Even a one-off, five-day therapy course can help Khmer Rouge survivors cope with PTSD and depression, a new report shows, though the long-term benefits of such therapy remain unclear.

Jennifer J Esala, a researcher at the Center for Victims of Torture in Minnesota, and Taing Sopheap, a researcher at the Transcultural Psychosocial Organization Cambodia (TPO), assessed the effectiveness of testimony therapy that had seen about 460 patients since its start.

During testimony therapy – brought to Cambodia by Danish expert Inger Agger in 2009 and adapted to Cambodian culture – Khmer Rouge survivors receive four days of individual counselling by TPO staff and one day of religious ceremonies.

The study consisted of a sample of 120 persons, who were split between a group of victims who received treatment and a control group. Researchers found that the therapy reduced symptoms of PTSD, depression and anxiety among the participants significantly within three months, but found no significant further reductions between three and six months after the therapy took place.

While the study gives hope to survivors, it also shows that benefits are mostly short term due to missing follow-up mechanisms. To remedy this, a hotline was introduced that those who had received testimony therapy can call if they find themselves in a psychologically stressful situation. The organisation now also travels to recipients’ villages for the five-day process “so that family members can participate and get to know the suffering of the survivor”.

Researchers estimate about 1.7 million Cambodians died under the Khmer Rouge regime, and Sok Phaneth, head of the TPO’s treatment centre in Phnom Penh, estimates that today around two in five Khmer Rouge survivors suffer from mental health problems such as PTSD and depression.

The head of the Ministry of Health’s department on mental health could not be reached yesterday, and Ly Sovann, spokesman for the ministry, could not provide information on mental health in Cambodia.

Samchan Sovandara, deputy head of the psychology department at the Royal University of Phnom Penh, highlighted the importance of Buddhist rituals in the therapy. “When people died in the Khmer Rouge, families do not know how they died . . . which causes mental health problems.”

With the help of Buddhist rituals prohibited under the Khmer Rouge – victims are able to find relief today, he said.

Sovandara called on the government to provide more funding to treat mental illness – a demand that was echoed by Documentation Center of Cambodia (DC-Cam) director Youk Chhang. While Cambodians were “resilient”, much more needs to be done, Chhang said.

Chhang criticised the lack of nationwide research. “The process remains a puzzle; which method really can respond to such a severely traumatised and terrorised population?”

The scars were not always visible, he said, offering an example from his own experience.

“I was imprisoned, tortured, and I don’t [always] feel it . . . But when I look at children of my age at the time, I feel emotional,” he said.

“[The trauma] is hidden, but it’s still there,” he said.