Personality disorders aren’t mental illnesses. They have to do with your personality, not your brain. I also don’t see how eating disorders are a mental illness. Substance abuse disorder itself isn’t a mental illness. Doing drugs doesn’t always mean someone is mentally ill, even though many mentally ill people do drugs. And things like impulse control disorders and conduct disorders are just disorders to excuse bad behavior, unless the person is autistic or have something like Tourette’s.