previous page  | table of contents |  next page

5.0 Key Assumptions

  • Dual diagnosis is a complex condition that often requires a multi-faceted service response from both the health and social services sectors. Effective cross-sector collaboration at all levels is essential to the provision of appropriate services.
  • Services for adults (age 18 and older) with a dual diagnosis are a responsibility shared by both ministries. While some responsibilities such as policy direction and planning are shared by both ministries, other responsibilities are distinct. Community-based mental health services and supports include: counselling and treatment, 24-hour crisis response including short-term crisis residential beds, Assertive Community Treatment Teams (ACTTs) and consumer/survivor/ family initiatives. Developmental services include: residential, community participation and respite supports, case management, and specialized community supports (refer to appendices 1 and 2 for lists of services).
  • System planning for transitional age youth (ages 16 and 17) with a dual diagnosis is a responsibility shared by both ministries to work with the Ministry of Children and Youth Services (MCYS) which has responsibility for developmental and mental health services for children and youth under age 18. Local system planning will also occur to facilitate the transition of youth to adult services.
  • Individuals should have access to a continuum of care that provides the most appropriate and least intrusive service possible, based on assessment of need. For some, this may mean support through general health care services such as primary care providers and general hospital services. For others with more complex needs, integrated cross-sector responses may be required. A segment of the population may require access to specialized services that integrate the expertise and knowledge of both the mental health and developmental services sectors.
  • Mental health and developmental services funded by the Ministry of Health and Long-Term Care and the Ministry of Community and Social Services are responsible for continuing to work collaboratively within and across sectors so that individuals who have a developmental disability and mental health needs receive the appropriate levels of service to respond to those needs and so that effective case resolution mechanisms are in place in communities.
  • It is an expectation of the Ministry of Health and Long-Term Care and the Ministry of Community and Social Services that this joint Guideline will be implemented across the province by the responsible parties.

6.0 Demographic/Prevalence Rates for Dual Diagnosis

While the Statistics Canada Participation and Activity Limitation Survey (PALS) sets the prevalence rate of people who have a developmental disability in Ontario as 0.7 per cent other sources cite the rate as more appropriately expressed as being between 1 to 3 per cent of the population.2 Using the prevalence rate of 1 per cent and the Ministry of Finance 2005 Ontario population figure of 12,540,000 there are 125,400 persons with a developmental disability estimated to reside in Ontario.

The National Association for the Dually Diagnosed (NADD) estimates that 30 per cent of the population with a developmental disability also has a mental health disorder. Other sources have suggested the prevalence of dual diagnosis may range as high as 38 per cent. Using the NADD figure of 30 per cent, it is estimated that there are approximately 37,620 individuals with a dual diagnosis in Ontario.