Wednesday, 04 April 2012
A recent TIME article discusses a study in which researches, led by assistant professor of psychiatry at UCLA Aimee Hunter, found that a person’s pervious experience taking antidepressants can influence future responses to medications and placebo treatments.
The study, published in European Neuropsychopharmacology, reports that participants in a placebo group who had a prior history of taking antidepressants showed brain changes that were indistinguishable from those participants who were given medication. This indicates that, for the participants who had previous experience taking antidepressants, the act of taking a pill (the placebo) elicited the same response seen in the people who actually received medication.
Depending on past experience, this placebo effect can be either positive or negative. Hunter explains: “With regard to antidepressants, people who have previously taken the drugs and felt better might have a similar physiological response to the cue of being given a pill that is said to be an antidepressant. In contrast, those who took a pill and got worse or did not improve might come to have a negatively conditioned response. This could explain at least some of why depression becomes resistant to treatment.”
Another potential problem of this placebo effect is that even when new antidepressants enter the market, one could be psychologically conditioned not to be able to benefit.
Hunter acknowledges that there may be other possible explanations for this perceived placebo effect and further research is needed.