Aaron Ybarra appears in court at the King County Jail in Seattle, Washington June 6, 2014. REUTERS/David Ryder If there's one problem in the United States more pressing than the staggering number of adults suffering from mental illness, it's the fact that nearly half of them aren't getting treatment for it.

According to Mental Health America's recently released annual assessment, about 20% of U.S. adults — or 43.7 million people — have a mental health condition of some kind — and less than half of them are receiving the care they need.

Among children and adolescents, the news is worse: Though the incidence of depression is on the rise, 80% of the young people afflicted receive inadequate care or none at all, according to the MHA report.

"Once again, our report shows that too many Americans are suffering and far too many are not receiving the treatment they need to live healthy and productive lives," Paul Gionfriddo, president of Mental Health America, said in a statement, according to the Washington Post.

"We must improve access to care and treatments, and we need to put a premium on early identification and early intervention for everyone with mental health concerns."

Patients are locked in a room at a mental hospital in Banda Aceh December 12, 2012. Reuters

Judging by the resources states currently have in place to treat people with mental illnesses, those seeking to improve access to care have their work cut out for them.

The nonprofit's report ranked all 50 states and the District of Columbia on their availability of mental health treatment, and found that most states are sorely lacking available options — particularly in the Deep South.

"This is ultimately about the policy decisions we make," Gionfriddo said, according to the Washington Post. "It isn't just about what states are red and what states are blue. ... But political environments in states do seem to matter. Those that invest more in mental health clearly have to throw away less money on jails and prisons."

Of the 10 states offering the least access to mental health treatment, six top the list for having the highest incarcerations rates. In Arkansas, Mississippi and Alabama, more than 57,000 of the men and women behind bars have some sort of mental health issue.

Faring the best were three states in New England: MHA ranked Connecticut, Massachusetts and Vermont as the states with the lowest incidence of mental illness and the most accessible mental health treatment.

Gionfriddo said that he believes every state should make establishing quality care for those suffering from mental illnesses a priority, and do so immediately.

"It's time to act," he said. "We must invest in the overall physical and mental well-being of our citizens — every day."