Well actually a diagnosis if PTSD is expected to go away.  It usually does on its own I think.  It's not chemical, it's a situational thing and a lot of people just get over it.  Something like bipolar or schiozophernia is supposed to be biochemical - you were born with it although often it doesn't materialize until puberty when the hormones kick into gear.  So those don't go away but can be "managed" with therapy and medication like diabetes.  Have you gotten that lecture?  The "this is like diabetes so take the insulin/medication"?  PTSD isn't a lifetime sentence like bipolar is. When they thought I had bipolar it was just "take the pills and try not to go crazy" and when they realized it was PTSD they said "Screw the pills, get therapy and work it out and go have a life."

Misdiagnosis is because there is no test for mental illness, no blood work.  They are guessing that's all.  They have a book made in 198- from one school of thought's doctors who were trying to get rid of the opinion people had that psychiatry was not a real science.  So they made the DSM to try to look like there was some standard of what is going on in the brain.  But the DSM changes all the time as they get info on brain scans and treatments.  So if you see a doctor are talking fast and not sleeping well, like I was, they say "bipolar" but now they might not because it is now known that adults have ADHD which back when I was younger they didn't know.  If you see a doctor who asked about trauma you might get a trauma diagnosis, if not, you might get a BPD diagnosis.  It's all very random.  There's no test for anything.  At all.  They are trying to pick a description that matches best what you are telling them and what they are observing.  But until women wree involved in psychology, our needs were misunderstood and misintrepreted - Freud thought women wanted to fuck their Dads and didn't know that they were victims of incest.  So the diagnosis changed when women started talking for themselves in the 70s with feminism.

So if you saw a doctor in the 1990s and got a diagnosis that diagnosis might not even be in the DSM 4!  Or as new info comes out a new diagnosis that makes more sense might be found.  And what doctor you see will determine what they look for.  So if it is a doctor who works with ADHD a lot, they'll be looking for that, but if they work with BPD they'll be looking for that.  It's not that YOU changed, it's that the symptoms they were looking for or how they explained the symptoms has changed.  Insomnia might mean Bipolar, ADHD. PTSD, generalized anxiety disorder, sleep apena - Ot could be anything.  Have you read the DSM?  It's hard to work with.  Most doctors and therapists I know say that it's pretty fictional, that no one really HAS anything in it, it's just a starting point.  I don't think I have seen anyone in a few years that thinks that diagnosis is for anything besides insurance companies actually.  You have to tell insurance what is wrong with someone to justify the money.  Depression is not a good reason for them to spend money on therapy forever, but bipolar is because therapy for bipolar is cheaper than hospitalization, so a bipolar diagnosis gets you insurance paid for therapy.  So if you are wanting better services, it can help to have a worse diagnosis.

It is not like you have cancer or allergies or an ear infection. There's no test and no way to really know what is happening biochemically.  it's all guess work.  Nothing else.  They just try every drug they can and hope to God that something works, nothing more.  They really have NO IDEA what drug will help either, sonce everyone is different.  I had thought that you get a DSM diagnosis and then that tells them what drug and therapy will fix me.  Nope.  It just gives them an idea of what symptoms you have. nothing more.  There are no gauerentees.  So you have to have a pretty hopeful atttitude of nonattachment.  Try everything til something works and then do that.  It would be nice if there were people who had a cure but there are not.  In the 1990s PTSD was supposed to be cured with regression therapy - Now they know that retraumatizes people and makes it worse.  So maybe this CBT stuff will be shown to not work longterm one day.  Who knows? 

I guess we have to not get hung up on getting "better".  It just is what it is.  Find ways to live with it as best you can, but know your way is going to be different than anyone else's. 

They do not know what causes these "mental illnesses".  It's all theory.  But as they look at brain scans,. they are starting to see what happens and that's helpful.  A brain scan would show you being triggered for instance.  Bipolar has been described since the Greeks, so it proably does exist as a biochamical thing.  ADHD was never described until the 1950s so it might be that until kids had to sit in classrooms, no one noticed it, or maybe it is created by pesticides or something in the water or womb?  PTSD has been described by all cultures from time immeorial when describing soldiers - our culture called it shellshocked for WW2.

The brain is just very complicated and wired very delicately.  They do not understand it.  So keep in mind it is all theory. 

Also - most psych freshmen in college diagnosis themselves with EVERYTHING they read about - it is normal to do that.  And most therapists become therapists because they had some issue they got help with from therapy and hence can often project it onto you if they aren't a good therapist.  I have that happen a lot.  Therapists usually have the most messed up childhoods there are.

"When I tell the truth, it is not for the sake of convincing those who do not know it, but for the sake of defending those that do." -William Blake