SALEM, Mass. — Attorney General Maura Healey says a North Andover-based drug treatment center illegally charged patients hundreds of dollars in cash for opiate addiction treatments the state's low income health program covers.Healey said a civil complaint was filed Wednesday in superior court in Salem against the Center for Psychiatric Medicine.She said beginning in 2010, CPM told new patients the MassHealth program didn't cover treatment using the anti-addiction drug Suboxone.