it was really more that they wanted to use thorazine and such as a chemical straight jacket and charge the government thousands of $$$ per patient each month.
members of congress got filthy rich off the Rx industry and the streets filled up with crazy folks. the thing is many don't take their meds correctly and on top of that the side effects can cause even worse mental problems.
congress/the medical/RX industry and wall-street are joined at the hip. it is much more easy and politically correct to blame firearms than thir own failed policys and get rich quick laws they enacted.