Prisoners who endure poor or degrading treatment suffer much of the same long-term psychological distress as do captives who are tortured, suggests a study published Monday.

Experts point to human rights abuses by the U.S. military in Guantanamo Bay, Iraq and Afghanistan, and say the findings underscore the need for a broader definition of torture.

“What is the basis for the distinction between torture and other cruel and degrading treatment? Science should inform this debate,” the study’s lead author, Metin Basoglu of the Institute of Psychiatry at King’s College in London, told The Associated Press in a telephone interview. The study was published in the Archives of General Psychiatry.

Steve H. Miles, of the University of Minnesota’s Center for Bioethics, said the findings “show that the severity of long-lasting adverse mental effects is unrelated to whether the torture or degrading treatment is physical or psychological.”

“The wrongness of these inflicted harms is compounded by the fact that most abused prisoners, including those in the present war on terror, are innocent or ignorant of terrorist activities,” said Miles, who was not involved in the study.

The Bush administration has said the U.S. uses legal interrogation techniques – not torture – to gain information that could head off terror attacks. It insists the U.S. complies with the U.N. Convention Against Torture.

Yet Washington’s definition of torture, as interpreted by the Justice Department after reports surfaced of American abuses in Guantanamo Bay, Iraq and Afghanistan, is fairly narrow.

It excludes mental pain and suffering created by acts that do not cause severe physical pain, such as blindfolding, hooding, forced nudity, isolation and deprivation of sleep or light, the researchers said, citing a Dec. 30, 2004, Justice Department memo. The document also contends that for an act to be considered torture, there must be proof that it inflicts “prolonged mental harm.”

“The implications of such a narrow definition of torture have raised serious concerns in the human rights community,” said the study. “These findings suggest that physical pain per se is not the most important determinant of traumatic stress in survivors of torture.”

The study involved interviews with 279 victims who suffered ill treatment and torture while imprisoned in the 1990s in the former Yugoslavia.

The researchers said they found that aggressive interrogation techniques, humiliating treatment, verbal abuse, threats against a captive’s family and being forced to watch an acquaintance being tortured produced much of the same long-term mental trauma as physical torture.

“Sham executions, witnessing torture of close ones, threats of rape, fondling of genitals and isolation were associated with at least as much if not more distress than some of the physical torture stressors,” they wrote.

Such experiences were just as likely as physical torture to lead to depression or post-traumatic stress disorder, said the study.

“Ill treatment during captivity … does not seem to be substantially different from physical torture in terms of the severity of mental suffering they cause,” it concluded. “These procedures do amount to torture, thereby lending support to their prohibition by international law.”