Learning Disabilities

Abstract

Learning disability or mental retardation refers to a global impairment in intellectual functioning, which is usually associated with decreased adaptive functioning. Impairment is lifelong, although individuals with learning disability may continue to acquire new skills and abilities into adult life. Prevalence rates vary from less than 1% to 10%, with many studies reporting rates of 3–5%. The majority of cases of severe learning disability are caused by genetic or other medical factors, with single gene and chromosomal disorders playing a prominent role. Genetic factors are also important in milder learning disability but these influences are likely to be due to multiple susceptibility genes acting together and probably in concert with environmental factors. People with learning disability are at increased risk for a wide range of physical and mental disorders. Some causes of learning disability are associated with a ‘behavioral phenotype’ in which a constellation of unusual behavioral and⧸or cognitive abilities is usually present. Clinical assessment requires determination of verbal and non-verbal cognitive functioning, history taking to elicit early development and medical problems as well as any current physical or mental problems, and physical examination for causes or consequences of specific disorders causing learning disability. It is uncommon to identify currently treatable cause of learning disability. Psychoeducation for parents and carers is key, as is appropriate educational placement and community support. Regular screening for physical and mental problems is important and treatment should be actively sought.