Text adapted from "Intellectual and developmental disabilties" in Psychiatry in primary care by Yona Lunsky and Johanna Lake, (CAMH, 2019).
Screening questions and considerations
A developmental history is critical to determining whether your patient has IDD. In addition to speaking with a family member who knew the person from childhood, you can request access to school and clinical records. Typically, if significant cognitive impairments existed, this would be reflected in the courses the person took in school, possibly including special education support, as well as in any psychological reports in the school record (which is not automatically shared with the person’s physician). This type of documentation is very important when seeking services for IDD in adulthood because demonstrating that current impairments were present during the developmental period is required.
If you suspect IDD and do not have information on file, there are questions you can ask that facilitate screening. The Health Care Access Research and Developmental Disabilities Program (H-CARDD; 2016) suggests asking the following questions:
Education level: “Can you tell me about school?” “How old were you when you left?”
Daytime activity: “How do you spend your days?” “Do you receive any help in your job?”
Functional abilities: Ask the patient to tell you the time, or point to a sign and ask the patient to read it. Determine whether your patient is able to complete requisite paperwork. Also, ask about navigating the community; for example, “How did you get this appointment?” “How will you get home?”
Support level: “Can you tell me about where you live?” “Do you live with anyone else?” “Do you have a case manager?” “Would you like one?”
Screening for ASD
Screening for ASD in adulthood may involve:
- asking the patient and family members about early developmental history, current concerns
- using parent measures, such as the Social Communication Questionnaire (Rutter et al., 2003)
- using self-report measures, such as the Autism-Spectrum Quotient (Baron- Cohen et al., 2001). However, self-reports are generally designed for people with average or above-average intelligence. You can review the results of screening tools to determine whether to refer the patient to a specialist for assessment and diagnosis.
You may have a patient with an obvious disability, and your medical records may include the patient’s childhood records, such as developmental assessments covering etiology (genetic, environmental, pre- or perinatal) and cognitive and adaptive functioning. It is also possible that you may begin seeing a patient as an adult and not have information from childhood records.
Although one to three per cent of people have an intellectual disability, fewer than one per cent have this disability captured in their health or social service records in adulthood. Most disabilities are quite mild in nature and, particularly when other problems are present such as an addiction or serious mental illness, the disability may be missed.
While it was once thought that 70 to 80 percent of people with ASD had an intellectual disability, it is now recognized that over 50 percent do not have an intellectual disability. Many people, particularly women, have learned to “mask” their symptoms so others do not immediately identify them as having ASD. Because of changes in diagnostic criteria in recent years, many people with ASD are receiving this diagnosis for the first time in adulthood (Lai & Baron-Cohen, 2015). Thus, only some adults with ASD have grown up with this diagnosis and with a history of receiving appropriate medical, educational and social supports.