Hi. I've noticed from your profile that you're 40ish like me, and I commend you for being in school... because I couldn't do it anymore. I was in the advanced classes in high school, did well post-secondary, but my concentration and recall has gone down the tubes.

I've become really scatterbrained at work - it's unreal how many tasks I have half-done because I get distracted and forget about the other five things I have on the go, instead of finishing one task then moving on. I've been able to manage by having routines, making lists, and writing down every phone message... but I'd be lying if I denied having chemical help. I'll have a sugar-free Red Bull here and there, and I've even "abused" sinus pills because they make me sharp as a tack. (No wonder Ritalin is effective...)

I've never noticed any improvement with a higher-carb diet. Carbs knock me out, if anything. YMMV, of course. I think if you're noticing a difference, it's an adrenaline rush, maybe?

I think the best you can do is try to make sure the rest of your lifestyle is supportive of your studies. Are you getting enough sleep? Taking breaks? Clearing your head by going for a walk? When I answer "no" to these questions, that's when I head for the stimulants. I work shift and the sleep thing is huge for me.

Best of luck to you.