Misdiagnosis between Multiple Personality Disorder, Schizophrenia, and Bipolar Disorder?

What might be the downside/disadvantages if MPD, Bipolar, or schizophrenia is not treated or misdiagnosed since they have similar symptoms and can get confused with one another?

this could get very long, so I am just going to say this. (Especially Bipolar, where you get extreme highs [mania] and extreme lows [depression]) can be very dangerous to the person and anyone around them. Mania can cause a person to do extreme things, they move and think very quickly with very extreme mood changes. They also do not think rationally, therefore there judgement is seriously impaired. The 'act before they think' and often do not feel remorse because they either do not understand what they did or they are thinking to far ahead to care. The lows (depression) of all of these disorders can lead to suicidal or homicidal thoughts. Schizophrenia often comes with auditory hallucinations and delusions. This can frighten the person and often convince them to do harm to themself or others if that is what 'the voices' tell them to do.
This is a huge topic and I could go on for hours and pages of this...but I think you kind of get the general point I am trying to make here. Any more questions, go ahead and email me, I will answer.

Well if you're treating the wrong disorder it's likely to be ineffective.

But they are pretty different.

MPD is a dissociative disorder where people can switch between 2 or more personalities.

Bipolar Disorder is just a flip flopping between depressive states and manic states - no different personalities.

And there are no different personalities in schizophrenia either. It's a really complicated disorder that is suspected to have a biological basis (these people have very different brains). Some symptoms might be hallucinations, paranoia, reacting emotionally inappropriately (laughing at a funeral). There are a few different types of schizophrenia.

Here's more info:
http://en.wikipedia.org/wiki/Schizophren...