The first signs of autism spectrum disorder typically present in early childhood—often in a child’s first year—and the condition will continue to affect them throughout the course of their lives. While ASD is described as a spectrum specifically because of the variety of ways it can present among individuals, there are some consistent trends among different age groups of people with autism spectrum disorder. Here are some of the most notable ways symptoms of autism vary between age groups.
Autism symptoms in infants
The first two years of a child’s life are the time during which symptoms of autism spectrum disorder are most likely to first present. Here are some common signs to look out for, by age:
By six months: Limited expressions of joy, like big smiles and other engaging behaviors with caregivers and limited or no eye contact
By nine months: Little or no back-and-forth sharing of sounds and limited smiles and other facial expressions
By 12 months: Little or no attempts at verbalization (babbling, intentional noises), limited gestures such as pointing, showing, reaching or waving, and lack of response to name
By 16 months: Very few, or in some cases no words
Autism symptoms in toddlers
In toddlers, symptoms of autism spectrum disorder include:
Regression of previously mastered skills—particularly language, communication, and social skills.
Lack of eye contact
Lack of response to their name or the sound of familiar voices
Aversion to cuddling and physical affection
Failure to imitate the movements and facial expressions of caregivers
Lack of interest in playing with others
Failure to notice when others are hurt or experience discomfort
Echolalia—the meaningless repetition of words overheard.
Use of other’s body as a tool
No use or understanding of gestures
Limited range of facial expression
Lack of emotional expression
Lack of interest in age appropriate play with toys
Autism symptoms in young children
Poor social interaction
Lack of interest in other children
Lack of seeking to share own enjoyment
Failure to develop peer relations
Failure to join in activities of others
Failure to direct adult’s attention to own activity
Failure to seek or offer comfort
Dislike of social touch
Lack of social responsiveness
Tendency to ignore people
Lack of social play
Tendency to “be in their own world”
Preference to be alone
Indifference to others
Failure to differentiate between people
Autism symptoms in older children
By later in childhood and into their early teens, people with autism spectrum disorders may exhibit the following symptoms and behaviors:
Trouble taking turns in conversations—either in the form of dominating conversations or preferring only to listen and not speak
Obsessive talk a lot about a particular topic
Unusual speech pattern or tone
Difficulty following instructions with more than one or two steps
Trouble reading nonverbal cues, like body language or tone of voice
Inappropriate use of eye contact
Limited use of gestures and facial expressions
Difficulty making or maintaining friendships
Development of rigid rules that they require others to follow
Difficulty connecting with peers (oftentimes, older children and teens with autism will gravitate toward younger children or adults, rather that people their own age)
Poor understanding of personal space and boundaries
Unusual interests or obsessions
Development of compulsive behaviors
Difficulty adapting to changes
Sensitivity to sensory experiences
Struggles with anxiety and depression
Autism symptoms in teens
While they may develop at any point, these common symptoms of autism spectrum disorder are often particularly pronounced or problematic during the teenage years:
Hyperactivity
Impulsivity
Short attention span
Aggression
Self injury
Meltdowns
Unusual eating and sleeping habits
Unusual mood or emotional reactions
Have unusual sleeping habits
There is some evidence to suggest that symptoms of autism spectrum disorder may improve for some people during their teens. One study, which followed about 300 children from age 2 to 21, found that about ten percent of children improve dramatically by their mid-teens.
The same study found that another 80 percent of the children who were tracked had symptoms that stayed very consistent over time—suggesting that, for most people with ASD, the teenage years will be a turning point in the condition, during which time symptoms are likely to stabilize considerably or even improve.
Autism symptoms in adults
Autism spectrum disorder continues to affect people into adulthood. Some common symptoms experienced by adults with autism spectrum disorder include:
Difficulty understanding what others are thinking or feeling
Anxiety in and about social situations
Difficulty forming friendships
A preference to spend time alone, rather than with others
Unintentionally appearing blunt, rude or not interested in others
Difficulty expressing feelings and emotions
Tendency to take things literally and not understand sarcasm and jokes
Anxiety when routines are disrupted