The pathophysiology of schizophrenia and the major mood disorders is incompletely understood. Almost all psychotropic agents have essentially been discovered serendipitously, their mechanism of action researched and new molecules reverse-engineered based on the proposed mechanism of action. As a consequence, the clinically active mechanism of action of psychotropic agents remains opaque. Current understanding of the mechanism of action of antipsychotic agents focuses on monoamine neurotransmitters, and in particular dopamine, but includes a recognition of the role of serotonergic, noradrenergic and glutamatergic neurotransmission (1). However, there is emerging evidence that additional mechanisms of disease are operative in the major psychiatric disorders; these include oxidative and inflammatory pathways and the involvement of neurotrophins and neurogenesis (2). This is linked to our understanding that there is an active process of neuroprogression in these disorders (3). In this presentation, the role of these pathways will be briefly introduced. Evidence suggesting additional mechanisms of action of antipsychotics via oxidative and inflammatory pathways, as well as through the action of neurotrophins, will be presented. We know far more about the in vitro mechanism of action of these agents than we do about the role of these pathways in the genesis and remediation of psychiatric symptomatology, however, this new information will hopefully assist in providing a broader understanding of the pathophysiology of these disorders and the mechanism of action of antipsychotic agents. Incorporating a broader understanding of the mechanism of action of these agents may additionally assist in the process of new drug discovery.

References
1. Berk M, Dodd S, Kauer-Sant'Anna M, Mahli G, Bourin M, Norman T. "Dopamine Dysregulation Syndrome": Implications for a dopamine hypothesis of bipolar disorder. Acta Psychiatrica Scandinavica 2007; 116(Suppl.434): 41-49
2. Berk M, Ng F, Dean O, Dodd S, Bush AI. Glutathione: A novel treatment target in psychiatry. Trends in Pharmacological Sciences. 2008; 29(7): 346-351
3. Berk M. Neuroprogression: Pathways to progressive brain changes in bipolar disorder. Int J Neuropsychopharmacol May 2009; 12:4: 441-445.