New generation antipsychotics in the treatment of schizophrenia: dopamine stabilizing agents and aripiprazole

Schizophrenia is a major mental disorder starting mostly during adolescence and cause significant disability. Positive and negative symptoms and cognitive dysfunctions are main domains of schizophrenia. Dopaminergic hyperactivation in mesolimbic regions is related to positive symptoms whereas hypodopaminergic activity in prefrontal regions is related to negative symptoms and cognitive impairments. Therefore an ideal antipsychotic must have the ability to decrease hyperdopaminergic activity in mesolimbic areas and increase dopaminergic hypoactivation in prefrontal lobes. Recently developed Serotonin Dopamine Antagonists (SDA) have this ability. Dopamine Stabilizing Agents (DSA) demonstrate similar characteristics resembling to this hypothesis. DSA functions according to to the levels of dopamine. SDA decreases dopamine if high, and increases it if low ("Dual Effect"). Aripiprazole, a DSA that was approved first by regulatory agencies, improves positive and negative symptoms clinically in patients with schizophrenia and is safe. It also causes less Extrapyramidal Side Effects, no increase in prolactin levels, serum glucose, cholesterol and triglyceride levels, weight, and blood pressure that are all related to metabolic syndrome.