Evaluation of learning difficulty and cognitive delay

Overview 
Theory 
Emergencies 
Diagnosis 
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Evidence last reviewed: 13 May 2026

Topic last updated: 10 Jun 2026

Intellectual disability may be either generalized (cognitive impairment) or specific to one area (learning difficulty). Although the terms "cognitive impairment" and "learning difficulty" have specific definitions, they are sometimes used interchangeably by clinicians.[1]

Children with cognitive impairment have below-average IQ, at <70.[1] The degree of cognitive impairment depends on the underlying disorder and its severity.

Children with a specific learning difficulty have difficulties with particular mental tasks disproportionate to overall IQ. In some cases, IQ may be within the average or above-average range, while in others the IQ may be below-average. One or more areas of cognition may be impacted to a degree greater than expected based on IQ. Examples include difficulties with speech (specific language impairment), reading and writing (dyslexia), and use of numbers (dyscalculia).

Epidemiology

The prevalence of developmental intellectual disability is estimated to be between 0.22% and 1.55% of children, globally.[2] Cognitive impairment affects 2% to 3% of children.[3]

Down syndrome and fetal alcohol spectrum disorder are commonly identified congenital causes of cognitive impairment.[4] More recently, the number of genetic changes implicated in syndromic and nonsyndromic cognitive disability has expanded significantly.[5] Childhood exposure to environmental toxins, such as heavy metals (e.g., lead, arsenic, mercury), particulate air pollution, and pesticides, has been implicated in the etiology of neurodevelopmental disorders.[6][7][8][9]

The prevalence of learning difficulties is more difficult to determine because of the spectrum of disabilities and the variation in diagnostic criteria.[10] Most estimates suggest that the lifetime prevalence of learning disability is about 10%; males are more likely to be affected than females. Dyslexia is the most common specific learning disability (affecting about 5% to 12% of children).[1][2][11]

The majority of conditions associated with both specific learning difficulties and generalized cognitive impairment are developmental in origin, are linked to abnormalities in brain structure and function, and are present from birth or early childhood (i.e., prior to age 2-3 years). Learning difficulty or cognitive impairment may be part of a syndrome, and there may be a family history of similar difficulties.

Generalized cognitive impairment is often associated with a history of delayed developmental milestones; the age at which it becomes manifest varies according to its severity. In some children, mild generalized cognitive impairment becomes more obvious when the child starts attending school.

The English Learning Disabilities Mortality Review (LeDeR) program, in 2018, found that the median age at death for 3860 people with learning disabilities (ages 4 years and over) was 60 years for males and 59 years for females.[12]

Multidisciplinary team approach

Children who develop new specific learning difficulties or who have recently been identified as having cognitive impairment should be referred to a pediatric neurologist. An acquired disability due to intracranial pathology must be considered if there is an acute onset or a regression of previously acquired skills. However, often the specific learning difficulties or cognitive impairment may have been present for some time but only recently noted (e.g., on starting school).

A multidisciplinary team (MDT) assessment is desirable for accurate diagnosis and advice regarding appropriate interventions and educational placement. An MDT assessment includes the pediatrician or child psychiatrist and allied professionals such as a psychologist and a speech therapist. Children with motor coordination difficulties (developmental coordination disorder, or dyspraxia) resulting in physical problems with writing may benefit from assessment by an occupational therapist. The role of the clinical psychologist is to identify the child's cognitive ability (IQ, or age-equivalent developmental level, which can be compared with their chronologic age). Speech therapists help assess the child's expressive and receptive (understanding) language abilities and compare these with the overall level of cognitive ability. Some children have a discrepancy between cognitive and language abilities. For example, children with autism spectrum disorder (ASD) sometimes have relatively superior nonverbal skills compared with verbal performance.

There is evidence that early reading interventions may be particularly helpful in improving expressive and receptive language as well as reading in children with intellectual disability.[13] In children who have language or communication disorders, an Alternative Augmentative Communication (AAC) evaluation may be helpful in identifying appropriate modalities to improve functional communication.[14][15][16]

Globally, in 2021, an estimated 61.8 million people were believed to be on the autism spectrum.[17] Early diagnosis of ASD and intervention may, potentially, improve social and communication skills and adaptive behavior.[16][18][19] However, evidence to support screening programs for ASD in young children is limited.[20]

Children with neurodevelopmental disabilities may benefit from specialized support in transitioning to adulthood and adults with intellectual disabilities may benefit from targeted intervention to reduce long-term medical morbidity.[21][22]

Cerebral palsy

Cerebral palsy is a diagnosis given to children with a static brain injury of varying etiology (e.g., preterm birth, hypoxic-ischemic injury, meningitis, or intracerebral hemorrhage), associated with a disorder of movement and posture. Cerebral palsy is not a cause of cognitive impairment and refers solely to motor symptoms. However, the two conditions can coexist, and for this reason a cause and effect relationship is often mistakenly assumed both by clinicians and by the general public.[23]

