I have just plain ol' ADD and I found that some pu'erh teas are strong enough to replace my meds. It's a great situation, tea is cheaper, healthier, and doesn't have the nasty crash that prescription amphetamines do, though if you brew it too strong, it's just like a mild OD of my former meds. It also gives me a great excuse to buy more tea. "It's for medicinal use, really!"
My medicinal tea of choice: 2005 6FTM Yiwu ltd. It used to be cheap, tastes good (extremely floral aromatics), and kicks like a mule.
A link to a review for the 2004 version: