CH1YO
A little knowledge is a dangerous thing.
Also arming yourself on the basis of self destructive ideation sounds like a bad idea.
I agree with this; with mental illnesses being brought not into the spotlight but further into the public gaze (under the banner of tolerance, education and accommodation) it's difficult to avoid all knowledge. You absorb scraps of knowledge and no matter how correct a scrap may be it's incomplete. It damn near doubles the necessity to get a professional diagnosis.
I thought I knew about bipolar disorder when I was 13 (blame a children's book). Then I thought I knew about bipolar disorder when I was 18. Now I think I know a bit more about bipolar disorder. I might even go so far as to say, in my patchy ignorance, I might be able to emphasise with a Bipolar II diagnosis. But I don't have it, and frankly I don't want it.
Though I'm no poster child, a little maturity and coaxing some objectivity out of yourself is a good way to stop yourself 'hoping you have' a disorder/illness/syndrome which I feel is a legitimate factor in self-diagnosis - forgive me for being anecdotal but I've been there. It gives you a sense of validity, it authenticates how bad you are feeling and gives you something to lean on.
Unlike knowing how to spot signs of physical disease before it fully manifests, learning in part how your mental health is functioning is a bad idea. The mind is fluid and will twist under observation, and will twist further (in corresponding or contradictory extremes) under expectation and it is not entirely due to subconscious processes. You might not want to mention the extra bottle of wine on Sunday to the vicar, or you might want to make sure the coach knows that you scored the decisive point that match, and you might want the doctor to think that you are hearing voices more and more and more; you have lied, you have dismissed other contributors, you have exagerrated. Objectivity is sometimes in short supply.