Autism is the most severe childhood neuropsychiatric condition. Childhood autism, is a complex developmental disability, with onset of symptoms that typically appear during the first 3 years of childhood and continue throughout life. Nearly 75-80% of individuals with childhood autism functional at the mental retarded level. Atypical autism is sometimes loosely interchanged with the label of high functioning autism to denote milder version of autism. Autism has become one of the most widespread childhood epidemics in recorded history. Early views of childhood autism were focused on psychogenic causes such as deficient parent child interaction and parental psychopathology. In year 2000 childhood autism conceptualize as biological disorder with multiple etiologies.