Up to one in three Medicaid expansion enrollees received outpatient behavioral health treatment in 2014 in four states examined by the Government Accountability Office: Iowa, New York, Washington and West Virginia. Officials in the three states expanding Medicaid to this population for the first time said enrollees could more easily access treatment compared to the uninsured. Psychotherapy and diagnostic services were the most commonly used services, while antidepressant medications were the most commonly used drug. Medicaid is the nation’s largest source of funding for behavioral health treatment, the report notes. The study was requested by House Energy and Commerce Committee Ranking Member Frank Pallone (D-NJ) and members Diana DeGette (D-CO) and Joseph Kennedy III (D-MA).