One thing that might help answer this question (or not) is the fact that it’s completely insane how differently some depressed people will react to certain medications vs. others. I know people who swear by Effexor as a miracle drug for their depression and anxiety, whereas when I took it, I was unable to eat, unable to do such complex activities as walk down a hallway in a straight line, and generally felt like some sadistic mad scientist was screwing with my nervous system. I’m not sure if it really helped with my depression since I couldn’t really do anything other than sit around in the dark with my eyes closed and moan a lot.
If antidepressants have such a varied impact on people who ARE depressed, it would stand to reason they would have an equally varied impact on those who are not. So the answer to this question could vary wildly depending on the physiology of the patient.
My grandmother, who is not depressed but suffers a severe tissue disease, was prescribed an anti-depressant to help increase her pain tolerance. This seems to be one practical application of anti-depressants for non-depressed people, though she reported that it didn’t do any good.
Like I said, for me – Prozac is a party drug. It doesn’t need to build up, but in most people it does. My doctor asked me if I were joking when I told him that I had to take it at night because it made me goofy high – based on what his other patients had said, it shouldn’t have affected me the way it did, or as quickly as it did.
Depending on the level of functional analysis and the area of the brain in consideration, most neurotransmitters can be found to serve several functions. Serotonin may be a pain mediator, involved in rapid excitatory synaptic transmission, can sensitize an organism to cAMP, thus facilitating the response to a stimulus (e.g., facilitating learning, or at least Long Term Potentiation). These are just examples. There are seven types of serotonergic receptors, and just one can project to hundreds of cells spread diffusely throughout the brain. In response to the OP, the notion that a SSRI has no effect in a non-depressed person is silly. It has an effect, and whether or not you “feel” it is irrelevant. Depending on the makeup of the brain in question, I would expect a different reaction in every single person. Taking a drug with such a broad function is popular because the wide ranging side effects are either positive, less negative, or go unperceived, resulting in a net improvement.
IANN, but I do have Kandel, Schwartz and Jessell, 2000
