Many adults with autism have complex needs. Those needs only become more complex when their autism occurs alongside another condition, with intellectual disability being one of the most common co-occurring diagnoses. Adults with intellectual disabilities and autism may show signs of both conditions in different ways, meaning support may need to be adjusted accordingly.
What is autism?
Autism is a condition that covers a broad spectrum of traits and behaviours. No two people with autism are the same. However, there are a few indications and symptoms that are considered the condition’s core features. These include problems with communication and social contact, as well as repetitive or restricted behaviour. Sensory difficulties and poor motor abilities are other typical characteristics.
What is intellectual disability?
Many people think of intellectual disability as simply meaning that a person is not very intelligent. A diagnosis of intellectual disability, however, requires the individual to meet very specific diagnostic criteria. It comprises not only below-average intellectual performance (often defined as an IQ of less than 70, though there is some leeway), but also adaptive impairments, or trouble carrying out the daily tasks that are generally deemed necessary to function in the surrounding environment. Adaptive deficits may include issues with personal hygiene, problem-solving, money management or social skills, to give just a few examples. Both intellectual impairment and adaptive deficits must be displayed during the developmental period, generally under age eighteen.
Traits of adults with intellectual disabilities and autism together
People with autism are more likely to have an intellectual disability than the wider population. Causes may include a complex mix of biological and environmental factors. There are also some conditions, such as Fragile X syndrome and Phelan-McDermid syndrome, where both autism and intellectual disability are more common. Some traits, such as social and communication deficits, are common to both conditions, whilst other characteristics are unique. The combination of autism and intellectual disability may affect a child’s ability to learn and therefore their performance at school. This in turn can influence their ability to live independently as an adult, particularly in areas such as employment.
Adaptive functioning deficits in adults with intellectual disabilities and autism may mean they need ongoing support to deal with even basic daily tasks. They may find it much harder to learn new skills or remember important information. They may also struggle with general reasoning, and therefore have difficulty applying existing skills and knowledge in new situations. Increased language and communication deficits (especially for the non-verbal) could make it harder to interact with doctors or support workers, and therefore access appropriate assistance.
It may be considerably more difficult for people to manage the combined features of autism and intellectual disability if they did not get successful interventions as children. The regular difficulties with transitioning from child to adult services and the changing availability of support become even more pronounced.
The high degree of overlap between adults with autism and adults with intellectual disabilities, and the blurred line between the two, means it is significant to understand the signs and symptoms of both these conditions and how they interact. That will better enable diagnosis and the provision of appropriately tailored and individualized support.