Children with autism generally have problems in three crucial areas of development — social interaction, language and behavior. But because autism symptoms and severity vary greatly, two children with the same diagnosis may act quite differently and have strikingly different skills. In most cases, though, children with severe autism have marked impairments or a complete inability to communicate or interact with other people.

Some children show signs of autism in early infancy. Other children may develop normally for the first few months or years of life, but then suddenly become withdrawn or aggressive or lose language skills they've already acquired.

Though each child with autism is likely to have a unique pattern of behavior, these are some common autism symptoms:

Social skills

  • Fails to respond to his or her name
  • Has poor eye contact
  • Appears not to hear you at times
  • Resists cuddling and holding
  • Appears unaware of others' feelings
  • Seems to prefer playing alone — retreats into his or her own world
  • Doesn't ask for help or request things

Language

  • Doesn't speak or has delayed speech
  • Loses previously acquired ability to say words or sentences
  • Doesn't make eye contact when making requests
  • Speaks with an abnormal tone or rhythm — may use a singsong voice or robot-like speech
  • Can't start a conversation or keep one going
  • May repeat words or phrases verbatim, but doesn't understand how to use them
  • Doesn't appear to understand simple questions or directions

Behavior

  • Performs repetitive movements, such as rocking, spinning or hand-flapping
  • Develops specific routines or rituals and becomes disturbed at the slightest change
  • Moves constantly
  • May be fascinated by details of an object, such as the spinning wheels of a toy car, but doesn't understand the "big picture" of the subject
  • May be unusually sensitive to light, sound and touch, and yet oblivious to pain
  • Does not engage in imitative or make-believe play
  • May have odd food preferences, such as eating only a few foods, or craving items that are not food, such as chalk or dirt
  • May perform activities that could cause self-harm, such as headbanging

Young children with autism also have a hard time sharing experiences with others. When read to, for example, they're unlikely to point at pictures in the book. This early-developing social skill is crucial to later language and social development.

As they mature, some children with autism become more engaged with others and show fewer disturbances in behavior. Some, usually those with the least severe problems, eventually may lead normal or near-normal lives. Others, however, continue to have difficulty with language or social skills, and the teen years can bring worse behavioral problems.

Most children with autism are slow to gain new knowledge or skills, and some have signs of lower than normal intelligence. Other children with autism have normal to high intelligence. These children learn quickly, yet have trouble communicating, applying what they know in everyday life and adjusting in social situations. A small number of children with autism are savants — they have exceptional skills in a specific area, such as art, math or music.

When to see a doctor

Babies develop at their own pace, and many don't follow exact timelines found in some parenting books. But children with autism usually show some signs of delayed development within the first year. If you suspect that your child may have autism, discuss your concerns with your doctor. The symptoms associated with autism can also be associated with other developmental disorders.The earlier that treatment begins, the more effective it will be.

Your doctor may recommend more developmental tests if your child:

  • Doesn't respond with a smile or happy expression by 6 months
  • Doesn't mimic sounds or facial expressions by 9 months
  • Doesn't babble or coo by 12 months
  • Doesn't gesture — such as point or wave — by 12 months
  • Doesn't say single words by 16 months
  • Doesn't say two-word phrases by 24 months
  • Loses previously acquired language or social skills at any age
Oct. 06, 2012