WASHINGTON - Most U.S. medical schools offer their students poor health insurance coverage for the treatment of mental health and substance abuse disorders, a practice that imperils the well-being of our nation’s future doctors and their patients, a group of Boston-area researchers report in JAMA, the Journal of the American Medical Association, today.

In the first study of its kind, the researchers – most of whom are faculty physicians at the Harvard-affiliated Cambridge Health Alliance (CHA) – found that fewer than 22 percent of the 115 medical schools they studied provided their students with complete coverage, without co-pays or coinsurance, for mental health and substance abuse treatment.

Some student health plans require co-payments of $20-$25 per outpatient visit and up to $500 per inpatient stay. The median coinsurance rate (the percentage of total costs paid by the patient) was 20 percent, meaning that a single course of treatment might cost a medical student thousands of dollars out of pocket.

“Research shows out-of-pocket costs discourage patients from getting mental health and substance abuse treatment,” said Dr. Rachel Nardin, assistant professor of neurology at Harvard Medical School, chief of neurology at CHA and lead author of the study.

“Everyone, including medical students, deserves full access to all needed care,” she said. “As an aside, it’s worth noting that only single-payer health systems have been able to assure such unhampered access. Private-insurance-based systems fail miserably on this score, as we see in this instance.”

A majority of schools’ insurance plans had annual limits on visits and/or total expenditures for mental health and substance abuse treatment. The plans varied considerably in this regard, Nardin said. At least one plan limited annual coverage for outpatient substance abuse care to $800, while another covered the same services up to $200,000 per year.

“In many cases the maximum dollar benefits can be very low,” she said. The number of patient visits allowed by the plans was also quite variable, ranging from 8 visits to 150 visits annually.

Senior author Dr. J. Wesley Boyd, assistant clinical professor of psychiatry at Harvard Medical School, said: “Medical students experience higher levels of psychological distress than their peers, including depression and suicidality. Such distress correlates with decreases in empathy and altruism among medical students and with increases in medical errors in doctors in training.

“Given that medical students are often leery about seeking treatment in the first place, requiring students to pay huge co-payments or coinsurance for mental health or substance abuse treatment might foreclose obtaining needed psychiatric care,” he said. “This is bad for the students and bad for patients.”

Boyd noted that many ailments persist into later years, so ensuring the ability to receive early treatment is essential.

The authors urge U.S. medical schools to “move immediately to improve student insurance coverage for mental health and substance abuse disorders.” Nardin added: “The best remedy for this situation would be a national single-payer health insurance program, a program that would offer comprehensive benefits while requiring no co-pays or coinsurance. That message needs to be heard once again in Washington.”