Ironically and cruelly, eventually even the drug loses its ability to reward, but the compromised brain leads addicted people to pursue it, anyway; the memory of the drug has become more powerful than...Ironically and cruelly, eventually even the drug loses its ability to reward, but the compromised brain leads addicted people to pursue it, anyway; the memory of the drug has become more powerful than the drug itself. Over time, the brain adjusts to excess dopamine activity, which ultimately results in the effect known as tolerance, leading the user to take more of the drug in order to achieve the same high.