>Is there any scientific evidence for vitamin C & >B helping cognitive
I'm a clinical pharmacist with a personal interest
in noo/psychotropic drugs & nutrient supplements; the best info I can
indicates that the drugs & nutrients mentioned help prevent deficits in mental function (which is why I use them prophylactically) in otherwise healthy adults. Children receiving vitamin supplements have been shown to score higher on IQ tests, but IMO this reflects a simple correction of a malnutrition-induced deficit.
As to the difficulty in separating out the placebo effect with
nootropics, this is all too true; I haven't found any well-controlled
studies on healthy people & nootropics outside of the ones on caffeine &
amphetamines. There is some evidence that antianxiety agents such as
dose benzodiazepines & propranolol, a centrally acting adrenergic receptor blocker, improve test scores, but again this is not well studied & is most likely a reduction in noise, not a boost to the signal. Potentially useful in many situations,
I must admit.
In short, I must conclude there are as yet no clinically proven nootropics out there yet. If it works for you, though, & the cost-benefit estimates work out, results are what matter; your life, your choice, as it should be.