You have been taking a very responsible dosage. In fact, if you truly have ADD (low pf DA levels), then taking 20-25mg (no more) of amphetamine orally spread out over a day is a perfect dosage, one that doesn't damage DA receptors through amphetamine-induced dopamine oxidation, which means very minimal withdrawals compared to the people taking more than 40mg/day for their ADD.
As with all medications, it is always best to taper. This will reduce or eliminate mental withdrawal symptoms, such as an intense ADD rebound, fatigue, and depression. I would taper from 20mg taken over the course of a day to:
-1.) 10mg XR am, 5mg IR pm
-2.) 10mg XR am, 2.5mg IR pm
-3.) 10mg XR am
-4.) 5mg IR am, 2.5mg IR am
-5.) 2.5mg IR am, 2.5mg IR am
-6.) 2.5mg IR once a day
I would hold at each step for a week, and stay at step 5 and 6 for 2-3 weeks each. Amphetamines seriously change your DA receptors' neurochemistry, which is alright if you properly taper it like any other psychiatric medication.
I am always a proponent of very slow tapers for GABAergics, opiates, antidepressants, and amphetamines, it prevents relapse rate due to proper management of discontinuation symptoms. If a taper is done slow and organized enough, you literally feel barely any withdrawal symptoms. With tapers, slow and steady wins the race! Good luck
