Antidepressants: better than placebo?

by Kim O’Donnell and John Ashmore

 

Antidepressants have become the “opiate of the masses” for the Western world – but are they actually effective? 

In his new book, The Emperors’ New Drugs, Professor Irving Kirsch argues that the benefits of antidepressants have been grossly exaggerated and that the pills may not be much more effective than placebos.

Kirsch has been investigating the efficacy of antidepressants for a number of years. In 1998, he and colleague Guy Sapirstein conducted a study at the University of Connecticut where they analysed the results of clinical trials on antidepressants.

The two researchers found that 75 per cent of the effectiveness of antidepressants could be ascribed to a placebo effect.

A commonly held theory about depression is that the condition is down to a “chemical imbalance” in the brain.   

The idea is that a deficiency of a certain chemical in the brain, such as serotonin, can lead to depression. Some antidepressants therefore work by promoting the production of these chemicals in the brain.

However, Kirsch regards the “chemical imbalance” theory as unsubstantiated.

“I think it’s a theory with little or any supportive evidence and some contradictory evidence – I would classify that as a myth at this point. One of the main problems with serotonin is that there are antidepressants that increase the amount of serotonin and others that decrease it, and they both have the same effect.”

This is not to say that Kirsch is dismissive of the achievements of medical science. “There are many wonderful drugs that are useful, the problem is that antidepressants aren’t one of them.”

What’s more, antidepressants can be actively harmful. As Kirsch points out: “There are numerous side effects, they can be quite serious. There are issues of withdrawal if someone is taken off suddenly, and especially for young people, an increased risk of suicide.”