Cambodian psychiatrist Chhim Sotheara told the judges at a UN-back tribunal Tuesday that the trial of senior members of the regime will help treat mental wounds of the survivors of the regime.

The doctor was called as a witness in the trial of Duch, who is charged atrocity crimes allegedly committed when he ran two infamous Khmer Rouge prisons and an execution site on the outskirts of Phnom Penh.

“The victims from S-21 are still suffering, remembering the past killings and torture, having nightmares and depression, and difficulties of this lack of recovery affects their current living,” Chhim Sotheara said, referring to Tuol Sleng prison by its Khmer Rouge nomenclature.

Two out of five Cambodians suffer psychiatric problems as a result of the Khmer Rouge, Chhim Sotheara said.

“Our victims have suffered from various psychiatric problems, such as [post traumatic stress disorder], depression, pressure, bodily suffering and other troubles, including high blood pressure, chronic disease and diabetes, concerning the killing and torture by the Khmer Rouge,” he said.

“The trials can reduce the depression of the victims,” he said. “The recovery of psychiatric conditions of the victims of the Khmer Rouge depends on the loyalty of the accused, the former senior Khmer Rouge leaders to come out. The knowledge of facts, the acceptance of real justice and apologies are important factors helping treat the conditions of the victims.”

Duch, 66, whose real name is Kaing Kek Iev, faces charges of war crimes, crimes against humanity, torture and murder. Prosecutors say 12,380 people died in his prisons.

Duch told tribunal judges Tuesday he was “completely responsible” for psychological problems brought on by practices of the Khmer Rouge.