Many behavioral disorders are the result of chemicals in foods, personal care products, and household cleaners. If I were her I would not allow those toxic products and foods in my home - I don't even allow them in my home now and I don't have a child with those sort of problems.
I would also NOT allow my child to drink fluoridated water, take fluoride tablets, fluoridated dental care products, and I would avoid foods that are sources of fluoride... seriously. I wouldn't be at all surprised if many of our ills and diseases today are the direct result of fluoride, which we get in very large amounts because it is all over the place. It has never even been studied for efficacy or safety, I'm serious.
Learn more about the severe dangers of fluoride here (watch Christopr Bryson's video too)... http://www.fluoridealert.org/bryson.htm
Learn all the sources of where we get fluoride and how it's literally poisoning us and our kids...
http://www.fluoridealert.org/f-sources.htm
Plan to spend some time at that website, it's extremely educational. It will also change your thinking... the good things we've been conditioned to think are good.
The US government is even allowing fluoride to be used as a pesticide on potato plants and others.
I personally would not turn to conventional medicine for an issue like this because a drug will only be a bandaid covering the symptoms. I'm in Asheville, NC and there is an Integrative Medicine office where the doctor's are very keen on toxic things that cause weird health issues and common health issues. Their website is http://www.docbiddle.com
TN is not far from NC, if there isn't an Integrative practitioner near your friend I'd think it would be worth the trip to Asheville.
I'm not saying your friends sons problems are due to fluoride toxicity... what I do know is that it's extremely likely it's not helping the kid... or anyones kid or us for that matter.
If you're looking for effective, fluoride free, edible, dental care products contact me - I sell them.
Good luck!
E.