As a pharmacist, taking prescribed drugs is very hazardous without proper care (even with the short term "benefits", I hope your doctor instructed you on the proper use of Ritalin and not some form of "Enhancer"). Taking Ritalin may have some psychological effects (aggressive behavior, bipolar symptoms, cardiac problems and others) because it is a central nervous stimulant that alters the biochemical composition. Just take if you really need it, if experience nausea, uncontrolled muscle twitching, palpitations, even some bouts of euphoria & hyperactivity call your doctor again.
That is why my country like to produce "herbal supplements", because many people believe after taking them, they will have a better memory, have a healthier heart, liver etc. but it is usually the person's will power---Sometimes people only need to believe on something. I saw a patient who underwent a minor surgery without any anesthesia (usually a anesthesiologist will give some form of pain management) but only requested to have her rosary and some church music. (If I'm going to surgery, drug me up with some Grade A morphine)