The question of potential addiction to self-induced states that activate the dopamine (and/or other neurochemical) reward system(s) is important. From a more philosophical angle, should we welcome beneficial addictions that, if cultivated, might significantly improve individual and group quality of life? Isn't this related to our high regard for replacing detrimental with positive habits? Habit formation and maintenance also depends on activation of neural reward systems (see Nir Eyal's book, Hooked).