A heavy load of symbolism surrounds psychoactive substance use, for reasons which are discussed. Psychoactive substances can be prestige commodities, but one or another aspect of their use seems to attract near--universal stigma and marginalization. Processes of stigmatization include intimate process of social control among family and friends; decisions by social and health agencies; and governmental policy decisions. What is negatively moralized commonly includes incurring health, casualty or social problems, derogated even by other heavy users; intoxication itself; addiction or dependence, and the loss of control such terms describe; and in some circumstances use per se. Two independent literatures on stigma operate on different premises: studies oriented to mental illness and disability consider the negative effects of stigma on the stigmatized, and how stigma may be neutralized, while studies of crime generally view stigma more benignly, as a form of social control. The alcohol and drug literature overlap both topical areas, and includes examples of both orientations. Whole poverty and heavy substance use are not necessary related, poverty often increases the harm for a given level of use. Marginalization and stigma commonly add to this effect. Those in treatment for alcohol or drug problems are frequently and disproportionately marginalized. Studies of social inequality and substance use problems need to pay attention also to processes of stigmatization and marginalization and their effect on adverse outcomes.