Comorbidity of substance use disorders and other mental health disorders: towards a common European approach

Background and objectives 

Comorbidity consists of the co-occurrence of a substance use disorder and one or more psychiatric disorders in the same individual. It is associated with increased emergency department admissions, psychiatric hospitalizations, a higher risk of relapse, and a greater likelihood of premature deaths, including suicides.3 Comorbidity is very difficult to detect and treat because mental and substance use disorders interact with each other in a continuous cycle. 

The impact of comorbidity on individuals, society, and public health is profound, demanding a multidisciplinary and comprehensive response to address the needs of affected individuals. Yet, there are significant gaps in health systems, which may be inadequately prepared to meet this challenge.

The EUDA[i] has developed important resources[ii],[iii],[iv],[v] on this topic including overviews of key issues related to comorbidity and existing interventions in Europe, analysis of epidemiological data, identification of screening tools, and outlines of key implications for policy and practice. The COVID-19 pandemic has intensified concerns about mental health, particularly among people who use drugs, and has drawn increased political attention at various institutional levels, including the European Commission7. This has led the EUDA to renew its efforts in addressing comorbidity, anticipating future challenges, identifying best practices, and informing the development evidence-based responses. 

Methods

In 2020 the EUDA set up an advisory board (AB) of high-level experts from different European countries to support the conceptualisation of main approaches to policy and practice to address comorbidity. The AB guides and oversees ongoing and future EUDA work in this field. Recent work includes a feasibility study for uniform data collection in Europe, an exploratory review of existing models of care for the treatment of comorbidity in Europe, and an updated overview of the most important aspects to consider when planning or delivering health and social responses to address comorbidity. This work was jointly developed by EUDA staff, members of the AB, and the REITOX network of national focal points. 

Outputs

Main outputs include the proposal for an entry in the Drug Treatment Demand Indicator database to collect uniform data on mental health in Europe, the mapping of existing models of care in several European countries, and a top-level digital resource on health and social responses to comorbidity. 

Looking ahead

Moving towards a common European approach, the EUDA Advisory Board on comorbidity continues to develop efforts to identify gaps that need to be addressed, prioritise areas for action, and guide existing EUDA work in this field. Among other projects, the AB is currently working on the identification of a European screening instrument for comorbidity, and planning a gap analysis exercise. 

 

[i] Previously EMCDDA (European Monitoring Centre for Drugs and Drug Addiction)

[ii] https://www.emcdda.europa.eu/publications/insights/comorbidity-substanc…

[iii] https://www.emcdda.europa.eu/publications/pods/comorbidity-substance-us…

[iv] https://www.emcdda.europa.eu/media-library/motion-graphic-drug-use-prob…

[v] https://www.emcdda.europa.eu/spotlights/comorbid-substance-use-and-ment…

7 Council conclusions on people having drug use disorders that co-occur with other mental health disorders https://data.consilium.europa.eu/doc/document/ST-16112-2023-INIT/en/pdf