Substance use by homeless clinic attenders in Sydney

Objective: Describe patterns of substance use and comorbid conditions among clinic attenders in homeless shelters in Sydney.
Method: Retrospective cohort study of 2498 people who attended a psychiatric clinic at one of three homeless hostels between February 2008 and May 2020. Multivariable logistic regression was used to identify factors associated with self-reported substance use, psychiatric diagnosis and measures of social function.
Results: A total of 2041 of the 2498 (81.7%) reported the harmful use of at least one substance, with alcohol (61.8%), cannabis (50.9%) and stimulant drugs (34.9%) the three most common. Those reporting the regular use of two or more substances (1466, 58.7%) were more likely to have a history of early life and adult trauma, a diagnosis of personality disorder, a criminal conviction, receive the Disability Support Pension, be chronically homeless and sleep in the open.
Conclusions: The study found a high rate of polysubstance use among homeless clinic attenders in Sydney, and an increase in the prevalence of substance use compared to previous studies. Substance use is both a cause and a consequence of homelessness, and services to address substance use have to be part of any program to reduce homelessness and sleeping in the open.