A<unk>  is the<unk>  regarding the control and regulation of psychoactive substances (commonly referred to as<unk> s), particularly those that are addictive or cause physical and mental dependence. While<unk> es are generally implemented by governments, entities at all levels (from international organisations, national or local government, administrations, or private places) may have specific<unk> es related to<unk> s.<unk> es are usually aimed at combatting<unk>  addiction or dependence addressing both the demand and supply of<unk> s, as well as mitigating the harms of<unk>  use, and providing medical assistance and treatment. Demand reduction measures include voluntary treatment, rehabilitation, substitution therapy, overdose management, alternatives to incarceration for<unk>  related minor offenses, medical prescription of<unk> s, awareness campaigns, community social services, and support for families. Supply side reduction involves measures such as enacting foreign<unk>  aimed at eradicating the international cultivation of plants used to make<unk> s and interception of<unk>  trafficking, fines for<unk>  offenses, incarceration for persons convicted for<unk>  offenses.<unk> es that help mitigate the dangers of<unk>  use include needle syringe programs,<unk>  substitution programs, and free facilities for testing a<unk> 's purity. The concept of "drugs" –a substance subject to control– varies from jurisdiction to jurisdiction. For example, heroin is regulated almost everywhere; substances such as khat, codeine, or alcohol are regulated in some places, but not others. Most jurisdictions also regulate prescription<unk> s, medicinal<unk> s not considered dangerous but that can only be supplied to holders of a medical prescription, and sometimes<unk> s available without prescription but only from an approved supplier such as a pharmacy, but this is not usually described as a<unk> ". There are however some international standards as to which substances are under certain controls, in particular via the three international<unk>  control conventions.
Drug policy
Community health
Doctor–patient relationship
Personal medicine
International health
Cost of Living 
Organ care system
Regulatory science