That was the finding from a study of the effect of Oregon’s law requiring parity coverage of mental illness and substance abuse treatment. The study, appearing online in AJP in Advance, found that increases in spending on mental health and substance abuse services after implementation of Oregon’s parity law were almost entirely the result of a general trend observed among individuals with and without parity. Expenditures per enrollee for mental health and substance abuse services attributable to parity did not differ significantly from zero in any of the four health plans that were studied.
That finding is significant because Oregon’s parity law is unique among state parity laws in that it requires that “non-quantifiable treatment limits”—that is, various restrictions on utilization of services—cannot be more restrictive for mental illness and substance abuse than for general medical and surgical care.
The study of Oregon's parity law follow-up is online at http://ajp.psychiatryonline.org/cgi/reprint/appi.ajp.2011.11020320v1. And for additional coverage of parity and legal battles around treatment limits in the federal parity law see Psychiatric News at http://pn.psychiatryonline.org/content/45/9/1.1.