Taking Prozac for depression is mostly a waste of time, say scientists

Published on Monday 25 February 2008 21:21

NEW-GENERATION antidepressants, such as Prozac and Seroxat, are largely a waste of time, research suggests.

A review of clinical trials found that they worked no better than a dummy pill for mildly depressed patients and for most people suffering severe depression.

Even trials suggesting that the drugs helped severely depressed people provided no evidence of clear clinical benefit, the researchers said.

Dr Tim Kendall, the deputy director of the Royal College of Psychiatrists' research unit, said the findings were "fantastically important".

The researchers said: "Drug-placebo differences in antidepressant efficacy increase as a function of baseline severity, but are relatively small, even for severely depressed patients.

"The relationship between initial severity and antidepressant efficacy is attributable to decreased responsiveness to placebo among very severely depressed patients, rather than to increased responsiveness to medication."

The researchers said their study was one of the most thorough investigations into the efficacy of new-generation antidepressants, known as selective serotonin reuptake inhibitors .

The research looked at trials into drugs including antidepressants regularly prescribed in the UK, such as fluoxetine (Prozac), venlafaxine (Efexor) and paroxetine (Seroxat).

The researchers concluded: "Using complete datasets (including unpublished data) and a substantially larger dataset of this type than has been previously reported, we find that the overall effect of new-generation antidepressant medications is below recommended criteria for clinical significance."

The paper, Initial Severity and Antidepressant Benefits: A Meta-Analysis of Data Submitted to the FDA, was published in the journal PLoS (Public Library of Science) Medicine.

Prof Kirsch said: "The difference in improvement between patients taking placebos and patients taking antidepressants is not very great.

"This means that depressed people can improve without chemical treatments.

"Given these results, there seems little reason to prescribe antidepressant medication to any but the most severely depressed patients, unless alternative treatments have failed to provide a benefit."

He said: "This study raises serious issues that need to be addressed surrounding drug licensing and how drug trial data is reported."

Dr Kendall echoed the view that the study was important because it looked at both unpublished and published trial data.

WHAT THE DATA SHOWED

EXPERTS analysed 47 clinical trials using data released in the US under freedom of information rules.

They looked at four common antidepressants and the clinical trials submitted to gain licensing approval. They found little evidence of benefit when analysing both unpublished and published data from the drug companies.

Seemingly good results for very severely depressed patients came from a decrease in the patient's response to the placebo, rather than any notable increase in their response to the drugs.