Should health insurance policies be required to cover mental illness with the same level of benefits as they do physical ailments like cancer and heart disease?

The Senate put the controversial issue into play last week when it unexpectedly added such a requirement to a bill it passed that would allow employees to keep their health-care coverage when they change jobs or are fired. The Senate vote was 100 to 0.

The boundaries between neurologic, psychiatric and psychological problems--all of which can affect behavior--are still sometimes blurry, although less so than in the past. Treatment can range from urgently needed medications to relieve biochemically-based suicidal depression or acute psychosis to long-term psychotherapy to alleviate the effects of childhood emotional trauma, the effectiveness of which can be difficult to prove by scientific standards. Most health insurers and employee health plans do discriminate against mental disorders. Hospital coverage is usually less than for other illnesses. Patients' co-payments for hospitals, doctor bills and therapy are often larger. Increasingly, some of the large corporations which cover behavioral problems are using for-profit managed-mental-health-care plans that are sharply squeezing down costs and services.