Is wanting to kill yourself always a mental illness?

There's a scientific debate about this. Well, a debate that's as
scientific as anything in mental health.

Some people believe that suicide is only a sign of mental illness. There
can be no rationality because they can't understand the ration. Others,
for example Edwin Schneidman (a suicidologist who pioneered and drove
forward the study of suicide through suicide notes), believed not every
suicide is because of mental illness.

Thankfully the Swiss clinic Dignitas favours Schenidman's theory. At
last I can die without having to chose a shitty method.

Differentiating from a rational and irrational suicidal desire is
difficult. Many psychiatrists may find this concept alien. Someone who
doesn't want to be alive must be depressed. It must be a bran illness
because life's so fucking great for them they couldn't conceive that it
might be really shit for someone else, and shit at a level where their
pathetic measures couldn't understand and their diagnostic interviews
fall short because of their absurdity and excessive simplicity in
attempting to describe the human condition.

What measure will understand that the happiest moment for me this year
is finding out the Dignitas clinic will allow someone like me to
terminate their life peacefully. It may seem crazy but it's rational to
me. I've wanted to die for most of my adult life. I've made several
attempts. I drag myself through life regardless but I don't want to.