Serotonergic neurotransmission abnormalities

At present, there are no known biochemical imbalances in the brain of typical psychiatric patients—until they are given psychiatric drugs. It is speculative and even naive to assert that antidepressants such as Prozac correct underactive serotonergic neurotransmission (a serotonin biochemical imbalance) or that neuroleptics such as Risperdal or Seroquel correct overactive dopaminergic neurotransmission (a dopamine imbalance). The failure to demonstrate the existence of any brain abnormality in psychiatric patients, despite decades of intensive effort, suggests that these defects do not exist. 

Other molecular abnormalities are seen in schizophrenia (1) Serotonergic neurotransmission measured by the concentration of 5-HT and its metabolite 5-HlAA and the density of 5-HTl A or 5-HT2A receptors in post-mortem brain specimens (2) hormonal and behavioral responses to serotonergic drugs and (3) abnormalities of 5-HT and its metabolites in blood or CSF. 

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