A majority of Israel’s Holocaust survivors suffer from depression, sleeping disorders or other emotional distress, according to a survey released Tuesday by a leading advocacy group.

The Foundation for the Benefit of Holocaust Victims in Israel issued its report on the eve of International Holocaust Memorial Day, which this year marks the 65th anniversary of the liberation of the Auschwitz death camp in the waning days of World War II.

The survey found that two-thirds of Israel’s 220,000 survivors experience some form of distress. The study, conducted by the Center for Research on Aging of the Israeli Myers-JDC-Brookdale Institute, was based on comprehensive government data on all the survivors.

A smaller sample of 400 survivors who receive home care showed that half suffered from depression and 80 percent complained of sleep disorders.

About 6 million Jews were killed by Nazi Germany during World War II.

Allied armies freed thousands of emaciated Jewish inmates from Nazi camps in the closing months of the war. The latest study concluded that many camp survivors, as well as a large number of Jews who survived the war but did not go through the Nazi camps, have been permanently scarred by their experiences during the Holocaust.

Zeev Factor, chairman of the group that issued the report, said the needs of Holocaust survivors increase as they grow older.

“The biggest need is how to overcome their loneliness,” said Factor, an Auschwitz survivor. “They are very old people. Many of them are absolutely alone, and they have no family.”

Factor said that retirement has added to their torment.

“They have all the time to think and live in the past again,” he said.