This is a four year research on the early onset of infantile autism.Based on a heuristic point of view on the diversity of autistic disorder, we will discuss thedifferent types of autism and more precisely the onset of autism in a wide range ofdiseases.This study will first present the problems linked to the nosological demarcation betweennormality and pathology, then the difficulties linked to the diagnosis of autism.This theorical and clinical considerations are based on clinical observations and on thereview of the great works on autism.This heuristical progression leads our study, which is based on the question of the earlyinfantile autism according to the age of the individual. Two sub-groups have been studied:the first group comprises subjects with Early Onset Autism, and the second groupcomprises subjects with Late Onset Autism.The confirmation that there are differences between those two groups and the discoverythat both groups have their own development particularities enable us to discuss moreprecisely the role of autistic disorder in early infantile autism and in diseases with autisticdisorders, such as obsessive compulsive disorder.Our findings and discussion lead us to the following hypothesis: the main features ofautistic disorder, that is autism, could be the consequence of a pathological defence,which role, function, intensity and evolution could depend on underlying disorders. Thecategory of the disease could be determined by the age at which the subject develops it,and by his ability to fight against these disorders, his original fragility and theenvironmental obstacles he will face.
