Generally, 60 mg total per day is the maximum recommended dose of Adderall for adults. If you and your doctor agree to go up to this dose yet your symptoms are not well controlled, then you likely should be on a different medication (either on its own to replace adderall or in addition to it).
Please see the following link for additional information.
http://adhd.emedtv.com/adderall/adderall-dosage.html
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Board Certification by American Board of Psychiatry and Neurology