Neuroreceptor imaging has a major role in aiding how to administer a clinically effective drug dose that minimizes dose-dependent side effects. Considerable lines of evidence converge to confirm that alterations in the density, distribution, and function of dopamine D2/D3 receptors in the brain play a role in the pathophysiology of schizophrenia. Positron emission tomography (PET)/single-photon emission computed tomography (SPECT) receptor occupancy allows determination of the likely optimal dose of dopamine D2 receptor blocking drugs to produce a therapeutic effect with minimal adverse effects. Pharmacological challenges are one of the most promising areas in in-vivo neuronal receptor imaging to alter neurotransmitters levels. Serotonin is the second major neurotransmitter system studied in schizophrenia. Glutamate, the excitatory neurotransmitter, likely has multiple roles in the pathogenesis and pathology of schizophrenia. A novel approach to the treatment of schizophrenia is the use of anti-psychotic medication.