Autism is a development disorder that causes impairments in social interaction and communication. People with autism have difficulty interacting with other people, speaking and understanding speech, making eye contact, and sometimes with basic life functions such as dressing and using the toilet. In 2013 the American Psychiatric Association redefined autism as autism spectrum disorders, or ASD, encompassing several conditions associated with communication difficulties and social problems. People with ASD are sometimes said to be “on the spectrum.” There is a range of disability associated with ASD, from children who are completely incapacitated to individuals with exceptional skills in certain areas—especially science and math—but with social and communication deficits.
The main symptom of autism is difficulty with social interaction, which can range from mild social impairment to complete inability to communicate. Babies with ASD often appear normal as infants, smiling and playing with their parents, but around the age of 18 months may stop making eye contact and smiling. They may be unresponsive to other people. They do not know how to play with others, a skill that normal children develop instinctively, and they cannot understand other peoples' feelings. They have a hard time making friends.
Some autistic children never speak and give no indication that they understand language. Others speak but in a monotone and on a narrow range of topics of interest to them. They may not understand or use gestures such as pointing. It is not always possible to tell if an autistic person understands language. Some people with ASD go for years without speaking, but then suddenly begin typing complete sentences, revealing that they have understood language and had complex thoughts for years.
Children with autism often engage in repetitive behaviors such as rocking, twirling, or head-banging. They may play by lining up objects or making stacks over and over again. Autistic people favor routines, doing the same things the same way every time. They can become obsessed with particular topics and think of nothing else for long periods of time.
As of 2008, about 11 children out of 1,000, or one in 88, were diagnosed with ASD. The number of diagnoses increased ten-fold between the 1970s and 2013. This is because of more public awareness and efforts to get diagnoses, but doctors believe that ASD is actually increasing as well. Boys are diagnosed four times more often than girls.
Until 2013, psychiatrists broke ASD conditions into several diagnoses that reflected the variation in symptoms among patients. The diagnosis formerly called Asperger syndrome was one of the more high-performing of disorders. People who received this diagnosis generally had difficulties with social interaction and nonverbal communication along with restricted interests but were able to speak and function fairly well; some were quite intelligent. Because it is difficult to distinguish among all the variations of autism, doctors decided to place them all within one diagnosis, ASD, and to address each case individually.
As of the early twenty-first century, the causes of ASD were unknown. The biggest contributing factor appears to be genetic. Autism is more common among siblings, especially identical twins, than in the general population. There are a number of other genetic conditions associated with autism, such as Rett syndrome and fragile X syndrome. Sometimes autism occurs along with intellectual disabilities.
Autism is slightly more common in children of parents older than 30 and in children of mothers who used certain prescription drugs during pregnancy, but there is not enough evidence to conclude that these factors caused ASD. People have suggested connections between vaccines and autism, but there is absolutely no scientific evidence to support these conclusions. The one small study thought to support a link has been refuted and retracted as unscientific, and the lead author of the paper on the study was discredited and stripped of his license to practice medicine.
There is no cure for autism. The best results have come from intensive one-on-one therapy starting in early childhood, but this is very expensive and not available to all patients. Some states will pay for this therapy for students, but others have fewer services. Some children improve with age. Others become more difficult to handle. Adolescents sometimes become violent and aggressive.
Parents of autistic children sometimes feel desperate and will try nearly anything to improve their children. Many parents put their children on restrictive diets, eliminating ingredients such as gluten—a protein found in wheat—or MSG (monosodium glutamate)—a common food additive. Some report success with these measures, though this can be hard to verify. There is a vast amount of information on autism on the Internet, some of it published by medical organizations and some of it simply the personal experiences of parents or people with autism. The United States National Institutes of Health (NIH) is studying ASD intensively.