Introduction

Many children, adolescents (and adults) have ‘learning problems’. Some need a lot of extra attention and support to be able to learn new things in fairly well-circumscribed areas, such as reading, writing and mathematics, but do not have similar needs in other areas. Such individuals should be considered for a diagnosis of a specific developmental disorder. Yet others appear to have problems in learning across the board. If they have not been identified as having a learning disability already in the first few years of life – in which case their learning disability is usually severe – it is high time to consider the possibility during the first school years.

Mental retardation (MR) – recently referred to as learning disability in the UK – is neither a medical condition, nor – strictly speaking – a medical diagnosis. It is not a psychiatric disorder, but is usually listed in psychiatric disorder diagnostic manuals. It is still often referred to as a ‘developmental disorder’, but even such terminology is inappropriate. While not basically a medical problem, MR has very strong links to medical conditions, and psychiatric and developmental disorder. MR as an important ‘knowledge niche’ of medicine was not acknowledged until about 150 years ago. In 1850, the first medical periodical devoted to MR was published (‘Observations on Cretinism’). Sixteen years later John Langdon Down wrote his landmark paper on the heterogeneous nature of mental retardation.