I was recently prescribed 20mg adderall ir for foggy thinking and lack of focus, but already had a significant tolerance to methamphetamine. Thus the adderall doesn't seem to have any effect on me at all. I'm unsure of what to do. Do I increase the dosage of adderall, or do I have to stay clean until my tolerance reduces? And how long would that take? Please advise..I honestly don't think I can be without either drug for very long without losing my mind. Thanks