There is also some evidence that brain immune response produces the symptoms of alcohol and drug use...
Immune abnormalities in patients with psychosis have been recognized for over a century, but it has been only relatively recently that scientists have identified specific immune mechanisms that seem to directly produce symptoms of psychosis, including hallucinations and delusions.
This 'immune hypothesis' is supported by new work published by Pathmanandavel and colleagues in Biological Psychiatry. They detected antibodies to the dopamine D2 receptor or the N-methyl-D-aspartate (NMDA) glutamate receptor in a subgroup of children experiencing their first episode of psychosis, but no such antibodies in healthy children. Both are key neural signaling proteins that have previously been implicated in psychosis.