subject: Congress Passes Mental Health Parity Bill [print this page] To receive the greatest impact from the new mental health parity requirement, the challenge remains for employers to greatly destigmatize the treatment of mental health. Kessler estimated that almost 30 percent of the U.S. population experiences some diagnosable mental health or addictive disorder within a 12 month period, but fail to seek treatment or drop out because they want to solve the problem on their own.