Coverage for Residential Treatment in Eating Disorders

This article entitled "Eating Disorders a New Front In Insurance Fight" describes the challenges that individuals with eating disorders face when trying to get coverage for residential treatment for those disorders. Even though mental health parity exists for physical and mental disorders, insurers are still finding ways to deny payment for mental health treatment. In what ways have insurance companies made it easier or harder for individuals with mental health problems to receive care? Should insurance companies be mandated to cover more "aggressive" treatment models even when they have little research on them?