Anxiety disorders have long been a research subject for scientists in different areas of inquiry, and the particular role of serotonin -- the neurotransmitter which has probably most captured the imagination of laymen and academics alike -- is as elusive as the clinical aspects of serotonergic medications. Why are drugs acting at certain serotonin receptors efficacious against generalized anxiety disorder, but not panic disorder? Why is the inverse true for monoamine oxidase inhibitors? These clinically relevant issues are clarified by the neurochemical, anatomical and physiological...