The percentage of psychiatrists accepting private health insurance decreased to 55 percent in 2010. In comparison, 89 percent of other physicians accepted medical coverage, according to a study published in the journal JAMA Psychiatry.  

Though more insurance companies will soon be required to cover mental health care -- one of ten "essential health benefits" according to federal law beginning next year -- it may not solve the essential problem: psychiatrists don't need to accept insurance, the New York Times reported.

"Even if you have good insurance that covers mental health care, you may still have a problem if there's no doctor who accepts your insurance," said the study's lead author, Dr. Tara F. Bishop of Weill Cornell Medical College in New York.

Bishop said psychiatrists are currently in high demand, and so they don't need to accept insurance payments (which are similar to payments in other medical fields) if they can make a better profit charging their own rate.

A psychiatric evaluation could take an hour or more, while a trip to one's primary physician  could be as quick as ten minutes -- meaning psychiatrists can't live as comfortable off the rates paid to other doctors.

Psychiatrists also tend to own their own practice and be its only employee, Bishop said. Thus, they don't have additional staff to work with insurance companies, a full time position in larger medical bodies.

According to Dr. Steve. S. Sharfstein, a former president of the American Psychiatric Association, psychiatrists have more freedom to accept medical coverage -- or less, depending how you look at it -- because intrusive investigations by insurance companies might violate doctor-patient confidentiality, according to the Times. (Sharfstein was not involved in the study).

Psychiatrists sometimes offer deals depending on the patient's finances, according to Sharfstein, though not to the degree of an insurance plan and its $20 so co-pay would.

"Many psychiatrists do not take insurance," said Sharfstein. "They have an out-of-pocket practice. They charge what they can, but they are flexible and will set rates on a sliding scale."

Difficulties in arranging mental health care for Bishop's patients sparked the study, according to the Times. She believes the downward trend could compromise the new health law, even as Obama has slotted $50 million towards mental illness and addiction.

"These low rates of [insurance] acceptance may affect recent calls for increased access to mental health services, and if the trend of declining acceptance rates continues then the impact may be even more significant," Bishop and her fellow researchers wrote

"In the wake of the school killings in Newtown, Conn., and other recent mass shootings, the need for increased mental health services is now recognized. But unless patients have deep pockets, they may have a hard time finding a psychiatrist who will treat them," said Bishop.