Mixing these two drugs is just plain dangerous, and could end up being quite unpleasant, too. Both of these stimulants work in DIFFERENT ways. The Adderall (mixed amphetamine salts) works by releasing neurotransmitters into the synapse area, and Ritalin (methylphenidate) works by preventing the neurotransmitters that naturally end up in the synapse area from leaving. The main neurotransmitters involved are dopamine, norepinephrine, and serotonin - all of which are cause of these two drugs' effects. In mixing them, the synapse area would be flooded with those neurotransmitters (released more than they are naturally released due to the Adderall, and kept there more than they usually are with the Ritalin). The result could be an overdose, even if the doses are "low" to you by themselves. If you want a good high, just up the dose of one or the other a bit (not to an unsafe point), and enjoy that one or the other, whichever you choose. Please, don't mix. Really unsafe. Amphetamines + methylphenidates is just a BAD idea.