The vast majority of Holocaust survivors suffer from uncontrollable painful memories, according to a new study released on Wednesday. The study by Dr. Sonia Letzter-Pau at the University of Haifa's School of Social Work also found that more than two-thirds of the survivors with invasive memories actively attempted to avoid thinking about their experiences or entering situations that could remind them of the Holocaust. Letzter-Pau interviewed 178 elderly survivors who were children or babies during the Nazi era (born between 1928 and 1945), along with the eldest child of each. Survivors who lost one or both parents in the Holocaust or who were incarcerated in concentration or labor camps or ghettos, suffered more from invasive memories than those who had not lost parents or who ran away from home. The former group reported poorer physical and mental health and interpersonal functioning than the latter group. Those who were orphaned in the Holocaust, lived in ghettos or were sent to camps were more likely to suffer from mental stress and uncontrollable memories. Letzter-Pau confirmed her hypothesis that the children born to survivors after the Holocaust would also be affected by what their parents had endured. Holocaust trauma was more intense in children of survivors who went through more difficult experiences, she found. "It is important to understand the centrality of invasive Holocaust memories and the avoidance of them when individuals are treated," she said. "In addition, when the children of survivors are treated, therapists must investigate the mother's experiences, and the connection between the mother and her son or daughter must be one of the focuses of therapy."