The problem with the studies if nutritional therapies? Often they have been poorly done, or investigated one nutrient at a time. A "paleolithic" focus requires cutting out grains, balancing the omega 3/6 ratio, and drastically reducing fructose and eliminating processed food. There are absolutely no randomized controlled trials for mental disorders with these criteria (unless you count the recent ADHD trial with the limited wheat and unlimited rice - which is why I post so much about the ketogenic diet trials, some omega 3 supplement trials, and the ADHD elimination diet trials - they are ALL I HAVE to truly hang my hat on. Everything else is just vague supporting evidence and a flair for spinning a tale, and don't think I don't know that.)
The letter in Science mentions the issue with mitochondrial dysfunction that often accompanies mental issues (see Brain Efficiency and Brain Efficiency, Pediatric Edition), and notes that nutritional problems may induce mitochondrial inefficiency.
And bless Science magazine - they discuss the problem of nutritional journalism, with the crappy headlines shadowing the misleading abstracts redoubling the worth of the Denise Mingers out there with every stupid headline:
"Medical journalism may be one important agent for spreading
information about legitimate research on nutrition and mental health,
especially in the face of the lack of profit-generated funding. This also
implies a special responsibility for medical journalists, since the dan-
ger of “pseudoscience” is close at hand."
Doctors cannot recommend therapies without evidence. And I shake my head at (for the most part) perfectly reasonable skeptic alternative health practitioners who eschew traditional prescriptions for traditional herbals which have no more evidence (and more than likely less regulation of the actual content of the herbal formulation) than any prescription product.
"Show me the evidence" should be the rallying call of the health-conscious consumer these days. Otherwise, I'll stick with eating nose-to-tail and seeking out seafood and going for the seasonal fruits, starchy vegetables, green leafy vegetables, and rendered fats and oils that my ancestors did.