From the Guidelines
Yes, it is possible for a person to have both autism and Down syndrome simultaneously, a condition known as dual diagnosis. Down syndrome is a genetic condition caused by an extra copy of chromosome 21, while autism is a neurodevelopmental disorder characterized by differences in social communication and behavior patterns. Research suggests that individuals with Down syndrome have a higher likelihood of meeting the diagnostic criteria for autism compared to the general population, with estimates ranging from 5-10% of people with Down syndrome also having autism 1. The diagnosis can be challenging because some developmental features of Down syndrome may overlap with autism characteristics. For individuals with both conditions, treatment approaches typically combine strategies used for each condition separately, including speech therapy, occupational therapy, behavioral interventions, and educational supports tailored to address the specific needs arising from both conditions.
Key Considerations
- Early intervention is particularly important to support development across all domains.
- Families may need additional support to navigate the unique challenges presented by this dual diagnosis, as the combination can result in more complex developmental and behavioral profiles than either condition alone.
- A comprehensive assessment, including genetic testing and psychological evaluation, is crucial for diagnosing and managing individuals with dual diagnosis, as recommended by guidelines for the assessment and treatment of children and adolescents with autism spectrum disorder 1.
Management and Support
- Treatment plans should be individualized to address the specific needs of each person with dual diagnosis.
- A multidisciplinary approach, involving healthcare providers, therapists, and educators, is essential for providing comprehensive support and care.
- Regular screening for co-occurring medical conditions, such as hypothyroidism, leukemia, and sleep apnea, is necessary for individuals with Down syndrome, as highlighted in guidelines for the management of adults with congenital heart disease 1.
From the Research
Co-Occurrence of Autism and Down Syndrome
- Individuals with Down syndrome (DS) can also have autism spectrum disorder (ASD), with a prevalence rate of ~20% 2.
- The co-occurrence of DS and ASD presents diagnostic challenges, but refined methods in clinical evaluation can provide better diagnosis and understanding of the etiology of ASD in DS 3.
Characteristics of Individuals with Co-Occurring DS and ASD
- Individuals with co-occurring DS and ASD show strengths in behavioral functioning compared to those with intellectual disability, but have similar behavioral functioning to those with ASD and cognitive impairment 4.
- Cognitive functioning and ASD symptomatology are more comparable between individuals with co-occurring DS and ASD and those with ASD and cognitive impairment 4.
- Individuals with co-occurring DS and ASD have lower overall adaptive skills compared to other groups 4.
Implications for Clinical Practice
- Speech-language pathologists (SLPs) play a key role in supporting families of individuals with co-occurring DS and ASD by advocating and educating 2.
- Understanding the unique profiles of strengths and weaknesses of individuals with co-occurring DS and ASD can help SLPs provide appropriate service delivery and intervention approaches 2.
- Evidenced-based interventions for children with ASD can be applied to individuals with co-occurring DS and ASD, with consideration of individual differences and needs 5.