Honestly though...and I think I'm going to **** some people off...

But a psychiatrist is trained to see symptoms and give out medication.
A GP can do the same thing without as much training.
Even patients can look at the list of symptoms and identify where they are on the spectrum. (Depressed /Mixed / Normal / Hypo / Manic) Though it is a lot harder to identify anything with psychosis involved.

The DSM-IV is just a list of symptoms. A psychiatrist is there to look at the symptoms and compare it to your CURRENT behavior or any PREVIOUS behavior YOU tell them. They have a very narrow viewpoint and rely on patients to understand symptoms. If they could tell by looking at you, they would never ask about past behaviors. It's SUBJECTIVE. You can EASILY lie to the psychiatrist and be prescribed x medication if you understand the disease enough and can replicate it and be misdiagnosed.

This is applicable to any doctor. Sometimes doctors themselves cannot identify the problem even if you see multiple specialist. Doctors are trained to look for specific symptoms to rule out various diseases. If you are suffering from something that is more uncommon, it's more likely that the doctor will struggle because of the availability heuristic. They know what they see more often. BP and Depression are becoming diagnosed enough that a GP would still see and prescribe enough to them. I have read various posts where the patient only sees their GP for their medication. I have read topics where patients can influence the medication given to them by a psychiatrist. My last psychiatrist always bargained with me to see what I would and wouldn't take. (She knew I read a lot about medications in general and knew I would never take a high dose for a long period of time) Doctors don't know all. They may be an authoritarian figure but we still need to be assertive in our care...and I totally went on a tangent.....

http://en.wikipedia.org/wiki/Rosenhan_experiment

This study was done in 1973. Although they have made extra efforts to prevent something like this from happening...it can still happen.

4 years ago, when I was hospitalized a girl was getting ready to be discharged. She wasn't suicidal at all, but had gotten in there to get some more stimulants along with anti-depressants.

I wouldn't totally discount the GP, but she could be making a mistake. It's worthwhile to see a psychiatrist, but don't go in there looking for a diagnosis. A therapist could probably help you too. They see you more often and have enough training to see red flags. If you're seeing a therapist and they don't think you have BP, you probably don't have it.