When does autism first appear?

For some time, based on parent reports and studies, we and others in the field have believed that the very high majority of children with moderate or severe autism start showing signs at either of two times: during their first months of life or during their second year.

An important new study from the University of California, Davis M.I.N.D. Institute published in March 2010 has raised a very significant challenge to our traditional assumptions. This study found that the high majority of children who developed autism did not show signs of the condition before age six months. However, most children started developing signs between six and twelve months, and new signs of autism continued to appear until they were three.

Although this study has come up with different results than prior studies, it is worth taking very seriously because it is a “prospective” study, meaning that researchers studied the children from birth, not knowing whether they would develop autism or not. Therefore, the data that they accumulated is all based on their observations. All prior studies have been retrospective, relying upon parent reports of their observations and recollections. Parents are generally not trained observers, are busy loving their children, not doing developmental exams, and will not remember every detail of the nature and timing of their child’s development as the years go on! So, this study is the first that meets a high scientific standard.

This study should change the way doctors treat autism and parents think of it. Pediatricians and others who screen children should start to pay close attention to such evaluations during the second half of the child’s first year of life and should also have a second look a year or so later. The study also showed that the first signs of autism are usually impairments in social relations, so this area (e.g., eye contact, appropriate smiling, imitation) should be carefully assessed.

Parents should be aware that if their child has been developing normally and then begins to show autism, this development does not mean that he or she has been exposed to some toxic substance such as a vaccine. Rather, this study suggests that there may have been subtle changes that would have been evident to a trained observer even during the time when the child appeared to be developing normally.

– Mental Health Matters! is written by the Lucy Daniels Center for Early Childhood and posted on the Carolina Parent Magazine's website, the Triangle's family resource - in print for over 21 years!  And online at www.carolinaparent.com.