"Another reason some people believe it is ethical to interfere with a person's right to think about or commit suicide is belief in mental illness. But a so-called diagnosis of "mental illness" is a value judgment about a person's thinking or behavior, not a diagnosis of bona-fide brain disease. So-called mental illness does not deprive people of free will, but on the contrary is an expression of free will"

http://www.antipsychiatry.org/suicide.htm