(Bigstock)

As Hillary Clinton rolled out her mental health policy proposals this week, the nation is confronting a mystery regarding access to care. The past decade has witnessed a flurry of federal legislation intended to improve coverage of mental health treatment within private and public sector insurance plans. Why then do research studies continue to document that even people with health insurance often have difficulty finding a psychiatrist? Two new studies of the state of the psychiatric profession help explain this frustrating situation.

A study led by Professor Tara Bishop of Weill Cornell Medical College calculated changes in the number of physicians engaged in different types of practice from 2003 to 2013. The number of adult primary-care physicians increased by 9.5 percent and the number of neurologists increased by 35.7 percent. In contrast, the number of psychiatrists declined by 0.2 percent, which represents a 10.2 percent drop in availability when the decade’s population growth is taken into account.

An optimist might respond that, even though it’s harder to find a psychiatrist than it used to be, at least you are less likely to have to pay for treatment out of pocket because federal laws have improved the mental health coverage provided by insurance plans. For example, during the George W. Bush presidency, Congress increased Medicare’s reimbursement rates for outpatient mental health services and passed legislation strengthening benefits in insurance plans provided by large employers. Under President Obama, the Affordable Care Act of 2010 built on these reforms by defining mental health as an “essential health benefit” in the Medicaid expansion and in private plans sold on health exchanges.

However, another study by Bishop’s team found that although almost all non-psychiatric physicians accept private or public insurance, only about half of psychiatrists do so. Improving mental health insurance benefits thus isn’t going to make finding a psychiatrist much easier in the short-term, even though it may help in the long-term by tempting more psychiatrists to start accepting insurance.

Why don’t more psychiatrists accept insurance? In part it’s because they don’t have to: As members of a small and shrinking profession, they are much in demand and can therefore often keep their practices full on a cash-only basis. The hassles of dealing with mental health insurance plans may also be a factor. Mental health services are often “carved out” of health insurance plans to separate companies that manage benefits very tightly, requiring extra paperwork and (uncompensated) time to receive authorization and payment for care. Although the new federal laws were supposed to lessen these bureaucratic barriers to psychiatric treatment, compliance by insurers has been uneven. Indeed, New York State Attorney General A.G. Schneiderman’s investigations into improperly denied mental health care have led to fines and revisions of claims review procedures by insurers such as ValueOptions, Excellus and Emblem Health.

New York’s experience shows that enforcement is sometimes necessary to deliver the promised benefits of recent federal mental health insurance laws. Similar enforcement actions on the federal level — which Hillary Clinton has pledged to undertake if elected president — could pressure more insurance companies to provide mental health benefits at parity with other health benefits, as federal law now requires. If policies mandating better compensation rates and fewer insurance hassles are in fact fully implemented, it should incline more psychiatrists to accept insurance, which in turn should increase access to care for individuals and families facing serious mental illness.

More from Wonkblog:

A shocking number of mentally ill Americans end up in prison instead of treatment

Researchers' latest weapon in the fight against mental illness? Twitter.

Few people realize this big risk when they go to the hospital