Drug and alcohol services - co-occurring substance use and mental health concerns: literature and evidence review

Key Findings

This report provides a rapid review of the literature on co-occurring substance use and mental health concerns and the integration of mental health and substance use services in Scotland. In doing so, it outlines evidence on the estimated prevalence of co-occurring substance use and mental health concerns, the barriers people experience in accessing services and support, and policy development to date. Finally, it identifies key recommendations highlighted in the literature with regard to improving services for people with co-occurring substance use and mental health concerns and highlights a number of key areas for further research.

Prevalence

• There is a lack of systematically gathered data on the exact prevalence of co-occurring substance use and mental health concerns in Scotland.
• Overall, evidence shows that co-occurring substance use and mental health concerns are a common issue. There are indications that in Scotland adults who use substances report lower mental wellbeing scores than adults who do not and it is estimated that problem substance use was a factor in between 48% and 56% of suicides between 2008 and 2018. Evidence from the UK Government shows that in England in 2021, nearly two-thirds (63%) of adults starting treatment for substance use had a mental health treatment need.
• People experiencing homelessness are at higher risk of experiencing co-occurring substance use and mental health concerns than the general population.

Barriers to accessing treatment

• Lack of integrated services - Lack of integration between mental health and substance use services is identified as a key barrier to accessing adequate treatment and support. It is also considered a barrier to effective service delivery as the lack of a consistent, joined-up approach results in failures to diagnose or recognise the needs of people with co-occurring substance use and mental health concerns, as well as having negative effects on treatment outcomes.
• Requirement to abstain from drug use prior to accessing mental health support - Several sources highlight that mental health services may require individuals to cease using substances prior to receiving treatment for their mental health. This is a particular barrier where substance use may be a form of self-medicating to manage mental health concerns, as it removes a coping mechanism prior to any other form of support being in place.
• Quality of care – The literature indicates that quality of care impacts both service users' access to services and their treatment outcomes. The variation in the quality of care received was attributed to a number of issues, including staff attitudes; interpersonal tension or conflict between service users and staff; a lack or insufficient continuity of care; and fragmented service responses. Evidence also showed that experiences of racism or stereotyping were barriers for minority ethnic groups, as was lack of inclusivity for people in the LGBTI community.
• Stigma - There is evidence that stigma creates barriers both to accessing services (particularly where stigma is perceived to come from service providers) and to quality of care. It can also reinforce trauma and have negative effects on mental health. The literature particularly highlights the effect of self-stigmatising views for older substance users and people from minority ethnic communities.
• Homelessness – Research further outlines the additional barriers faced by people experiencing or at risk of homelessness. Barriers to access reported by those with lived experience of homelessness included: increased stigma, fear of being turned away when seeking support from services, varied interactions with frontline staff, limited availability of services and challenges associated with their physical location.

Recommended interventions

• Person-centred and trauma-informed approaches – A significant body of literature continued to emphasise the importance of holistic, non-judgemental person-centred and trauma-informed approaches, in line with existing policy approaches.
• Staff training – Training was identified as a factor impacting staff attitudes and inter-agency and interdisciplinary working, as well as being central to providing person-centred and trauma-informed care.
• Service integration and networks – The role of formal and informal mechanisms of the integration of mental health and substance use services, as well as wider physical health, housing and other social services was emphasised across academic and policy literature as being central to delivering joined-up support.
• Support for people experiencing homeless – Evidence reviewed a range of approaches for supporting people with co-occurring substance use and mental health concerns. Harm reduction approaches and case management were shown to have positive substance use and mental health outcomes.
• Youth substance use – Evidence specifically focusing on young people highlighted the need for early diagnosis and the integration of access to a range of services in addition to support for substance use and mental health. These included housing support, mentoring programmes, financial support and social services.