendants.MethodsThe study included 359 Israeli participants (T1 age=45.44 ± 12.85), who completed four waves of sampling before (T1-T2) and after (T3-T4) the October 7 attack. Sleep problems (T2-T4), PTSD symptoms (T3-T4), and intrusive linkage between the Holocaust and the Israel-Hamas War (T3-T4) were measured using standardized questionnaires.ResultsPTSD symptoms, intrusive linkage, and sleep problems decreased from T3 to T4. A reciprocal nature of effects among PTSD symptoms, intrusive linkage, and sleep problems emerged. Indirect effects were found between Holocaust background (having Holocaust survivor grand/parents) and T4 intrusive linkage via T3 PTSD symptoms. Indirect effects were also found between Holocaust background and T4 sleep problems via T3 PTSD symptoms and via T3 intrusive linkage.ConclusionThe findings suggest that intrusive linkage and PTSD symptoms can serve as mechanisms for amplifying sleep problems among offspring of traumatized grand/parents. Therefore, sleep disturbances might be a key outcome of increased susceptibility to negative events, which can be linked to intergenerational trauma effects.