Action of Antipsychotics

The discovery of chlorpromazine and similar drugs, called as antipsychotics, shown to be effective in treatment of schizophrenia heralded a new era in modern psychopharmacology more than half century ago. Because the initial discovery was serendipitous, it took more than a decade to understand the mechanism of action of these drugs. However, despite major breakthroughs and important discoveries, their mechanism of action remains elusive and many issues are still unresolved. While the field embraced the notion of dopamine receptor blockade as the mechanism initially, later developments have challenged the emphasis on D 2 blockade. Both action at neurotransmitter receptors and actions through intracellular pathways are hypothesized. Nonetheless, evidence demonstrates that at least some degree of D 2 receptor blockade is necessary for antipsychotic activity of currently available medications. In this article, we will review the action of antipsychotics and different theories to explain their mechanism of action.