# Disorders of Intellectual Development - Category: chronic - Review status: reviewed (every claim checked against a document named on this page) - Sources: ICPC-3 (WONCA International Classification of Primary Care, 3rd edition) class PD18 - condition scope only, no dose · Intellectual Disability - StatPearls (NCBI Bookshelf NBK547654) - https://www.ncbi.nlm.nih.gov/books/NBK547654/ · No dose - referral pathway, no medicine given in primary care - Verified date: 2026-08 ## Verified against - No dose - referral pathway, no medicine given in primary care ## Treatment metadata - No drug therapy in primary care (Referral & Advice) ## Complete treatment card ```text DISORDERS OF INTELLECTUAL DEVELOPMENT Sources: ICPC-3 (WONCA International Classification of Primary Care, 3rd edition) class PD18 - condition scope only, no dose · Intellectual Disability - StatPearls (NCBI Bookshelf NBK547654) - https://www.ncbi.nlm.nih.gov/books/NBK547654/ · No dose - referral pathway, no medicine given in primary care Review status: REVIEWED against the source listed above (2026-08) IS IT THIS? - reference only, to read alongside your own examination SYMPTOMS - what the patient reports (4) - Self-feeding, toileting, and dressing can be difficult depending on severity - Getting along with family and friends is often hard due to communication problems and poor impulse control - Onset is usually in childhood or adolescence, with language or motor delays sometimes noticeable by age two - Many children with a mild degree of impairment go unrecognized until school age SIGNS - what you find (7) - Spasticity, low tone, hyperreflexia, or involuntary movements are common motor findings [hyperreflexia · involuntary movements · spasticity] - Slanted eyes, a flat nasal bridge, a protruding tongue, a small chin, and a single palmar crease suggest Down syndrome [dysmorphic features] - Fragile X syndrome shows an elongated face, a prominent forehead and jaw, big ears, and macroorchidism in boys [dysmorphic features] - A smooth philtrum, thin upper lip, and small palpebral fissures suggest fetal alcohol syndrome [dysmorphic features] - Compulsive-eating obesity, hypogonadism, and small hands and feet suggest Prader-Willi syndrome [obesity] - Microcephaly, widely spaced eyes, low-set ears, and a small jaw suggest cri-du-chat syndrome [dysmorphic features] - Odd hand-twisting movements with poor coordination and perceptual difficulty suggest phenylketonuria TESTS (10) - DSM-5 requires deficits in both intellectual and adaptive function with onset before age 22 - An IQ score of 70 or below, two standard deviations under the mean, suggests intellectual disability - Severity by IQ runs mild 50 to 70 (85% of cases), moderate 35 to 50 (10%), severe 20 to 35 (4%), and profound below 20 (1%) - An IQ below 70 with good adaptive function does not count as intellectual disability, and the reverse also holds - Chromosomal analysis by amniocentesis or CVS is highly specific for Down syndrome - A cell-free fetal DNA test offers a noninvasive prenatal screen for Down syndrome with a higher detection rate - FISH testing identifies microscopic chromosomal deletions - Urine and blood testing can detect inborn errors of metabolism such as PKU, Lesch-Nyhan, galactosemia, and Hurler syndrome - CT or MRI can identify microcephaly, cerebral developmental delay, and cerebral palsy - EEG can detect accompanying seizures, though the findings do not point to a specific diagnosis IF NOT THIS - what else fits (5) - Child abuse can cause developmental delays that, unlike true intellectual disability, often reverse once the environment improves - A debilitating chronic medical illness can cause depression and developmental delay in someone of normal intelligence - Cerebral palsy's poor coordination and vision, hearing, or speech problems can mimic intellectual disability - Undiagnosed deafness or blindness can produce a false-positive diagnosis on testing - Expressive or receptive aphasia from a speech disorder can be mistaken for intellectual disability Source StatPearls "Intellectual Disability" - disease-level clinical article Status traced to the source above 1. NO DRUG THERAPY IN PRIMARY CARE (REFERRAL & ADVICE) [1st line] Adult Arrested or incomplete development of intellectual abilities present from childhood, with impaired adaptive skills; there is no drug treatment for the condition itself, so the GP's role is early recognition, developmental referral, and management of any coexisting behavioural or psychiatric symptoms. - Refer, with advice Peds Children follow the same pathway: recognise and refer. No primary-care medicine is implied. Source No dose - referral pathway, no medicine given in primary care Why Arrested or incomplete development of intellectual abilities present from childhood, with impaired adaptive skills; there is no drug treatment for the condition itself, so the GP's role is early recognition, developmental referral, and management of any coexisting behavioural or psychiatric symptoms. Caution No medicine is prescribed for this in primary care - this entry is for recognition and referral. Anything given is decided by the service it is referred to. RED FLAG - Loss of skills the child had already gained, which suggests a different, progressive condition needing urgent work-up, or associated seizures or dysmorphic features suggesting an underlying syndrome: refer urgently. Prices are indicative (dataset snapshot 2026-06); verify with the pharmacy. ``` --- Dawaa Reference is a reference for prescribers, not a medical device, and does not replace clinical judgement. [Privacy policy](/privacy)