antidepressant debate

January 13, 2010

There has been a debate for some time about the effectiveness of antidepressant medications, which are commonly used for anxiety and depression in routine psychiatric practice. A recent study published in the JAMA has reignited this debate, as it seems to indicate that there is little difference between antidepressants and placebo, for mild to moderate depression. In this large-scale randomised controlled trial patients with severe forms of depression benefited greatly from antidepressants when compared to placebo. Patients with mild to moderate depression seemed to respond both to antidepressants and to placebo.

This was discussed in depth at the Carlat Psychiatry Blog (written by a psychiatrist) It has been known for some time that the placebo response is powerful when it comes to depression and anxiety. This may indicate that these conditions naturally resolve with time, or perhaps it means that the power of belief has a very strong effect on mood – something we intuitively know to be true.

For psychiatrists, the question is whether or not we should prescribe antidepressants for the less serious forms of depression, and this is even more pertinent for GP’s who see the majority of such patients. It has been suggested that we should prescribe sugar pills for depression as the placebo response is so strong and this would benefit the patient without causing any side effects.

The majority of newer antidepressants have minimal side effects for the majority of patients. However there is a worrying trend towards increased suicidal thoughts in a small number of people, particularly adolescents. In practice antidepressant-induced suicide is virtually never seen, but this tends to show up in very large research trials.

I think this study also has implications for natural and alternative therapies, which are very popular but generally quite expensive for patients. We know that the placebo response is very strong, and so we can assume that the benefits of natural therapies are at least partly due to placebo response. Natural therapies are beneficial because they encourage healthy living and may assist mood in that way. It may be useful to bear in mind the placebo effect when considering the more costly therapies and may be advisable to seek a cheaper option!