Autism is a very confusing diagnostic label.
The term is used both for a more specific syndrome of abnormal development and also for a much broader range of related disorders. As their causes are not yet known for sure, these disorders are defined in terms of sets of behavioural symptoms which are not the same in every affected person. If we were to enter a room full of persons who had been diagnosed with autism, we would be struck far more by the differences than by the similarities among them. After a great deal of research interest during the 1990s, we can now understand several things about autism more clearly. There is general agreement that, in its full-blown form, autism involves a triad of impairments in social interaction, in communication and the use of language, and in limited imagination as reflected in restricted, repetitive and stereotyped patterns of behaviour and activities.