Antidepressants: Myth or Miracle

I lost a close relative to suicide at the end of 2009. This was a very personal reminder of the importance of treating depression. Clinical depression can be a fatal.

I recently came down pretty hard on the lack of evidence for homeopathy treatments. To be fair we need to apply a similar sort of rigor to the question of antidepressant therapy. A recent article in Scientific American is entitled “Antidepressants: Do They 'Work' or Don't They?” highlights some important points.

In January the Journal of the American Medical Association (JAMA) published a paper which questioned the usefulness of antidepressants in patients with mild or moderate depression. Importantly, it did confirm that, “For patients with very severe depression, the benefit of medications over placebo is substantial.”

Lets me be clear about the issues at hand.

Unlike homeopathy treatments, anti-depressants must pass through a rigorous (and expensive) set of tests to demonstrate that they display ‘efficacy’. This means that clinical trials (or experiments) are performed where patients are assigned to receive either drug or a ‘sugar pill’ without either the doctor or the patient knowing which is being administered. After the results of treatment are recorded researchers go back and examine the effects produced by the drug relative to the sugar pill. Anti-depressants which make it to market must perform better than the sugar pill (the placebo).

The difference between treatment and sugar pill can be very small at times - but even a small difference can translate into a strong change for the patient since the effect of the placebo itself is very strong. Patients taking just a sugar pill improve about 75% as much as patients taking actual antidepressents (on average). This is why treatments like homeopathy, that haven’t passed rigorous testing, can appear to work – the patient simply believing it will work can have an extremely powerful effect.

To sell treatments that have no real medicinal value while treatments that do have actual medical value exist is unethical at best, and can distract patients from seeking legitimate treatment. Medicine has come a long way from the days where charlatans could make a living selling tonics to treat sickness with no proof that they work. We need to embrace this progress, not fight it.

So what the recent JAMA article concluded makes a lot of sense – the effect of antidepressants is strongest on people who have the most severe depression. Currently the best method we have for quantifying depression is Hamilton Rating Scale for Depression, but as we improve technologies, such as genetic testing and medical imaging, we may provide more accurate methods for both assessing depression and predicting which drug will work best for which patient. The application of personalized medicine will likely improve the treatment of complex syndromes such as depression.

So in the end do anti-depressants work? The answer is sometimes. Do we fully understand how they work or how to predict when they will work? No.

Much more work is needed, but we must remember that in cases of severe depression no treatment, or ineffective treatment can be fatal. We should be proud of the people who have the courage to tackle this problem with the scientific rigor that is required and discourage those who are looking to make money by selling false hopes and unproven therapies.