Tuesday, September 16, 2008
Fish Oil as a treatment for ADHD?
Some physicians are now recommending fish oil in the form of omega-3 fatty acids or PUFAs (Poly-unsaturated fatty acids) as a therapy for ADHD children, adolescents and adults. This is partly in response to the persisting fears of parents about stimulant medications and partly on the basis of the always-hopeful findings in the literature, i.e. on the basis of inconclusive studies that "suggest further research is needed." As in most alternative therapies, some elements of basic neuroscience are cited as the rationale for the therapy, followed by "preliminary studies" which give hopeful signs (one might cynically say especially signs of future funding from government or pharmaceutical companies). In this case there are a number of animal studies which compare spontaneously hyperactive rats with their cool Sprague-Dawley cousins, who show signs of better cognition after dietary supplementation with PUFAs. Also, it appears that lack of these fatty acids are known to impede neural development in young babies. However, as for the scientific rationale, one respectable scientist says that, "...our current understanding of the importance of essential fatty acids (EFAs) and their metabolites to optimal brain function is based on an enormously complex set of interlinked biochemical, neurological, and laboratory observations. The applicability of these research findings to children with attention-deficit/hyperactivity disorder (ADHD) is unknown." (Betsy Busch, Polyunsaturated fatty acid supplementation for ADHD? Fishy, fascinating, and far from clear. J. Devel. & Behav. Pediatrics, Vol 28(2) Apr 2007, 139-144). What about clinical trials? One comprehensive recent review (E.H. Clayton, et al., Acta Neuropsychiatrica, Vol 19(2) Apr 2007, 92-103) found that 4 randomized controlled trials showed uncertain benefit for ADHD and no benefit for autism and bipolar disorder. A typical research story is illustrated from a controlled trial by A. Richardson and colleagues, who studied 41 children with ADHD and LD randomly assigned to highly unsaturated fatty acids (HUFAs) or placebo for 12 weeks. They found a mean improvement on 7 of 14 parent rating scales, "reaching significance levels on 3 of 14 scales." (Progress in Neuro-Psychopharm. & Biol. Psychiat. Vol 26, 2002, 233-39) Of course, they did not adjust for multiple tests, so technically the results are nil, but they call for further research.. By 2006, when reviewing the field, the same author concludes, "Omega-3 is not supported by current evidence as a primary treatment for ADHD or related conditions...." but still calls for further research. (A.J. Richardson, Omega-3 fatty acids in ADHD and related neurodevelopmental disorders. Int. Rev. Psychiat. Vol 18, April 2006, 155-172). Well, this is merely the research game as we have come to know it. I too have been enticed by small pilot studies that lead to larger grants (as in my flirtation with the Feingold diet studies, though there I took satisfaction in stopping a national trend sweeping the country which was diverting many parents from worthwhile treatments). One final research note on the dietary studies that also applies to drug trials involving parents and children. Many of these trials use apparently blind judgments by the physician which are in turn based upon reports by parents. But virtually all drugs create subjective awarenness by the patient that something is happening, and patients follow the demand characteristics of the experiment to give some response they think is expected, and parents as well as physicians become aware of side effects which allows a peek through the double blind. Note that in the previous study above the effects were found in parents but not by teachers (who are generally much more unaware of side effects and subjective bodily changes). When a trial shows parent reported changes but not teacher reported changes, one needs to be very suspicious about the signficance of any positive findings. All of those physicians out there who use the DSM-IV rating scale or global judgments as their outcome measures are likely to be subject to a positive bias about the drug being studied. After all, they get paid by the pharmaceutical companies and there is strong incentive to produce positive results and continued study. I have made this point many times at advisory committee meetings, but I have yet to find a single pharmaceutical company that pays attention to the suggestion of using blind raters who are separate from the physicians controlling the monitoring for side effects or adverse reactions. My conclusion from reviewing the literature on Fish Oil as therapy for ADHD is that it clearly is not proven. There are two therapies supported by research over a 40 year period: the combination of behavioral management (both in the classroom and at home); and stimulant drugs. But I make the following observation from my practice: it is usually quite useless to argue with a parent when they are predisposed against the use of drugs, no matter how noxious the child's behavior has become in their own lives. For those parents I make a therapeutic alliance by saying, sure, there are dietary therapies. First, make sure your child has a well-balanced diet, especially limiting their preference for high carb foods, and making sure there is plenty of protein at breakfast (I give them a pretty good story from our studies on this subject). I take a dietary history and recommend a 3-day diet diary, recording everything the child eats, and use it to steer the child and family away from obvious imbalances (there is good evidence that ad liibidem access to carbohydrates leads to an over use of them, especially in ADHD and Conduct-Disordered kids). I recommend limited access to sugar and sweets, but always balancing them with protein. For adolescents I am especially cautious about caffienated drinks. Eventually most parents return to the clinic after a few weeks saying, "Yes he (or she) is much better! But, you know, it's still a problem. What else can I do? I still don't want Ritalin." "Ahem, Madam, I agree and I can recommend a great medicine that is not Ritalin! (Well, it might be Metadate or Focalin or Adderall or Concerta or one of the other possibilities down the line when those don't work. But see my physician colleague, he (or she) knows all about it and can give you the latest medicine that works...") You get my drift. Since I do not myself prescribe, I rely on my savvy physician colleagues to know about the MTA study and the nuances of psychopharmacology that make for an effective treatment plan over the entire lifespan. (More on the MTA study in future postings.)