What makes people legally incompetent?

People who have committed crimes are sometimes judged to be not competent to stand trial because of their mental-health problems. Researchers from the City University of New York reviewed 68 studies carried out between 1967 and 2008 to determine which factors were most closely linked to being found incompetent to stand trial. The trials included a total of 26,139 people. Defendants diagnosed with psychosis were eight times more likely to be found incompetent and unemployed defendants twice as likely. The likelihood of being found incompetent was also double for defendants with a previous psychiatric hospitalisation. Those found to be incompetent were slightly older, mostly non-White and unmarried.