Last month the Drug and Therapeutics Bulletin issued a release on a review of studies giving omega-3 fish oils for the treatment of depression quoting the review's conclusion saying 'there is no convincing basis for using these nutrients as a sole basis for this condition. There is limited evidence that 'omega 3s' might help relieve depression when given with antidepressant medication. However, this needs confirming before we can recommend the routine use of such supplements in patients with depression.'
Experts are calling this "a thinly veiled attempt to keep doctors prescribing anti-depressant drugs whatever happens", according to Dr James Braly, MD, an authority on science-based alternative, non-prescription drug therapies for depression, because the evidence of the studies in the review is quite different. Here's the essential finding:
(most studies measure depression on a scale called the Hamilton Rating Scale (HRS) - a higher score indicates worse depression)
Trial 1 - EPA 1g/2g/4g vs placebo - significant decrease in HRS (higher doses didn't work better)
Trial 2 - EPA 1g vs placebo - significant decrease in HRS
Trial 3 - EPA 1g/2g vs placebo in bipolar - both doses = significant decrease in HRS
Trial 4 - EPA 4g vs placebo in bipolar - not significant change
Trial 5 - DHA 2g vs placebo - not significant change
Trial 6 - EPA 0.44g, DHA 0.22g vs placebo - significant decrease in HRS
Trial 7 - EPA 0.6g, DHA 2.4g vs placebo - no significant decrease in HRS
Trial 8 - EPA 0.4g, EPA 0.2g vs placebo in children - significant decrease in depression
Trial 9 - EPA 6.2g, DHA 3.4g vs placebo in bipolar - significant increase in remission
So, if you add that up it's six studies show significant reduction in depression or remission from depression in bipolar; one DHA only study not significant; one 4g EPA trial in bipolar not significant; one EPA 0.6g/DHA 2.4g not significant. Let's assume that DHA is not effective in relieving depression (the same finding has occurred in ADHD type symptoms where DHA only studies have failed to work). That means six out of eight trials show significant reductions. The scale of reduction in depression on the EPA trial was an average 51% decrease in Hamilton Rating Score, compared to a 19% decrease in the placebo groups. Anti-depressant drug trials usually report something like a 15% reduction. In the child study, 7 out of 10 on fish oils had a 50% or greater reduction in depression rating, while none in the placebo group did. This suggests that EPA rich fish oil supplements may be twice as effective as anti-depressant drugs, generally halving depression ratings over an average of 12 weeks (study duration ranged from 4 weeks to 4 months).
With the exception of the child study, all trials gave fish oils to patients already on anti-depressants. (Its virtually impossible to get ethical approval to run a trial, stopping the anti-depressants. You'd be told that there's no evidence that fish oils can replace anti-depressants, and, until the evidence is there, you can't get ethical approval. Catch 22.)
So, here's an alternative conclusion. Six out of eight placebo-controlled trials, giving EPA in a dose range from 0.4g to 6.2g versus placebo, in addition to medication, show significant reduction, on average a halving of HRS score, in depression ratings or longer periods of remission in bipolar depression. There was a trend for doses above 1g to not be more effective than doses of 1g. One trial giving 0.6g failed to reach significance. However, a trial in children found 0.4g to be effective. The evidence is sufficient to recommend 1g of EPA to adult patients on anti-depressants, and possibly lower amounts to children. Trials are needed to test the effects of EPA on depressed patients who are not on anti-depressants, as well as children.
Drugs and Therapeutic Bulletin, February 2007. For details of the review, visit: http://www.dtb.org.uk/dtb/do