The relationship between substance use and homelessness is complex. While rates of substance use are disproportionately high among the homeless population, homelessness cannot be explained by substance use alone. The use of substances alone does not necessarily signal addiction, nor a harmful or problematic lifestyle. In addition, many people who are addicted to substances never become homeless, but an individual that is experiencing housing instability, often due to low income, has an increased risk of losing their housing if they use substances. Once on the streets, an individual with substance use issues has little chance of getting housing as they face insurmountable barriers to obtaining health care, including substance use treatment services and recovery supports.
The term "substance use" refers to all types of drug and alcohol use. It is used in place of the traditional label of "drug abuse" which perpetuates social stigma and judgment and can marginalize and alienate people from the supports they need. The term "use" signals a push to reduce the harms for all users - from the person who uses drugs or alcohol occasionally, to someone who has a serious addiction. The term "substance", rather than drugs, better reflects the full range of psychoactive substances including alcohol, cigarettes, illegal drugs, prescription drugs, solvents, and inhalants that are habit-forming.
The potential harms associated with the use of substances are many. This includes pharmacological effects of the substance itself that may impair a person’s ability to safely and competently make decisions and carry out tasks that they engage in. Problematic substance use may lead to deteriorating health; accidental death; and increased chances of risky sexual behaviours. Other harms that may result from problematic use of substances include: the inability to work or stay in school, ruptured relations with family, friends and community members, and problems with the law.
Responses to substance use are varied. They include: prevention (which may emphasize abstinence, at one extreme, or harm reduction), treatment (for those whose substance use is considered problematic), harm reduction (programs that seek to reduce the risk of substance use) and enforcement. The latter point is important. In Canada, as elsewhere, the use of substances is highly politicized, meaning that some potentially harmful substances are legal (cigarettes and alcohol, prescription drugs), while others are not. As a result, a potential "harm" of substance use is getting arrested.
People that live on the streets and engage in substance use have many risks, one of which is difficulty obtaining and maintaining employment and housing. The frequency of such problems suggests the potential viability of harm reduction programs that provide a safe environment for stabilization to clients who are unable to maintain abstinence. As well, stable supportive housing is needed to give people an environment in which they are better able to deal with their substance use problems.
Transitional housing is frequently recognized as an approach to addressing substance use problems, and is often provided through emergency shelters and supportive recovery facilities. Often, though these housing options require abstinence in order to accept clients. The result is that many people fail to qualify, and remain on the streets or in environments that are not conducive to addressing their substance use problems. And even if they do complete treatment, because of a lack of supported housing options, once they are discharged from hospital or treatment center, many people with substance use issues have no place to live, a situation which puts their recovery in jeopardy.