Access to mental health providers and medication has dropped, a new study says, although federal lawmakers have enacted legislation in recent years to bolster private and public coverage of mental health treatment.

The findings were assembled by researchers from New York University’s Langone Medical Center, who published details of their report online Monday in the journal Psychiatric Services. Using data from the Centers for Disease Control and Prevention, they found that the incidence of people who report having a form of serious psychological distress, such as anxiety or depression, has increased to about 3.4 percent of the U.S. population, which comes to 8.3 million adults. Previous estimates had pinned the number closer to 3 percent.