When more than half of people who need mental health care can’t or don’t get it — as is true in the U.S. — other problems arise. For sufferers, these include physical illness, lost earnings, substance abuse and suicide. For society, there is greater crime and homelessness.

So legislation in the House of Representatives meant to expand mental health care is welcome. The bill, which could soon get a vote, would give mental health issues more weight within the Department of Health and Human Services and improve tracking of wait times for psychiatric beds. It would also provide small grants for suicide prevention, for educating new psychologists, and for training police to better engage with the mentally ill.

And it would remove various restraints on mental health care — for instance, an anti-fraud restriction that prevents Medicaid from paying for two services at the same location on the same day. This rule has kept many people from getting treatment for depression as part of a regular checkup.

Yet mental health services in the U.S. are so inadequate that these changes would still leave many Americans without the care they need.

In the past two decades, mental health services have been shrinking, not growing. From 1992 to 2012, the number of psychiatric beds per capita fell by two-thirds, to just two for every 10,000 people. The U.S. is the only affluent country where the number of psychiatrists per capita fell from 2000 to 2011, even as it spends twice as much as others on health care.

To expand psychiatric care as much as is needed would necessarily increase that spending. Federal money is required to pay for more treatment via Medicaid and Medicare.

For example, the legislation wouldn’t change Medicare’s 190-day lifetime limit on inpatient psychiatric care. That’s especially restrictive for working-age adults on disability; better access to care could help people with mental illness rejoin the workforce. And the law would still limit Medicaid’s ability to pay for inpatient adult psychiatric care.

Sponsors of the House legislation note that their approach won’t add to the federal budget; that may be what it takes to get any bill through this Congress. Certainly, more federal spending isn’t the only way to fill the mental health gap. The legislation will push private health insurers to adequately cover mental illness, as well.

But wider coverage by government health plans is still needed. Adequate spending on mental health would save other social and government costs down the road. Left untreated, mental illness drains the public purse one way or another.