Abstract

Outline

It aims to support MHDAO in its review of the outcomes of the existing framework of care for this cohort across all relevant treatment settings in NSW and identify key areas for future action. As such, this report is intended for a diverse range of stakeholders as needed, including expert reference groups.

Executive summary

Comorbidity of mental illness and substance use disorders is a significant challenge facing the Australian health system. Despite a great deal of work in this area in the past 10 years, single disorder treatment models remain dominant. The silo structure of the healthcare system has historically treated clients in sequence of disorder (based on which is considered primary), or in parallel by different treatment providers. Recent evidence suggests that integration of treatment is ideal for optimal client outcomes and to avoid clients falling through the gaps. This Evidence Check sought to rapidly review the existing evidence for effective models of care for comorbid mental illness and illicit substance use. A number of limitations exist regarding the search strategy and the review itself, and are discussed in turn. Nevertheless, the review highlights the paucity of published work in this area.

Background

The top 10 causes of burden of disease in young Australians (15–24 years) are dominated by mental and substance use disorders. 4 Every year, alcohol and drugs conservatively cost the Australian community $23.5 billion. 5 Governments take the lead in managing this problem, with investments in health, community and law enforcement interventions across Australia estimated at $3.2 billion per annum. 6 Comorbidity (see Appendices 1 and 2) is common, with 25–50% of people with mental health disorders experiencing more than one disorder.

Effectiveness outcomes

The review generated a variety of differing models of care for comorbidity. These models vary on a range of components, which make comparison difficult. The majority use an integrated approach to treatment, although some indicate using a parallel delivery model. A significant difference between models occurred at a service structure level. A number of models were structured around a specialised comorbidity service (e.g. Burnaby Treatment Center for Mental Health and Addiction, Triple Care Farm), while others worked to incorporate alcohol and other drug (AOD) treatment into mental health services (Co-Exist NSW, Mental Health & Substance Use Service). These differing models have very different capacity to deal with comorbidity. Similarly, the inpatient/outpatient distinction inherent to treatment services will alter the nature of service provided and the resources available to each service.

Conclusion

Despite strong progress in recent years, much more work and commitment is required in the area of comorbid mental health and substance use problems, systemically, clinically and in the development of a robust evidence base. This is especially true among high-risk groups. Very little published work exists detailing service models of care for comorbidity. Furthermore, the models which do exist are rarely adequately evaluated. Further tailoring and integration of therapeutic components, along with the use of different, flexible modalities and a move towards considering multiple health risk behaviours, is essential to better reach and assist those in need. Ideally, services should adopt a ‘no wrong door’ approach to comorbidity, and service capacity should be built along these lines. Although it is difficult to recommend a ‘minimum critical set’ of program features due to the diversity of services, all services should acknowledge the high prevalence of co-occurring disorders and screen/assess, treat or refer and follow-up as appropriate.