More young adults are getting inpatient mental health treatment with expanded coverage under the Affordable Care Act, also called Obamacare. But the demand has exposed a weakness in the system’s ability to deliver cheaper outpatient care, according to researchers at Indiana and Purdue universities.

The ACA requires health insurers to cover adult children younger than age 26 on a parent’s group plan, eliminating an insurance gap common for young adults attending school or entering America’s workforce. Moreover, the new health law has expanded coverage to young adults in other ways, according to a study published in the journal Health Affairs. Enrollment in health policies grew 6.7 percentage points from September 2010 to 2011, with much of the gain among single working adults, particularly men.

“Analysis of the timing of the policy impact suggested that early gains in coverage were greatest for people in worse health,” wrote Benjamin D. Sommers, an assistant professor at Harvard University who advises the Department of Health and Human services on policy.

In these latest findings on the new law’s impact, researchers Kosali Simon and Asako S. Moriya of Indiana University, along with Yaa Akosa Antwi of Purdue University, say that inpatient usage rates rose 3.5 percent among adults aged 19 to 25, compared to adults aged 27 to 29. Most of that increase went to mental health visits, which rose nine percent with increased health coverage. And among those young adults, community hospitals across the U.S. surveyed for the study reported a 12.5 percent decrease in patients without health insurance.

The uptick in patients seeking mental health services was not seen among young adults in Massachusetts after the state implemented an earlier version of health insurance reform in 2006, according to an April study in JAMA. Among 19- to 25-year-olds in Massachusetts, the rate of uninsured fell from 26 percent to 10 percent, but usage of inpatient mental health services fell slightly following expanded coverage. Compared to Maryland that year, the increase in emergency room visits for behavioral health diagnosis was lower among young adults.

Regardless of the national increase in mental health inpatient usage, Simon and her colleagues found no evidence that the quality of services had decreased with expanded demand for services.

"We eventually judge all these [insurance] expansions based on the final outcomes that we care about," Simon wrote on the National Bureau of Economic Research's website. "How did this affect the well-being of young adults? Is there a measurable improvement of health status? Does it appear that there is better mental health as a result of this increase?"

Those questions will surely be answered soon enough. 

Source: Antwi, Yaa Akosa, Moriya, Asako S., Simon, Kosali. Access to Health Insurance and the Use of Inpatient Medical Care: Evidence from the Affordable Care Act Young Adult Mandate. The National Bureau of Economic Research. 2014.