I read that athletes use Pseudoephrine to help increase concentration during training and wondered whether anyone had heard of it being used in the context of ADHD?

It's a mild stimulant (possibly related to amphetamines?) and a precursor to the street drug 'Crystal meths'. It's available over the counter as a Decongestant (i.e. Sudafed in the UK).

Please see the link below for a thread already in progress about this topic.

http://www.addforums.com/forums/showthread.php?t=2614&highlight=decongestants