WASHINGTON — After more than a decade of struggle, the House on Wednesday passed a bill requiring most group health plans to provide more generous coverage for treatment of mental illnesses, comparable to what they provide for physical illnesses.
The vote was 268 to 148, with 47 Republicans joining 221 Democrats in support of the measure.
The Senate has passed a similar bill requiring equivalence, or parity, in coverage of mental and physical ailments. Federal law now allows insurers to discriminate, and most do so, by setting higher co-payments or stricter limits on mental health benefits.
"Illness of the brain must be treated just like illness anywhere else in the body," said Speaker Nancy Pelosi, Democrat of California. Supporters of the House bill, including consumer groups and the American Psychiatric Association, said it would be a boon to many of the 35 million Americans who experience disabling symptoms of mental disorders each year.
Insurers and employers supported the Senate bill. Many opposed the House version, saying it would drive up costs.
President Bush endorsed the principle of mental health parity in 2002. But on Wednesday, the White House opposed the House bill, saying it "would effectively mandate coverage of a broad range of diseases."
Both bills would outlaw health insurance practices that set lower limits on treatment or higher co-payments for mental health services than for other medical care.
Typical annual limits include 30 visits to a doctor or 30 days of hospital care for treatment of a mental disorder. Such limits would no longer be allowed if the insurer had no limits on treatment of conditions like cancer, heart disease and diabetes.
The Congressional Budget Office estimated that an earlier version of the House bill would increase premiums for group health insurance by an average of four-tenths of 1 percent. Some of the cost could be passed on to workers.
The House bill does not apply to health plans sponsored by an employer with 50 or fewer employees. Nor does it apply to coverage in the individual insurance market.
Three factors contributed to support for the legislation. First, researchers have found biological causes and effective treatments for numerous mental illnesses. Second, a number of companies now specialize in managing mental health benefits, making the costs to insurers and employers more affordable.
Finally, some doctors say that the stigma of mental illness has faded as people see members of the armed forces returning from Iraq and Afghanistan with mental disorders.
Supporters of mental health parity see it as a civil rights issue, and the debate Wednesday was filled with poignant moments.
"I have a mental illness, and I am fortunately getting the best care this country has to offer because I am a member of Congress," said Representative Patrick J. Kennedy, Democrat of Rhode Island and chief sponsor of the House bill. Mr. Kennedy has been treated for depression and drug dependence.
The main Republican sponsor, Representative Jim Ramstad of Minnesota, a recovering alcoholic, said, "I am living proof that treatment works and recovery is real."
The House bill is named for Senator Paul Wellstone, the Minnesota Democrat killed in a plane crash in 2002. He had a brother with severe mental illness. The main sponsor of the Senate bill, Pete V. Domenici, Republican of New Mexico, has a daughter with schizophrenia.
Under a 1996 law, health plans are forbidden to set annual or lifetime dollar limits on mental health care that are lower than the limits for other services. But insurers have gotten around the law by setting different limits on the number of outpatient visits or hospital days, and by charging different co-payments.
The protections of the House bill apply to people who need treatment for alcohol and drug abuse, as well as mental illness.
Under the bill, if an insurer chooses to provide mental health coverage, it must "include benefits" for any mental health condition listed in the latest edition of the Diagnostic and Statistical Manual of Mental Disorders, published by the American Psychiatric Association.
E. Neil Trautwein, a vice president of the National Retail Federation, a trade group, said: "Businesses will be faced with the choice of covering every single mental or substance abuse disorder listed in the diagnostic manual, or nothing at all. Neither choice is appealing."
Among the conditions listed in the manual, critics noted, are caffeine intoxication and sleep disorders resulting from jet lag.
Nicholas M. Meyers, director of government relations at the American Psychiatric Association, said: "This is nonsense. Simply because a diagnosis is made does not obligate insurers to pay for treatment."
Insurers could still deny coverage if they found that a service was not medically necessary.