The antidepressant Prozac and related drugs are no better than placebo in treating all but the most severely depressed patients, according to a damaging assessment of the latest generation of antidepressants.
SSRIs, or selective serotonin reuptake inhibitors, were supposed to revolutionise care of depression – by treating symptoms without the side effects of older drugs, such as tricyclics.
But despite selling in vast quantities, a new meta-analysis of these drugs, from data presented to the US Food and Drug Administration (FDA), appears to suggest that for most patients they do not work. A previous study had indicated that the benefits of antidepressants might be exaggerated.
UK and US researchers led by Irving Kirsch of Hull University, UK, studied all clinical trials submitted to the FDA for the licensing of the four SSRIs: fluoxetine (Prozac), venlafaxine, nefazodone, and paroxetine (Seroxat or Paxil), for which full datasets were available.
They conclude that, “compared with placebo, the new-generation antidepressants do not produce clinically significant improvements in depression in patients who initially have moderate or even very severe depression”.
They did detect some benefits in the most severely depressed patients. But conclude that in this group the small effect is “due to decreased responsiveness to placebo, rather than increased responsiveness to medication”.