Furthermore, studies clearly pointed out that social isolation can also be one of the main reasons for SUs to consume alcohol and use other substances. SUs with severe mental illness often experience social isolation due to various reasons such as stigma, relationship break down, lonely life, unemployment, poverty and homelessness (Lintzeris et al., 2016). For example, A 55 year old SU with diagnosis of depression stated that his wife’s death made him very depressed and he had to live a lonely life with all that grief. He stated that he initially alcohol to accompany him in his loneliness and eventually he became alcohol dependent to avoid loneliness. As SUs continue to use those substances, they develop tolerance for increased substance use
