Anti-Depressants Change Brain Chemistry Immediately?

Check out the below article:

http://www.webmd.com/depression/news/20140918/one-dose-of-antidepressant-changes-brain-connections-study-says

More and more research is aimed at identifying the true effects of psychotropic drugs.  One of the most interesting insights from this article was the speed at which the brain begins to change when taking anti-depressants.  Patients have been told for years that medications take "4 to 6 weeks" to begin taking effect, but this research found evidence that one dose can create changes in the brain.