Hi Melissa,
I am not sure I can tell you which medication is stronger than the others, but I can give you some information to read about each medication so that when you speak to your doctor, you will know what you need to ask. The three medications you listed are: Dexedrine (Dextroamphetamine), Ritalin(Methylphenidate) and Adderal (Amphetamine/Dextroamphetamine.) What I can tell you from reading these descriptions is that Adderall appears to be a combination of Dexedrine and Amphetamine. Which is why they might have switched you to dexedrine alone. This is something to discuss with you doctor.
Remember,
online sites are great resources for information so that you are able to ask
the important questions that will help you manage your healthcare, however they
can not take the place of your doctor's solid medical advice.
I hope this helps! Take care and stay in touch!Vicki M