Autism is diagnosed through a careful evaluation rather than a single medical test. A licensed psychologist decides whether your child meets the criteria in the DSM-5-TR, the manual clinicians use to diagnose autism. The psychologist looks at two areas. The first is social communication, such as eye contact, gestures, words, responding to their name and sharing play with others. The second is restricted or repetitive behaviors, such as repeated movements or words, a strong need for sameness, very focused interests, or unusual reactions to sounds, textures or other sensations. The psychologist combines what you share about your child’s development with their own observation, which can include the ADOS-2, a play-based assessment of communication, social interaction, play and repetitive behaviors. They also consider how much these affect daily life and whether something else, such as a developmental delay, better explains what they see.