Children with Intellectual Disability

Intellectual Disability (ID) is defined as deficits in intellectual functioning and adaptive behaviors.  The severity of ID is defined differently by DSM-5 and the American Association on Intellectual and Developmental Disabilities (AAIDD).  The AAIDD classifies ID severity by the level of support needed by the individual: intermittent, limited, extensive and pervasive support.  DSM-5 classifies ID severity as mild, moderate, severe, and profound according to functional deficits in 3 domains: conceptual (cognitive), social (interpersonal) and practical (activities of daily living).  

The diagnosis of ID generally requires a multidisciplinary assessment of intellectual and adaptive functioning.  The diagnosis should be followed up with an investigation of etiology.  

Etiologic categories for ID include X-linked syndromes, deletion syndromes, syndromes of imprinting/uniparental disomy, syndromes of nondisjunction, ciliopathies, prenatal alcohol exposure, inborn errors of metabolism, and early childhood lead poisoning. 

The American College of Medical Genetics (ACMG) provides guidelines for cytogenic testing for individuals with ID.  While the ACMG does not recommend routine testing for inborn errors of metabolism, the pediatric clinician should check that newborn screening tests were performed.  Neuroimaging is generally reserved for patients with neurological findings including microcephaly, macrocephaly or seizures.  

Psychiatric comorbidity

The differential diagnosis for new-onset or chronic behavioral symptoms in children with ID includes:

  • Medical problems such as otitis media, constipation, GERD, dental pain, menstrual pain or distress, or injuries
  • Neuropsychological profile of the disorder with which ID is associated: Many genetic and metabolic disorders causing ID have a neuropsychological profile that includes hyperactivity, inattention, poor inhibitory control, learning problems, and executive functioning deficits.  The spectrum of disorders associated with fetal alcohol exposure includes a tendency to repeat the same mistakes and inability to learn routines.  While these symptoms may overlap with psychiatric diagnoses, they may not respond to pharmacologic or behavioral therapies in the same way that they do in typically developing children. 
  • Communication: being unable to communicate verbally or through augmented communication can be frustrating.  Children with ID may lash out behaviorally when they cannot make their needs or preferences known.  
  • Behavioral reinforcement: Behaviors that persist tend to be self-reinforcing.  Children with ID may have decreased problem-solving skills.  Behaviors will be reinforced if they:
    • Are positively reinforced – they result in attention, access to preferred items, activities or people
    • Are negatively reinforced – they result in escape from or avoidance of unwanted experiences
    • Are internally reinforced – they are self-stimulating, or reduce pain, or provide comfort
  • Medication side effects: Stimulants, antiepileptics, muscle relaxants, centrally acting antiemetics and other medications can have behavioral side effects.
  • Cognitive and sensory factors:  A mismatch between academic or performance expectations and a child’s cognitive or adaptive abilities can be stressful and present as behavioral disturbance.  Individuals with ID may have sensory sensitivities and can be overwhelmed in environments with excessive noise, light, or other stimuli.  
  • Environmental and psychosocial factors: Children and adolescents with ID will generally do best in predictable environments where they can be expected to function at their developmental level.  Many individuals with ID are sensitive to changes in environment or routine and will exhibit behavioral symptoms if these occur.  
  • Children and adolescents with ID are at high risk for bullying, trauma and abuse

Assessing psychiatric disorders in children and adolescents with ID is complicated by the lack of measurement validity of commonly used assessment tools in the ID population.  There may also be clinically significant symptom clusters that do not meet full criteria for a psychiatric disorder that are more common among individuals ID than those without.  

A recent systematic review found the most prevalent conditions in children and adolescents with ID to attention deficit/hyperactivity disorder (30%), conduct disorders (3-21%) and anxiety disorders (7-34%) (Buckley et al 2020). 

Treatment strategies

Because individuals with ID are often excluded from controlled trials of psychotherapeutic and psychopharmacologic treatments, the evidence base for these treatments in populations with ID is limited.

Psychotherapeutic treatments

Communication interventions including alternative and assistive communication and Functional Communication Training have been found highly effective in reducing challenging behaviors. 

Applied Behavioral Analysis is an intensive therapy that examines the antecedents and reinforcers of problematic behaviors and works with patients and caregivers in reducing these with behavioral strategies.  ABA has been found effective in youth with ID with and without Autism Spectrum Disorder.

Cognitive Behavioral Therapy can be adapted for use with youth with ID who have sufficient communication and cognitive skills to address mood, anxiety, and behavioral symptoms. 

Psychotropic medications

First-line psychotropic medication strategies used in primary care pediatrics are generally appropriate for the treatment of inattention and hyperactivity (methylphenidate), anxiety or depression (SSRIs) and severe irritability or aggression (risperidone). 

Monitoring parental mental health

Parents of children with developmental disabilities including ID and Autism Spectrum Disorder are at high risk for developing psychological distress, anxiety, depression, or dissatisfaction with life.   This may be particularly true if the child has behavioral problems (Hoyle, Laditka & Laditka 2021).  

The pediatric clinician can support families of children with ID and other chronic conditions.  A first step is simply acknowledging the challenges that family is facing and checking in on family well-being.  The American Board of Pediatrics Roadmap Project begins with the question, “How are you doing?”.  The emphasis in the question is in really wanting to know the answer.  

“It seems like Jimmy’s behavior has been a challenge lately, and then he had all these problems with constipation. You are doing an amazing job keeping up with it all. How are you doing?”

Simply hearing that their role in caring for their child is acknowledged and appreciated, being addressed as a member of their child’s treatment team and being seen as an individual with strengths and needs can make a difference for parents.  

Other supports may include referrals to mental health services or to Parent Management Training.  A recent study from Iran found that mothers of children with ID who participated in a positive parenting program had improvement in somatic symptoms, anxiety, depression and social dysfunction (Ashori, Norouzi, & Jalil-Abkenar 2019).


Practice Parameter for the Assessment and Treatment of Psychiatric Disorders in Children and Adolescents ith Intellectual Disability (pdf) AACAP 2020

Ashori, M., Norouzi, G., & Jalil-Abkenar, S. S. (2019). The effect of positive parenting program on mental health in mothers of children with intellectual disability. Journal of Intellectual Disabilities, 23(3), 385–396.

Buckley, N., Glasson, E. J., Chen, W., Epstein, A., Leonard, H., Skoss, R., Jacoby, P., Blackmore, A. M., Srinivasjois, R., Bourke, J., Sanders, R. J., & Downs, J. (2020). Prevalence estimates of mental health problems in children and adolescents with intellectual disability: A systematic review and meta-analysis. Australian & New Zealand Journal of Psychiatry, 54(10), 970–984.

Einfeld, S. L., Ellis, L. A., & Emerson, E. (2011). Comorbidity of intellectual disability and mental disorder in children and adolescents: A systematic review. Journal of Intellectual & Developmental Disability, 36(2), 137–143.

Hoyle, J. N., Laditka, J. N., & Laditka, S. B. (2021). Mental health risks of parents of children with developmental disabilities: A nationally representative study in the United States. Disability and Health Journal, 14(2), 101020.

Maïano, C., Coutu, S., Tracey, D., Bouchard, S., Lepage, G., Morin, A. J. S., & Moullec, G. (2018). Prevalence of anxiety and depressive disorders among youth with intellectual disabilities: A systematic review and meta-analysis. Journal of Affective Disorders, 236, 230–242.