The dependent coverage mandate of the Affordable Care Act went into effect in September 2010.  It allowed young adults to remain on their parents’ health insurance as dependents and applied to most individuals age 19-25.  This is the first study to examine the effect of the mandate within a nationally-representative population of young adults with possible behavioral health disorders.  We hypothesized that the mandate would significantly increase use of both mental and substance use treatment, reduce out-of-pocket spending, and shift treatment to settings that are more difficult for uninsured individuals to access.  Using repeated cross-sections from the 2008-2012 National Survey of Drug Use and Health (NSDUH), we examined trends in use of any treatment and, conditional on using treatment, setting and payer source.  We applied validated screening measures and defined two subsamples: individuals with possible mental health disorders and individuals with likely substance use disorders.  In difference-in-differences (DD) analysis, we compared trends before and after the mandate among young adults (age 19-25) to older adults (age 26-36).  Regression models adjusted for individual-level sociodemographic characteristics.

Our DD models reveal that, relative to older adults, use of mental health treatment increased by 5.9 percentage points among young adults with possible mental disorders after the mandate.  This increase was large compared to the pre-treatment mean of 31.6% (equivalent to a 19% increase).  Relative to older adults, young adults using mental health treatment in the prior year were 10.8 percentage points more likely after the mandate to have previous treatment paid for by private insurance, and were significantly less likely to have their treatment paid for without insurance (either self-pay or uncompensated care).  Contrary to hypothesis, there were no significant differences among individuals using mental health treatment in the type or setting, nor in the percent with private insurance who said that their coverage included mental health treatment.  By contrast, we find that the mandate had no significant effect on use of substance abuse treatment among young adults with possible substance use disorders.  In terms of payer source of those individuals using treatment, the broad trends were toward an increase in payment from both private and Medicaid and less uncompensated care among young adults relative to the older comparison sample, but these estimates were not significant at the P<.05 level.  The one significant change was that privately insured young adults were significantly more likely (13 percentage points) to report their plan included drug and alcohol treatment after the mandate relative to older adults.

In summary, the dependent coverage mandate significantly increased mental health treatment, and reduced uninsured care, among young adults with possible mental health problems, but did not significantly increase substance use treatment.  Findings highlight the possible impact that other coverage provisions of the Affordable Care Act may have on use of behavioral health treatment, especially when combined with the 2008 federal parity law.  To be effective, these interventions will require adequate supply of providers willing to accept new adults for treatment.