Professor Jeffrey Lieberman discusses the serotonin hypothesis of schizophrenia. Drugs such as LSD and ecstasy block serotonin and produce schizophrenia-like symptoms.
The third neurochemical hypothesis of schizophrenia is the serotonin hypothesis. And this, like the dopamine and the glutamate hypotheses, derived, in part, from observations about the pharmacology of drugs that were used recreationally, specifically hallucinogenic or psychotomimetic drugs, like LSD, mescaline, psilocybin, ecstasy. These drugs all acted by blocking the affects of serotonin at specific receptors and therefore it was reasoned that if it can produce these amazing changes in the mind and mental processes and behavior, then maybe internal processes in the brains of people with schizophrenia were occurring that were producing the symptoms of the illness.