"In Finland, the number of homeless people has fallen sharply. The reason: The country applies the "Housing First"

[Mosby]

18. In the US, homlessness is highly correlated with substance abuse.

Homelessness and substance use are often described as intricately related (Taylor et al., 2018). There is a widely accepted view that substance use has been regarded as both a cause and consequence of homelessness. In numerous studies, more than two-thirds of homeless individuals have reported that substance use had been a major cause of their homelessness (Khezri et al., 2020; Rew et al., 2001; Rosario et al., 2012; Santa Maria et al., 2018). Other studies have also stated that substance use had been a consequence of homelessness rather than a cause. Indeed, while these studies did have supporting evidence there is still a lack of suitable data that analyse substance use in the homeless population considering the different settings, locations and levels of homelessness (Prangnell et al., 2017; Tyler, 2013). Individuals experiencing homelessness are a difficult population to reach and for that reason many of the studies tend to be small-scall cross-sectional surveys with specific intentions (Aldridge, 2020).

A US based study found that alcohol prevalence ranged from 8.7 % to 84.8 % and substance use prevalence ranged from 4.5 % to 63.3 % among homeless population (Santa Maria et al., 2018). With drug overdose being the leading cause of death among the homeless, knowing the prevalence rate of substance use would better enable the understanding of the interactions between the overlapping issues (Laporte et al., 2018)

https://www.sciencedirect.com/science/article/pii/S2667118223000107