Dr. Donovan's main research interest is to better understand how naturally occurring chemicals present in foods and supplements affect human health and disease. The biological effects of phytochemicals are dependent upon numerous processes, including absorption, transport, metabolism, and differential effects on cellular targets and signaling pathways. Recognition of specific metabolic pathways as well as the genetic and environmental factors that affect their regulation is essential to elucidate the mechanisms of action of phytochemicals in the context of specific diseases. Phytochemicals can also alter the disposition and hence activity of psychotropic and other medications through interactions with various drug metabolizing enzymes and membrane bound transport proteins. This is the basis for most food or herb drug interactions. Phytochemicals in foods may also be used clinically for weight loss and as adjuncts in the management of other mental illnesses. To date, little is known about the effects of foods and phytochemicals on psychotropic drug disposition or how diet and supplements may alter the course of mental illness. | 
