What will help me concentrate and be a little more attentive in cles?

I am in my first year in college, and am struggling a little bit to pay complete attention in cl. I don't have an extreme case of add, so I don't want to take aderol or anything in that nature. I need something to simply boost my mind mentality, and to help me focus. I've heard dlpa might work or dhea. Please let me know if you have any information on these products or if you could give me a recommendation.