Injection drug use and crack cocaine use are major factors in the transmission of HIV and have been associated with non-adherence to ART. Several types of interventions have been effective in promoting short-term ART adherence in these populations. Counseling strategies and reminders (e.g., beepers, calendars, etc.) have each had modest effects. Still more successful approaches have included directly administered antiretroviral therapy (DAART, in which patients are observed by care providers as they take their medication), medication assisted therapy (e.g., methadone maintenance), and contingency management (monetary incentives for maintaining adherence to HIV medications). However, a core problem with all ART adherence interventions is that their effects do not appear to last after the interventions are discontinued. In a recent review of ART adherence interventions for drug users, researchers expressed concern over the "virtual lack of interventions with sustained post-intervention adherence and virologic benefits." The common finding of post-intervention dissipation of effects suggests that ART adherence interventions may need to be implemented as long-term or even permanent adjuncts to ART for drug users.