Old Concepts
The prevailing dogma concerning the pathophysiology of depressive disorders (major depression, dysthymia, bipolar disorder) is that of an altered neurotransmitter receptor and over the last several decades many studies have been conducted to find such an alteration. To date, there has been no demonstration of an alteration in the receptor binding site for any of the targeted neurotransmitters. Another problem with the altered neurotransmitter-receptor dogma is that although both tricyclic and selective neurotransmitter reuptake inhibitor drugs quickly enter brain and bind to their targeted sites, the clinical therapeutic effect does not occur for 4-6 weeks even though the onset of side effects is immediate.