The American Psychological Association (APA) has approved a ban on psychologists' involvement in national security interrogations.

The group approved its new ethics guidelines Friday in Toronto. The APA adopted the plan in the wake of 542-page independent investigation (PDF) that discovered psychologists worked with the Central Intelligence Agency to help silence dissent over harsh interrogation tactics being employed by the Bush administration (including torture). What's more, the report found that APA officials colluded with military officials to adopt APA ethics rules in order to allow psychologists to be a part of tortuous interrogations in the wake of the September 11, 2001 terror attacks.

Psychologists' involvement in torturous interrogations aided the President George W. Bush administration's assertions that the techniques, such as waterboarding, were legal. That's because having psychologists involved in interrogations helped the Justice Department draw up secret legal opinions saying that harsh interrogations were OK—and not torture—since health officials were taking part.

In a 2010 interview, for example, Bush said: "Another technique was waterboarding, a process of simulated drowning. No doubt the procedure was tough, but medical experts assured the CIA that it did no lasting harm."

According to Friday's resolution, psychologists "shall not conduct, supervise, be in the presence of, or otherwise assist any national security interrogations for any military or intelligence entities, including private contractors working on their behalf, nor advise on conditions of confinement insofar as these might facilitate such an interrogation."

The group announced that the policy "does allow for psychologist involvement in general policy consultation regarding humane interrogations. The prohibition does not apply to domestic law enforcement interrogations or domestic detention settings where detainees are under the protection of the US Constitution."

Susan H. McDaniel, the group's president-elect, said the move is a cultural shift.

"We have much work ahead as we change the culture of APA to be more transparent and much more focused on human rights," she said. "In addition, we will institute clearer conflict-of-interest policies going forward, all of which are aimed at ensuring that APA regains the trust of its members and the public."

Psychologists could face ethics complaints for continuing to assist in interrogations. Under the resolution passed Friday, the APA will send a letter to President Barack Obama requesting that psychologists not participate in interrogations at Guantanamo Bay or other places, known and unknown, where national security interrogations are taking place.

President Obama barred the use of torture in interrogations with a 2009 executive order.