Autism: Early Detection and Intervention

Learn about early detection and intervention for autism spectrum disorders with research from Director of the Kennedy Krieger Institute Center for Autism and Related Disorders, Rebecca Landa, Ph.D. Be sure to review Dr. Landa's chart of observable autism characteristics by age.

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Autism:  Early Detection and Intervention Fact Sheet

Rebecca Landa, Ph.D.

Director, Kennedy Krieger Institute Center for Autism and Related Disorders

Early Detection:

  • Signs of developmental disruption may be observable in some children with Autism Spectrum Disorders (ASDs) before their first birthday, while in other children, signs may not clearly appear until the second or third year of life.
  • In most cases, the early signs of autism involve decreased frequency of expected behaviors (such as smiling at others), and decreased variety of behaviors (words, gestures, actions in play).
  • The first warning signs may differ from one child to another, but there is always difficulty showing a social connection to others, and usually some delayed aspect of communication (e.g.: babbling, gesture, first words, word combinations).
  • On average, parents express their first concerns about their child with autism between 15 and 24 months of age.
  • Loss of social and/or language skills, known as regression, occurs in around one-third of children with autism, usually sometime around 15 - 21 months of age.  Loss of skills may be very gradual in some children, but are often regained.  In some children, skills may plateau.


  • About half of children with ASDs could be diagnosed around their first birthday by professionals who have extensive experience with very young children and autism.  On average, nationally, children are diagnosed with autism at three years of age, while children with high intellectual functioning and ASD tend to be diagnosed later (often around six years of age).
  • On average, nationally, there is a 13-month gap between the time a child is first evaluated due to concerns about development and the subsequent time of diagnosis of ASD.
  • In children younger than 30 months, the diagnosis of autism is least stable.  Some very young children, especially those with higher developmental levels, may improve so much by the third birthday that a diagnosis of ASD is no longer appropriate.  Many of these children do have residual language and/or social delays at three years of age.

Article written by Rebecca Landa
Director of the Kennedy Krieger Institute Center for Autism and Related Disorders