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Dual/Concurrent/Co-morbid Diagnoses

“Dual Diagnosis” has been used to refer to the occurrence of both a mental illness and a developmental disability (see the reverse for a definition) in the same person. Some examples of developmental challenges are: intellectual disability, (also known as mental retardation); learning disability; Downs Syndrome; Prader-Willi Syndrome and Autism Spectrum Disorder.

Concurrent diagnosis refers to the presence of an addiction as well as a mental illness. However, in the United States, they use the term dual diagnosis to refer to this condition. Co-morbid, or co-occurring disorders means they are commonly found together in the same person, i.e. AD/HD + Obsessive-Compulsive Disorder).

Often, a dual diagnosis is not given right away. Usually, either the developmental challenge or the mental health issue is diagnosed first and the other is recognized later on.

For our reference and for many other professionals in Waterloo Region, dual diagnosis is referring to a developmental disability PLUS a diagnosis of a mental health disorder.

If a diagnosis of a developmental disability has been made, regardless of other diagnoses, the family/guardian can access services through Developmental Services Resource Centre (DSRC). (click on the link below).

Adults requiring developmental services will need to contact Developmental Services Ontario (DSO) to determine eligibility (click on the link below).

If a diagnosis regarding mental health is suspected, or developmental disability is unclear or not officially diagnosed, please contact Front Door  to access services for children and youth.

Parents who want to know about Front Door website,, call (519)749-2932 to book an appointment, or attend a walk-in counselling session at one of the walk-in locations.

Wed 12 pm to 7:30 pm
Last appointment at 6:30
1770 King St. E. Unit 1
Kitchener, ON

Thurs. 12 pm to 5:30 pm
Last appointment at 4:30
Langs – 1145 Concession Rd
Cambridge, ON



Links or Useful Resources for DUAL / CONCURRENT / CO-MORBID DIAGNOSES:
Canadian Mental Health Association -
Child & Parent Resource Institute -  or call 1-519-858-2774
Developmental Services Resource Centre – Waterloo Region (DSRC) – 519-741-1121 or
Developmental Services Ontario – or 519-741-1121
KidsAbility Centre For Child Development - or 519-886-8886
KidsLINK ( a program of Carizon)- via Front Door or access through Front Door – 519-749-2932
Mayo Clinic -
 Waterloo Region Family Network - or 519-804-1786