Introduction A confusing variety of terms has been used to describe people w ith w hat is now called learning disability. Terms such as idiocy and cretinism were replaced by subnorm ality and handicap. More recently, m ental handicap has been superseded by term s such as learning disability and learning difficulty. Some of these terms (i.e. im pairm ent, disability and handicap) have been defined by the W orld Health Organization (see Chapter 1), although they are also used in the M ental Health Act.