The Tryptophan Depletion Technique in Psychiatric Research

Although tryptophan depletion (TD) is at this point familiar, if not exactly established in the study of depression, these are still early days for anxiety disorders. Now that conditions such as social anxiety disorder and generalised anxiety disorder have “matured” into an independent status, they have attracted more attention from researchers and the balance is in the process of being redressed. In summary, tryptophan depletion has established that the availability of serotonin is necessary for the action of SSRIs in depression. The picture in panic disorder appears to be similar, but the initial findings need replication, perhaps with the use of different chemical challenges. On the contrary, TD studies have been negative in OCD, perhaps because challenge tests have not been performed in this condition during TD. Studies are currently carried out in other anxiety disorders.