Several recent reports shed some light on violence and substance abuse among mentally ill patients after release from treatment facilities.

• According to a report published in the Archives of General Psychiatry, mental patients discharged from a hospital stay are no more violent than other members of the community unless they have been abusing alcohol or drugs.

• Substance abuse increased the rates of violence of mental patients by up to five times -- compared to a tripling in the rate of violence by other people.

• The mentally ill are almost twice as likely as other people to be alcoholics or on drugs.

• The types of violence committed by the mentally ill are largely the same that other people commit, but more than 85 percent of their violence is directed against family members or friends, versus only 14 percent against strangers.

Some experts estimate that the mentally ill are responsible for about 1,000 homicides a year in the U.S. But such estimates are controversial. Other experts believe that the mentally ill are responsible for about 4 percent of overall violence.

The new findings that the mentally ill may be more violent in some circumstances challenge long-held beliefs among mental health professionals than victims of mental illness are no more violent than anyone else.