Updated: Jul 12, 2019
In a study at University of California, San Diego, 1,269 children between 12 and 36 months were screened for autism by trained psychologists.
According to the findings, 50% of children were able to be diagnosed with autism at 12-13 months, 79% by 14 months, and 83% by 16 months.
Eighty-four percent of children who were initially diagnosed, retained their diagnosis at 3-4 years. The remaining 16% presented with milder delays at a later age. After delays were detected, all of the children in the study were referred to begin therapy, therefore, improvements in severity may have been attributed to early treatment.
The study’s first author, Dr. Karen Pierce, co-director of the UC San Diego Autism Center of Excellence and professor of neurosciences says that the findings suggest that an autism diagnosis becomes stable starting at 14 months.
There have been studies that have shown that autism can be detected in children between 12 and 18 months based on parent report. However, the average age of diagnosis is between 3 and 4 years. Brain development is rapidly accelerated between birth and three to four years, and because of late detection of autism, there are missed opportunities for children to receive therapy during this critical time in their lives.
What does this study mean for the future of autism assessment and treatment?
Early identification leads to improved outcomes. The brain’s synaptic density, or connections between neurons, doubles in the first two years of life. If children are able to be diagnosed with autism under the age of 2, this means that families will begin therapy at an earlier age, leading to better therapeutic outcomes.
If you want to receive a FREE download, Earliest Signs of Autism, a handout to use in therapy sessions and with parents, click here.
Pierce K, Gazestani V, Bacon E, et al. (2019). "Evaluation of the Diagnostic Stability of the Early Autism Spectrum Disorder Phenotype in the General Population Starting at 12 Months." JAMA Pediatrics, 173(6):578-587. Read the full article on JAMA.
Jessie Ginsburg is a speech-language pathologist, autism expert, and the owner of Pediatric Therapy Playhouse, a multidisciplinary clinic in Los Angeles.