I would characterise OTC products for ADD useless. The underlying mechanism is under-activity in certain parts of the brain and stimulants are the only highly effective treatment. Though some people do respond to various antidepressants. The effectiveness of scam OTC products for ADD will all be less effective and likely more expensive than caffeine, pseudoephedrine and nicotine(which are all OTC).

I think all people should take fish oil for various reason but its not going to treat inattention either. I take 6 grams daily but I ran out yesturday. :)