Peace of mind: mental health insurance remains elusive for many U.S. workers.(Special Report: Health Insurance)

Mental health advocates couldn't contain their praise for Maryland lawmakers five years ago.

In a proactive move aimed largely at managed care providers, the legislature passed a wide-sweeping law during its 1994 session that was designed to put mental health coverage on a par with coverage for physical ailments.

Has it worked? Are Marylanders healthier now? Has it affected the bottom lines of insurance and managed care companies?

Frankly, the answers are not clear cut. Mental health advocates say black, insurance companies say white, and the truth is probably some shade of gray.

This much is clean. Many thousands of Maryland workers still do not enjoy the benefits of the state mental health law.

That's because the so-called "parity" law does not apply to some of the state's biggest employers. Under federal insurance guidelines, firms that serf-insure are exempt from most state insurance regulations. And that can leave many workers and their families without coverage :for psychiatrists, drug rehabilitation counselors and other behavioral-health specialists, mental health advocates say.

Among a select group of self-insured firms surveyed recently by the Maryland Health Care Access and Cost Commission, only 7 percent said they offer mental health benefits equal to …