Study confirms high, but stable, child autism rate
Concerns over an "epidemic of autism" may ease thanks to research by MUHC investigators. The study, published in the American Journal of Psychiatry this month, reveals that although pervasive development disorders such as autism are more common than previously believed they are not increasing.
"Our initial study, conducted between 1992 and 1995, revealed that 0.63% of children surveyed suffered a pervasive development disorder," says Dr. Eric Fombonne, one of the study's authors and Director of the Department of Psychiatry at the Montreal Children's Hospital and Head of the Division of Child Psychiatry at McGill University. "This result was triple the autism rate of 30 years ago." The new study aimed to replicate this research, using subsequent cohorts of children under the same experimental conditions, to establish whether autism is on the rise.
The new study, which involved 10,903 preschool children in the United Kingdom, confirmed the elevated autism rate, but clearly demonstrated that autism prevalence is not increasing. "This study provides the most robust estimate of childhood autism to date, and suggests that epidemic concerns are unfounded," says Dr. Fombonne.
Health researchers are unsure what causes pervasive development disorders such as autism; suggested causes range from childhood vaccinations to pregnancy complications, but genetic factors exert a paramount influence. "Today's higher autism rate — which is comparable to estimates gathered as part of an upcoming study on Montreal children — could simply be a result of better diagnosis and awareness," says Dr. Fombonne. "Although it is reassuring that autism is not on the rise, this study also shows that one in 165 children is affected with a pervasive development disorder, which has strong implications on services."
The Montreal Children's Hospital is the pediatric teaching hospital of the McGill University Health Centre (MUHC). The institution is a leader in the care and treatment of sick infants, children and adolescents from across Quebec. The Montreal Children's Hospital provides a high level and broad scope of health care services, and provides ultra-specialized care in many fields, including cardiology and cardiac surgery; neurology and neurosurgery; traumatology; genetic research; psychiatry and child development; and musculoskeletal conditions, including orthopedics and rheumatology. Fully bilingual and multicultural, the institution respectfully serves an increasingly diverse community in more than 50 languages.
The McGill University Health Centre (MUHC) is a comprehensive academic health institution with an international reputation for excellence in clinical programs, research and teaching. The MUHC is a merger of five teaching hospitals affiliated with the Faculty of Medicine at McGill University — the Montreal Children's, Montreal General, Royal Victoria, and Montreal Neurological Hospitals, as well as the Montreal Chest Institute. Building on the tradition of medical leadership of the founding hospitals, the goal of the MUHC is to provide patient care based on the most advanced knowledge in the health care field, and to contribute to the development of new knowledge.