Advances in basic neurobiology and neuropharmacology over the past two decades have shown that specific receptor molecules in the brain are the major targets of neurotransmitters and many psychopharmacological agents. New research disciplines dealing with the physiology and pharmacology of brain neuroreceptors have emerged. Although these developments have been of great theoretical and heuristic value to clinical psychiatrists, methodological limitations hitherto precluded the application of this new knowledge in the clinical field to the benefit of individual patients. Recent developments of brain imaging techniques such as computed tomography (CT), nuclear magnetic resonance (NMR), and positron-emission tomography (PET) undoubtedly have been instrumental in narrowing the gap between experimental and clinical research in neurobiology.1-3 Computed tomography and NMR have already proved their value by demonstrating alterations of brain structure in neurodegenerative disorders and schizophrenia.
Positron-emission tomography may have an even greater potential, since this technique makes it possible to examine biochemical