Trouble concentrating. Ritalin - for adults?

I have trouble concentrating, especially at work, and a number of my friends (whom are nurses) have suggested ritalin... but through my searches on the medication, it seems it's not available for adults?  (only children)  

I was wondering if it's available for adults?
If Ritalin would help with concentration problems?  
What would the mg be for an adult dose?

Thanks.

[allmymarbles]

Why Ritalin, a medication that has side effects? I would suggest you try ginko biloba, a natural supplement that has been widely studied and has no side effects. I was once on a study with this herb for two years. There is absolutely no doubt as to its efficacy.

[little_hippie]

Im 25 and i was diagnosed with Adult Adhd just over 2 years ago, i was put on to Ritalin right from the start, altho it has so many side effects, i get on with it pretty ok. i find i can concentrate much better now and get on with alot of things i couldnt before, however, i get side effects from taking it, i lose my appeitie alot of the time so therefore i have very little control over my weight lose/gain, I also take Temazepam at night to try and help me sleep as that can sometimes be rather hard to wind down. this is also a side effect of Ritalin. i take a form of Ritalin called Concerta which is a 12 hour slow release.

sorry to go on, thought i would shed some light on some of the effects of Ritalin!