The ban means those who are American Psychological Association members can't assist the U.S. military at these sites. They can only work there for humanitarian purposes or with non-governmental groups, according to Stephen Soldz, a Boston psychologist. Soldz is founder of an ethics coalition that has long supported the ban...2008 APA Petition Resolution Ballot, Psychologists vote against role in interrogation (via Blogzilla)
Psychologists have been involved in decisions that approve of coercion methods, including "taking away comfort items like clothes and toilet paper from detainees" to help extract information from them, Soldz said.
He said that some even declined to diagnose post-traumatic stress in detainees because that would suggest detainees had been abused or harmed while in custody.
Whereas the United Nations Special Rapporteur on Mental Health and the UN Special Rapporteur on Torture have determined that treatment equivalent to torture has been taking place at the United States Naval Base at Guantánamo Bay, Cuba. 
Whereas this torture took place in the context of interrogations under the direction and supervision of Behavioral Science Consultation Teams (BSCTs) that included psychologists. [2, 3]
Whereas the Council of Europe has determined that persons held in CIA black sites are subject to interrogation techniques that are also equivalent to torture , and because psychologists helped develop abusive interrogation techniques used at these sites. [3, 5]
Whereas the International Committee of the Red Cross determined in 2003 that the conditions in the US detention facility in Guantánamo Bay are themselves tantamount to torture , and therefore by their presence psychologists are playing a role in maintaining these conditions.
Be it resolved that psychologists may not work in settings where persons are held outside of, or in violation of, either International Law (e.g., the UN Convention Against Torture and the Geneva Conventions) or the US Constitution (where appropriate), unless they are working directly for the persons being detained or for an independent third party working to protect human rights.