ADHD & Autism Screening
for Children

Catching a developmental difference early makes a real difference, because the first years are when support helps most. This page explains when ADHD and autism can be identified, why autism screening is recommended for every child, and how to arrange screening and assessment for your child.

When can ADHD and autism be diagnosed?

Autism spectrum disorder can often be identified in the first two to three years of life. Signs may appear before a child's first birthday, and in many children autism can be reliably recognised by around 18 to 24 months, though it is sometimes identified later. ADHD (attention-deficit/hyperactivity disorder) is usually recognised later, most often between the ages of 6 and 12, when the demands of school make attention and activity difficulties clearer, although it can appear earlier or be identified in teenagers and adults. For both, earlier recognition means earlier support, which is why screening matters.

Why every child should be screened for autism at 18 and 24 months

Autism screening is not only for children with obvious concerns. Paediatric guidelines, including those from the American Academy of Pediatrics, recommend that every child be screened specifically for autism at 18 months and again at 24 months, as part of routine developmental checks. Early signs can be subtle and easy to miss, and picking them up early opens the door to support at the stage when it helps most. Screening at both ages matters because some signs only become clear a little later.

Autism screening and diagnosis with Dr. Chitrakshi Tewari

Dr. Chitrakshi Tewari offers a dedicated autism screening consultation for children. It is a focused session, separate from a general paediatric consultation, using validated screening tools such as the M-CHAT-R/F for toddlers, alongside a detailed developmental history and careful observation of how your child communicates, plays and interacts.

What the screening includes:

Screening is the first step, and it is not itself a formal diagnosis. If it indicates a closer look is needed, the formal autism diagnostic assessment gives you a clear answer, and Dr. Tewari explains what it means in plain language and guides you on early intervention and support.

ADHD screening and assessment

ADHD is diagnosed clinically, not with a single test. It involves a careful history and standardised rating scales completed by parents and teachers, such as the Vanderbilt or Conners scales, and ruling out other explanations like sleep problems, hearing difficulties or anxiety.

You can also read Dr. Tewari's parent guide to ADHD in children.

What happens if screening flags a concern

A screening that raises a concern is not a diagnosis, and it is not a reason to panic. It simply means a closer look is worthwhile. Dr. Tewari will guide you towards a full diagnostic evaluation and, where helpful, early intervention such as speech therapy, occupational therapy or structured developmental support. Starting early, even before a formal diagnosis, is one of the most powerful things you can do for your child.

Medically reviewed by Dr. Chitrakshi Tewari

MD Paediatrics (LHMC & Kalawati Saran Children's Hospital, Delhi) · All India Rank 1, AIIMS Delhi · Gold Medalist · Online consultations across India