Differentials

Common

Dyslexia
Attention deficit hyperactivity disorder (ADHD)
Down syndrome (trisomy 21)
Fragile X syndrome
Tuberous sclerosis
Autism spectrum disorder
Fetal alcohol spectrum disorder
Absence epilepsy
Childhood epilepsy with centrotemporal spikes (CECTS)
Social (pragmatic) communication disorder

Full details

Uncommon

Dyscalculia
Specific language disorder
Central auditory processing disorder (CAPD)
Developmental coordination disorder/dyspraxia
Myotonic dystrophy type 1 (DM1)
Prader-Willi syndrome
Angelman syndrome
Williams syndrome
Rett syndrome
DiGeorge syndrome (velocardiofacial syndrome)
Phelan-McDermid syndrome
Turner syndrome
Craniosynostosis
Congenital cytomegalovirus
Congenital toxoplasmosis
Congenital rubella
Teratogenic drugs
Heavy metal exposure
Exposure to environmental pollutants
Preterm birth
Perinatal hypoxic-ischemic injury
Bacterial meningitis
Encephalitis
Brain tumor
Traumatic brain injury
Hypoxia/asphyxia
Perinatal stroke
Congenital hypothyroidism
Inborn errors of metabolism
Psychosocial deprivation
Acquired epileptic aphasia (Landau-Kleffner syndrome)
Epileptic encephalopathies
15q11 duplication syndromes
16p11.2 deletion/duplication syndrome
Klinefelter syndrome
Xeroderma pigmentosum

Full details

Contributors

Authors

Kevin A. Shapiro, MD, PhD

Co-Director, Cortica Innovation Network

Cortica Healthcare, Inc.

Los Angeles, CA

Disclosures

KS is Co-Director of the Cortica Innovation Network and is employed by Cortica Healthcare. He has served as principal investigator for clinical trials of therapeutic interventions and diagnostic tools for autism, attention deficit-hyperactivity disorder, and Tourette syndrome, which were conducted at Cortica and sponsored by Acadia Pharmaceuticals, Akili Interactive, Axial Therapeutics, EarliTec Diagnostics, Emalex Biosciences, Floreo, and Noema Pharma. He was an external advisor for Novo Nordisk on the eTHINK study (Evolving Treatment of Hemophilia's Impact on Neurodevelopment, Intelligence, and Other Cognitive Functions). He has given expert testimony on topics related to autism, attention deficit-hyperactivity disorder, cognitive disability, and learning disabilities.

Acknowledgements

Dr Kevin A. Shapiro would like to gratefully acknowledge Dr Jeremy Parr, the previous contributor to this topic.

Disclosures

JP declared no competing interests.

Peer reviewers

Paul Gringras, MB ChB, MSc, MRCPCH

Consultant in Paediatric Neurodisability

Evelina Children's Hospital

St Thomas' Hospital

London

Disclosures

PG declares that he has no competing interests.

Sandra H. Jee, MD, MPH

Assistant Professor of Pediatrics

Department of Pediatrics

Research Director

Starlight Pediatrics

University of Rochester Medical Center

Rochester, NY

Disclosures

SHJ declares that she has no competing interests.

Peer reviewer acknowledgements

BMJ Best Practice topics are updated on a rolling basis in line with developments in evidence and guidance. The peer reviewers listed here have reviewed the content at least once during the history of the topic.

Disclosures

Peer reviewer affiliations and disclosures pertain to the time of the review.

References

Our in-house evidence and editorial teams collaborate with international expert contributors and peer reviewers to ensure that we provide access to the most clinically relevant information possible.

Key articles

American Psychiatric Association. Diagnostic and statistical manual of mental disorders, 5th ed., text revision (DSM-5-TR). Washington, DC: American Psychiatric Publishing; 2022.

Rodan LH, Stoler J, Chen E, et al. Genetic evaluation of the child with intellectual disability or global developmental delay: clinical report. Pediatrics. 2025 Jul 1;156(1):e2025072219.Full text Abstract

Mithyantha R, Kneen R, McCann E, et al. Current evidence-based recommendations on investigating children with global developmental delay. Arch Dis Child. 2017 Nov;102(11):1071-6.Full text Abstract

Reference articles

A full list of sources referenced in this topic is available to users with access to all of BMJ Best Practice.

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Evaluation of learning difficulty and cognitive delay

Summary

Epidemiology

Multidisciplinary team approach

Cerebral palsy

Differentials

Common

Uncommon

Contributors

Authors

Kevin A. Shapiro, MD, PhD

Disclosures

Acknowledgements

Disclosures

Peer reviewers

Paul Gringras, MB ChB, MSc, MRCPCH

Disclosures

Sandra H. Jee, MD, MPH

Disclosures

Peer reviewer acknowledgements

Disclosures

References

Key articles

Reference articles

A full list of sources referenced in this topic is available to users with access to all of BMJ Best Practice.

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