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A study in Plos Medicine reports that newer generation anti-depressants are not effective in mild and moderate depression and show beneficial effect only in the most severely depressed. The new generation anti-depressants provide only modest benefits over the placebo and in some instances; the research data show no clinical significance of using antidepressants. The results published in the online medical journal Plos Medicine is from the meta-analysis of research data submitted to the FDA. The study also found that the effectiveness of the anti-depressants depends on the initial severity of the depression, with the drugs showing benefits above placebo only in the severely depressed. For the moderate and mild depression the newer generation anti-depressants failed to show any statistically acceptable clinical significance.

The drugs in question are the SSRIs – Selective Serotonin Reuptake Inhibitors which include fluoxetine, venlafaxine, nefazodone, and paroxetine. The SSRIs work by increasing the level of a neurotransmitter called serotonin in the extracellular space, by preventing its reuptake into the pre-synaptic cell. SSRIs are prescribed for depression, anxiety and some personality disorders. Fluoxetine is marketed under the trade name Prozac.

The assessment of the depression is generally done using the “Hamilton Rating Scale of Depression” (HRSD), which has a questionnaire having 17-21 questions, with each question carrying one point. The patients were assessed using the HRSD before and after the drug therapy. A different set of patients were assessed before and after placebo treatment. On average, the SSRIs improved the HRSD score of patients by 1.8 points more than the placebo, whereas NICE (National Institute for Health and Clinical Significance) has defined a significant clinical benefit for antidepressants, as a drug–placebo difference of HRSD score of 3 points or more.

The study has concluded the ‘that there is little reason to prescribe new-generation antidepressant medications to any but the most severely depressed patients unless alternative treatments have been ineffective’

Note that it may not apply to individual cases as averaging the data in a large study may obscure the benefits to the individual patients and you need to consult your doctor regarding any medications that you are taking. Refer to the link below where the original study is published for more details.

Reference

http://medicine.plosjournals.org/perlserv/pmed.0050045