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A Diagnosis That Clarifies, Not a Label That Diminishes
The diagnosis is not a conclusion about a person’s worth. It clarifies a cognitive and adaptive profile so the person, their family, and care providers can adjust expectations, choose the right tools, and access relevant services. Each person who receives a diagnosis remains, first and foremost, a person, with their own personality, interests, relationships, and aspirations. The assessment documents a profile, not an identity.
Intellectual Disability Assessment in Montréal
Providing a clear diagnosis to support the person's independence.
Intellectual disability is characterized by significant limitations in both cognitive functioning and adaptive functioning. The clinical assessment documents each dimension rigorously and opens access to services that support the person and their family.
Clinical Definition
Intellectual Disability According to the DSM-5
Intellectual disability, referred to as intellectual developmental disorder in the DSM-5, is a neurodevelopmental disorder characterized by significant limitations in both intellectual functioning and adaptive functioning. The diagnosis assumes that both dimensions are affected, and that these limitations appear during the developmental period. The current term, intellectual developmental disorder, reflects the evolution of clinical understanding, which is no longer limited to intelligence quotient and fully recognizes the importance of adaptive skills in the diagnosis.
The Two Components
Intellectual Functioning and Adaptive Functioning
The DSM-5 requires that limitations be present in both dimensions to establish a diagnosis of intellectual disability. The first dimension, intellectual functioning, is measured using Wechsler scales such as the WISC-V for children and the WAIS-IV for adults. A score of two standard deviations below the mean is the usual threshold for a significant limitation.
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Adaptive Skills in Daily Life
The second dimension, adaptive functioning, is measured using tools such as the ABAS, administered with a parent or close family member. It documents three main domains, namely conceptual, social, and practical skills. Everyday communication, social skills, personal independence, academic or work skills, and safety are all assessed. It is the combination of both dimensions that clarifies the diagnosis and guides concrete recommendations.
Levels of Severity
Three Clinical Profiles Frequently Encountered
Severity is determined based on adaptive functioning and the level of support required for daily activities, not on intelligence quotient alone.
Mild Intellectual Disability
The most common level. The person can develop many academic and work-related skills with appropriate support. In adulthood, independent living is possible in several areas. Challenges often involve abstract reasoning, complex planning, and some of the more nuanced social skills.
Moderate Intellectual Disability
Academic learning progresses more slowly and requires adapted teaching. In adulthood, the person may hold a job with supervision, maintain meaningful relationships, and carry out many daily activities with appropriate support.
Severe Intellectual Disability
Significant, ongoing support is required for daily activities. Language remains limited, though it is still present in many cases, and communication may rely in part on non-verbal means. Learning focuses on practical and communication skills, and support aims at well-being, quality of life, and participation in family and community life.
After the Diagnosis
Access to Services and Support Programs in Québec
A formal diagnosis of intellectual disability opens access to several services within QuĂ©bec’s public network. Through their specialized intellectual disability (ID) and intellectual disability with autism spectrum disorder (ID-ASD) teams, the integrated health and social services centres offer support that includes educational assistance, social integration, residential support, and services for the family. In the school setting, the clinical report supports the development of an individualized intervention plan and access to adapted classes or resources. Financial support programs also exist, such as the federal Child Disability Benefit or the provincial Supplement for Handicapped Children. The assessment report is the reference document required to initiate most of these processes.
Signs During Development
What May Prompt an Assessment
Here are signs frequently observed that may justify a clinical assessment, from early childhood through adulthood.
- Overall delay in reaching developmental milestones such as walking, language, or toilet training
- Persistent learning delay at school that affects several subjects rather than a single skill
- Marked difficulty understanding complex instructions or reasoning about abstract concepts
- Social skills that remain clearly below those of same-age peers
- Limited independence in age-appropriate daily activities, such as dressing, eating, or moving around independently
- In adults, persistent difficulty living independently that is not explained by a mental health condition or a learning disability
- A referral for assessment from the school setting, a physician, or another care provider
- A need to document the profile in order to access specialized services or an intervention plan
The Assessment in Practice
What the Intellectual Disability Assessment Includes
The assessment combines measures of intellectual functioning and adaptive functioning, in accordance with DSM-5 criteria.
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Clinical Interview and Developmental History
Detailed documentation of motor, cognitive, language, and social development since early childhood. Collection of observations from family, school, and medical sources. Exploration of current difficulties and support needs.
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Assessment of Intellectual Functioning
Administration of an age-appropriate Wechsler scale. The WISC-V is used for children and adolescents. The WAIS-IV is used for adults. The analysis goes beyond the overall score to describe the complete cognitive profile.
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Assessment of Adaptive Functioning
Administration of a standardized adaptive skills scale, such as the ABAS, which documents conceptual, social, and practical skills. The interview is conducted with a parent, spouse, or close family member who knows the person being assessed well.
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Integrated Analysis and Report
Synthesis of both dimensions to confirm or rule out the diagnosis, specify the level of severity when applicable, and formulate recommendations tailored to the identified support needs. The report is written in language accessible to the family and to care providers.
Before you consult
The Most Frequently Asked Questions About the Assessment
If your question isn’t on this list, reach out directly to discuss it.
Intellectual disability, referred to as intellectual developmental disorder in the DSM-5, is a neurodevelopmental condition characterized by significant limitations in intellectual functioning and adaptive functioning, appearing during the developmental period. Diagnosis requires the presence of both dimensions, documented using standardized tools.
The process combines an in-depth clinical interview, an assessment of intellectual functioning using a Wechsler scale, and an assessment of adaptive functioning using a standardized scale such as the ABAS. Integrating both dimensions makes it possible to confirm or rule out the diagnosis and clarify the severity level when applicable. The report is presented during a videoconference meeting.
Clinically, intellectual disability is described as mild, moderate, or severe depending on the level of support required in daily life. Severity is determined based on adaptive functioning rather than intelligence quotient, since it is the level of day-to-day support needed that guides services and recommendations.
Yes. An assessment in adulthood is possible, and sometimes necessary, when the diagnosis was not made during childhood. It documents current cognitive and adaptive functioning and establishes continuity with the developmental period based on the account provided by the person and their loved ones. A diagnosis in adulthood can open access to support services.
The clinical report serves as the reference document for the next steps. It can support a request for services from the specialized ID and ID-ASD teams at the centres intégrés de santé et de services sociaux, help put a school intervention plan in place, or accompany a request for government benefits. Next steps are discussed when the results are presented.
Most private insurance plans partially or fully cover assessments carried out by a psychologist who is a member of the Ordre des psychologues du Québec. Fees are eligible for the federal and provincial medical expense tax credit. The exact terms vary from plan to plan and should be confirmed with your insurer before the first appointment.