Serotonin-dopamine interactions: implications for the design of novel therapeutic agents for psychiatric disorders.

A close interplay exists between the serotonergic and dopaminergic neuronal systems both at the anatomical and functional level. It has long been known, at least in mammals, that the central serotonergic system modulates the activity of dopaminergic neurons in both the nigrostriatal pathway and ventral tegmental area. Since the discovery that reserpine and amphetamine induce symptoms in man that resemble those associated with depression and schizophrenia respectively, much attention has focussed on the development of drugs which affect the serotonergic and dopaminergic systems in psychiatric disorders. In this chapter, we will review some of the current research strategies targeting this neurotransmitter interaction that have driven compounds into clinical development in an attempt to provide more effective and safe medicines for such debilitating diseases.