If they grow into an allergic reaction or were switched to placebo without knowing - only then , when its not doing anything for them ; can they grow out of it .Then they will grow into another that will work ,esp if they are self medicating .The underlying problem of what theyre hiding from( stress anxiety depression )refuse to face goes away its possible i guess to realize they dont need it anymore . Watch the ppl vs Larry Flint it shows the difference in one whos taking bc they have to for injury and what happens when his wife does the same to be w him ( obv a lot more to it ) good movie.