I'm a 65 year old male. I have been taking Ritalin (generic) for three years. It has been helpful in terms of better concentration, etc. I could easily live without it but I do find it helpful. I have a tendency to abuse drugs, especially alcohol, but I'm alright with Ritalin.
Recently my doctor switched me to Adderall. It caused frequent urination and prostate fluid leakage in urine but the real problem is...kind of hard to describe. If it was 100 times worse it would maybe be like ants crawling under my skin. It is not really like that but that's the best I can do. Also, it doesn't help with concentration.