Thanks for the replies. It has been roughly 4 weeks since we started using it. The doctor said to wait 4 - 6 weeks to observe any differences in behavior. So far, I have observed an improvement in his ability to focus on his work. Practice sheets (e.g., math) used to take 30 minutes to an hour to be completed. This week he spends about 10 - 15 minutes working on his practice sheets. The first time he yelled "done!!!" after completing his multiplication practice sheets, I could not believe it. +++ they were all correct. =)
If you google "Vayarin" you will find some comments by other parents that have experience using this supplement. I also read some articles from peer-reviewed journals that show significant differences between the experimental groups and placebo groups. You can find at least one peer reviewed article on Google Scholar.
My understanding is that this supplement is not available in all states, and it is a relatively new approach to treating ADHD. As far as the expense - my health insurance covers a portion of the cost, but not much. The doctor said the cheapest place to purchase Vayarin is at the Wal-mart pharmacy.
I hope this helps.