State mental health parity laws: cause or consequence of differences in use?

A new wave of state and federal legislation affecting mental health insurance was passed during the 1990s. Although patient advocacy groups have hailed the passage of numerous parity laws, it is unclear whether this activity represents a major improvement in insurance benefits or significantly increases access to mental health care. We investigated this issue with data from two new national studies sponsored by the Robert Wood Johnson Foundation. We found that states with below-average utilization were more likely to enact state legislation, but utilization in those states continues to lag behind the rest of the nation.