Since specific biological indicators have yet to be discovered, autism is currently defined merely in terms of the behavioural models it displays. These characteristics are outlined in the generally-accepted international diagnosis and classification systems, such as the DSM IV, compiled by the American Psychiatric Association and the ICD 10, created by the World Health Organisation. Although imperfect, these classifications are nevertheless reviewed periodically in order to enable the incorporation of new data provided by the latest research, and are essential for perfecting the art of individual clinical diagnosis in our field.

The aim of this description of autism is not to replace those classifications mentioned above, but rather to complement them, going beyond mere diagnosis and taking into account other aspects that anyone interested in the theme will find useful when facing the challenge posed by this illness. This document has been compiled within the limits of our current knowledge, and future findings and research will no doubt necessitate its revision.

Although further research is required to gain a better understanding of the exact cause of autism, there can be no doubt that the illness contains a multi-factorial genetic or hereditary element, and that its origin is related to a number of different organic causes. These causes are diverse in nature, reflecting the diversity of those suffering from the illness, and affect common neuropsychological and physiopathological mechanisms that are the essential prerequisites for autism.

In turn, these mechanisms are influenced by diverse environmental and personal factors which result in a series of variations within the essential clinical characteristics of the disorder. Given that autism is basically a developmental alteration, its specific manifestation will vary considerably depending on age and experience.

As this description maintains, the clinical diagnosis of the disorder should serve as an indicator towards progress rather than a negative label, and should lead to a recognition of the peculiar qualities and needs of each individual. Although there are certain key elements which appear in all the most efficient programmes, there is nevertheless a wide range of possible therapies, many of which may prove useful in relation to specific problems or specific individuals. All these possibilities should be taken into consideration when developing personalised support plans.

These plans should in turn be constantly reviewed and supervised in order to ensure their effectiveness and adaptation to the development and circumstances of the person at whom they are directed. Each individual is a member of a family, and in a wider sense of society as well. All parties involved in the plan need to be encouraged and supported in their efforts to obtain an environment which favours the development of those affected by autism, thereby ensuring their happiness and the quality of the lives they lead.