Are there any relation between dopamine and schizophrenia?

Please teach me this:
Are there any relations between dopamine and schizophrenia.What is the role of blood-brain barrier in protecting brain from schizophrenia by dopamine(it seem to me dopamine is agent causing schizophrenia).If blood-brain barrier is not in good condition,how could we rescue it?
Thank you very much in advanced.

[ILADVOCATE]

    Dopamine in all people including people with schizophrenia is a normal neurotransmitter (one of many) that works in a variety of areas of brain functioning. In a person with schizophrenia according to current theories the level of activity of the dopamine receptors is too high and this is one cause of psychosis so current antipsychotics lower the amount of activity of the dopamine receptors. It is not an issue with the blood brain barrier and dopamine is always present and part of brain functioning not something to protect a person from. However as research has found there are other receptors involved than dopamine and they are developing new classes of antipsychotics based on these theories.
   One of them are the Nmda Receptor modulate antipsychotics which increase the amount of glutamate transmission as that has shown to be too low in people with schizophrenia and that might be another cause of psychosis (it adds to current theories, it doesn't replace them). You could find out more about that using the search phrase "A New Class of Antipsychotics in Development". As for how currently available antipsychotics work there are books and websites that can explain this that can be of help such as the book "Surviving Schizophrenia". The organization NAMI has some good informational literature as well. All this could be discussed with a psychiatrist.

[paranoid_cataclysm]

Yep, ILADVOCATE is right; dopamine is a normal neurotransmitter in all brains and in current theories the people with schizophrenia have too much dopamine activity one way or another.

[drifter0213]

so is schizophrenia a chemical imbalance?

[paranoid_cataclysm]

That's what I'm told.

[ndung200790]

Thank ILASVOCATE very much!