Have you had a hair transplant procedure done on yourself? If so have you ever tried or are you currently using propecia? I have been on propecia for about 2 months now and I find that my concentration/focus is severely lacking. I am currently going to grad school so you can see why this is a big problem. Whats your thoughts on the matter?
I have had two hair transplants on my crown and I take Propecia daily. I have not had problems like you are describing. Are you stressed? Try stopping the Propecia for a week and see if the concentration problem resolves. I would doubt that it would have this side effect, but there are many men who talk themselves into problems from the use of Propecia, a placebo type of effect.