Can or should anything be done to protect society from violence perpetrated by the mentally ill? The recent deaths of two Capitol Hill police officers, shot by a suspect who is apparently schizophrenic, have prompted some suggestions by E. Fuller Torrey and Mary Zdanowicz of the Treatment Advocacy Center.

They make the following points:

• Victims of schizophrenia or manic-depressive illnesses who are not taking medication prescribed to control their delusions are responsible for a growing number of violent acts.

• Out of a U.S. population of some 3.5 million schizophrenics and manic-depressives, an estimated 40 percent are not receiving treatment in any given year.

• A 1990 study of families with a seriously mentally ill member reported that 11 percent of the ill individuals had physically assaulted another person in the previous year.

• A 1998 MacArthur Foundation study reported seriously mentally ill individuals committed twice as many acts of violence in the period immediately prior to their hospitalization -- when they were not taking medication -- compared with the post-hospitalization period when most of them were taking medication.

Recent studies have shown that about half of those who have schizophrenia or manic-depressive illness do not know they are sick, because their brain disease has affected the areas of the frontal lobes necessary for self-awareness. Not perceiving their illness, they do not take their medication. Under outpatient commitment statutes, 37 states can mandate that such persons take their medication, and a few other states can do so under conservatorship or conditional hospital release arrangements.

Torrey and Zdanowicz contend that federal benefits going to the mentally ill -- such as Social Security disability insurance and veterans benefits -- should be contingent on a proper medication regimen.