In the United Kingdom, the 1993 Education Act refers to ‘learning diffculties’: generalised (severe or moderate), or speci?c (e.g. DYSLEXIA, dyspraxia [or APRAXIA], language disorder). The 1991 Social Security (Disability Living Allowance) Regulations use the term ‘severely mentally impaired’ if a person suffers from a state of arrested development or incomplete physical development of the brain which results in severe impairment of intelligence and social functioning. This is distinct from the consequences of DEMENTIA. Though ‘mental handicap’ is widely used, ‘learning disability’ is preferred by the Department of Health.
There is a distinction between impairment (a biological de?cit), disability (the functional consequence) and handicap (the social consequence).
People with profound learning disability are usually unable to communicate adequately and may be seriously movement-impaired. They are totally dependent on others for care and mobility. Those with moderate disability may achieve basic functional literacy (recognition of name, common signs) and numeracy (some understanding of money) but most have a life-long dependency for aspects of self-care (some fastenings for clothes, preparation of meals, menstrual hygiene, shaving) and need supervision for outdoor mobility.
Children with moderate learning disability develop at between half and three-quarters of the normal rate, and reach the standard of an average child of 8–11 years. They become independent for self-care and public transport unless they have associated disabilities. Most are capable of supervised or sheltered employment. Living independently and raising a family may be possible.
Occurrence Profound learning disability affects about 1 in 1,000; severe learning disability 3 in 1,000; and moderate learning disability requiring special service, 1 per cent. With improved health care, survival of people with profound or severe learning disability is increasing.
Causation Many children with profound or severe learning disability have a diagnosable biological brain disorder. Forty per cent have a chromosome disorder – see CHROMOSOMES (three quarters of whom have DOWN’S (DOWN) SYNDROME); a further 15 per cent have other genetic causes, brain malformations or recognisable syndromes. About 10 per cent suffered brain damage during pregnancy (e.g. from CYTOMEGALOVIRUS (CMV) infection) or from lack of oxygen during labour or delivery. A similar proportion suffer postnatal brain damage from head injury – accidental or otherwise – near-miss cot death or drowning, cardiac arrest, brain infection (ENCEPHALITIS or MENINGITIS), or in association with severe seizure disorders.
Explanations for moderate learning disability include Fragile X or other chromosome abnormalities in a tenth, neuro?bromatosis (see VON RECKLINGHAUSEN’S DISEASE), fetal alcohol syndrome and other causes of intra-uterine growth retardation. Genetic counselling should be considered for children with learning disability. Prenatal diagnosis is sometimes possible. In many children, especially those with mild or moderate disability, no known cause may be found.
Medical complications EPILEPSY affects 1 in 20 with moderate, 1 in 3 with severe and 2 in 3 with profound learning disability, although only 1 in 50 with Down’s syndrome is affected. One in 5 with severe or profound learning disability has CEREBRAL PALSY.
Psychological and psychiatric needs Over half of those with profound or severe – and many with moderate – learning disability show psychiatric or behavioural problems, especially in early years or adolescence. Symptoms may be atypical and hard to assess. Psychiatric disorders include autistic behaviour (see AUTISM) and SCHIZOPHRENIA. Emotional problems include anxiety, dependence and depression. Behavioural problems include tantrums, hyperactivity, self-injury, passivity, masturbation in public, and resistance to being shaved or helped with menstrual hygiene. There is greater vulnerability to abuse with its behavioural consequences.
Respite and care needs Respite care is arranged with link families for children or sta?ed family homes for adults where possible. Responsibility for care lies with social services departments which can advise also about bene?ts.
Education Special educational needs should be met in the least restrictive environment available to allow access to the national curriculum with appropriate modi?cation and support. For older children with learning disability, and for young children with severe or profound learning disability, this may be in a special day or boarding school. Other children can be provided for in mainstream schools with extra classroom support. The 1993 Education Act lays down stages of assessment and support up to a written statement of special educational needs with annual reviews.
Pupils with learning disability are entitled to remain at school until the age of 19, and most with severe or profound learning disability do so. Usually those with moderate learning disability move to further education after the age of 16.
Advice is available from the Mental Health Foundation, the British Institute of Learning Disabilities, MENCAP (Royal Society for Mentally Handicapped Children and Adults), and ENABLE (Scottish Society for the Mentally Handicapped).
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