The phenomenology of autistic regression: subtypes and associated factors.

This study aimed to investigate the association of autistic regression (AR) and subtypes of AR with medical, developmental and psychiatric factors. Fifty-seven children with autistic spectrum disorders (ASD) were included in the study. Two types of AR are defined as regression after a normal social/language development (type 1) and regression as the worsening of previously reported autistic features (type 2). The frequency of history of AR was 56.1%. Male gender and sleep problems were found to be associated with a positive history of AR. The frequency of gastrointestinal complaints/diseases was higher in children with regression type 2 when compared to the children with regression type 1. Future studies with larger sample size and prospective design will contribute to clarifying the phenomenology and the associated factors of AR.