But the U.S. Centers for Disease Control says that it’s possible to get a reliable autism diagnosis as early as age 2. And many parents notice early signs before their child’s first birthday and realize something is different by the time their child is 18 months old.
The earlier a child with autism begins treatment, the better the outcome. If you notice any of these signs or have concerns about your child’s development, talk with his doctor.
Signs of autism in babies younger than 12 months old
At this age, picking up on signs of autism involves paying attention to whether your child is meeting developmental milestones. Here are some things to watch for:
- Doesn’t show interest in faces.
- Doesn’t make eye contact, doesn’t smile, and may even seem to look right through you.
- Doesn’t always react to sounds. Doesn’t respond to his name, doesn’t turn around to see where a sound is coming from, or doesn’t appear startled when he hears a loud noise. In other situations, his hearing may seem fine.
- Doesn’t like being cuddled or touched.
- Doesn’t show interest in typical baby games, like peekaboo.
- Doesn’t babble or show other early signs of talking.
- Doesn’t use gestures, like reaching for you when she wants to be held.
Read more about milestones for ages 1 to 6 months and 7 to 12 months.
Signs of autism in toddlers 12 to 24 months old
- Doesn’t use gestures. Doesn’t shake his head yes or no. Doesn’t wave goodbye or point to things he wants.
- Doesn’t point out objects to show interest in the world around her. By 14 to 16 months, most kids point to get your attention to share something they’re interested in, such as a puppy or new toy.
- Doesn’t use single words by 16 months or two-word phrases by 24 months.
- Loses verbal or social skills. Used to babble or speak a few words, or showed interest in people, but now he doesn’t.
- Withdraws. Seems to tune people out and be in her own world.
- Walks on his toes or doesn’t walk at all.
Read more about milestones for ages 13 to 24 months.
Signs of autism in children 2 years old and up
- Has a language delay. May struggle to express her needs. Some children with autism don’t talk at all, while others develop language but have trouble participating in a conversation.
- Has unusual speaking patterns. Might speak haltingly, in a high-pitched voice or a flat tone. Might use single words instead of sentences or repeat a word or phrase over and over. Might repeat a question rather than answer it.
- Doesn’t seem to understand what people are saying to her. May not respond to her name or may be unable to follow directions. May laugh, cry, or scream inappropriately.
- Narrowly focuses on a single object, one thing about an object (like a wheel on a toy car), or one topic at a time.
- Engages in limited imitation. Rarely mimics what you do and doesn’t engage in pretend play.
- Seems content to play alone. Appears to have little interest in other children and usually doesn’t share or take turns.
- Displays rigid behavior. May be very attached to routines and have difficulty with transitions. For example: A change in the usual route home from daycare can throw her into despair or result in a tantrum. She’s very particular about what she will and won’t eat. Or she wants to follow strict rituals at snacks and meals.
- Plays with objects or toys in unusual ways. For example: He spends a lot of time lining things up or putting them in a certain order. He enjoys repetitively opening and closing a door. Or he becomes preoccupied with repeatedly pushing a button on a toy or spinning the wheels of a toy car.
- Engages in self-injury, such as biting or hitting herself.
- Exhibits repetitive actions, such as flapping his arms or hands.
- Is overly sensitive to various kinds of stimulation. May resist touch, get agitated by noise, be extremely sensitive to smells, or refuse to eat many foods. He may want to wear only clothes without tags or made of a certain material.
- May overreact to some types of pain and underreact to others. For example, she may cover her ears to block loud noises but not notice when she skins her knee.
- May be fearful when it’s unnecessary or fearless when there’s reason to be afraid. For example, he may be afraid of a harmless object, like a balloon, but not frightened of heights.
- Has sleep disturbances. Many children with autism have trouble falling asleep and wake up frequently in the night or are very early risers.
- Exhibits behavior problems. May be resistant, uncooperative, or overly active. May be hyperactive, impulsive, or aggressive.