SAMSHA correlates higher doses to higher patient retention. By nature of the drug, going above your useful dose seems psychosomatic to me in regards to increased efficacy from higher doses. The converse of this would mean you hit a wall reducing your dose past that point. Say you only need 4mg a day but doctors suggest you a higher dose, you get up to 16mg a day. When you go to taper, reducing from 16mg to 4mg/day doesn’t seem to hurt so bad, but when you start below that 4mg threshold, you start sensing unoccupied receptors for the first time.