Developmental problems (DP) include a variety of quite prevalent conditions, associated
with psychomotor functions, and affect young children: vision and hearing disorders,
communication problems (language and learning disorders, autism), cerebral palsy,
mental retardation and behavioural disorders. They impose enormous personal, social and
economic costs as a result of their early onset and lifetime disability. Developing countries
are expected to have a higher prevalence of DP than developed countries.