Washington – A number of American psychologists ruled out the possibility that religion might be the main motive for the American Islamists extremists who used violence, especially those who said they are ISIS followers. These experts said that a huge number of them suffer psychological problems and cultural contradictions or even a failure in life.

John Cohen, a criminal justice professor at Rutgers University and the former counterterrorism coordinator at the U.S. Department of Homeland Security, told Asharq al-Awsat that many of them have psychological and behavioral characteristics in common.

“Some studies reveal that they suffer dangerous psychological and personal problems regardless of their religious motives or identities such as moving from one job to another or difficulty making friends,” said Cohen.

On Friday, Washington Post newspaper published cases of extremist American Muslims who refuge to violence since 2001. “Detectives see that the aggression might have been related to extremist Islamic ideologies,” said the newspaper.

Many of the cases involved people who showed signs of psychological or behavioral problems. For example: Nidal Hasan, the U.S. Army psychiatrist who killed 13 people in a 2009 shooting rampage at Fort Hood in Texas, was described by co-workers as aloof, paranoid and isolated.

Naveed Haq, a Muslim man who converted to Christianity not long before he shot six women at the Seattle Jewish Federation in 2006, had been diagnosed as bipolar and long been angered by women who were not romantically interested in him.

Alton Nolen, who in 2014 beheaded a co-worker in Oklahoma, appeared to have been obsessed with beheadings, investigators said.

Wasil Farooqui, who last month stabbed two people in Virginia, told police that he was hearing voices.

Mohammad Abdulazeez, who killed five people in a shooting rampage at military recruitment centers in Chattanooga, Tenn., suffered from severe depression, suicidal thoughts and drug abuse.