Autism

Autism is a neurodevelopmental disorder characterized by impairment in emotional expression and recognition, difficulty with social relationships, delayed and/or abnormal language and communication, and preoccupation with repetitive, stereotyped behaviors or interests.

ALSO KNOWN AS: Autistic disorder, autism spectrum disorder, Asperger syndrome, pervasive developmental disorder

ANATOMY OR SYSTEM AFFECTED: Brain, psychic-emotional system

CAUSES: Unknown

SYMPTOMS: Difficulty with social relationships, language, and communication; preoccupation with repetitive or stereotyped behaviors and interests; general resistance to changes in routine

DURATION: Chronic

TREATMENTS: Behavior modification, social skills training, music therapy, speech/language therapy, occupational therapy

Causes and Symptoms

Autism is a lifelong neurodevelopmental disorder that is often diagnosed in early childhood, though mild presentations may not be diagnosed until later. According to the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders: DSM-5-TR (5th ed., text revisions, 2022), autism is diagnosed if there is evidence of persistent deficits in social communication and social interaction across multiple contexts, and restricted, repetitive patterns of behavior, interests, or activities. Autism also typically involves delays or abnormal functioning in imaginative and symbolic play in childhood. Signs and symptoms may be observed as young as twelve to eighteen months of age, but generally cannot be reliably diagnosed until two years or older.

In the DSM-5 (2013) and DSM-5-TR, autistic disorder is no longer a separate diagnosis from autism spectrum disorder (ASD), which aggregates the formerly separate diagnoses of autism, Asperger syndrome, childhood disintegrative disorder, and pervasive developmental disorder not otherwise specified (PDD-NOS). People with this diagnosis tend to demonstrate a wide range of behavioral, psychological, and physical symptoms at varying levels of severity. While the concept of autism spectrum disorder has been widely embraced, some advocacy groups and other sources continue to use the term “autism.”

In 2023 the US Centers for Disease Control and Prevention (CDC) reported that about one in thirty-six children has autism spectrum disorder, based on data collected in 2020, with boys being about four times more likely than girls to have these conditions. White children with autism have historically been more likely to be diagnosed than their Black and Latino counterparts, though by 2020, rates of diagnosis were higher among Black, Hispanic, and Asian and Pacific Islander children than White children. Girls and women, as well as people of color, have often been diagnosed at later ages than boys have been. Girls with autism are socialized differently than boys are and may be better at mimicking their neurotypical peers; thus, their social and communication challenges often are not as apparent as those of boys. Flawed diagnostic testing and gender-imbalanced research studies may also be contributing to missed diagnoses in girls and women. Meanwhile, racial bias, limited healthcare access, and differing cultural expectations are all thought to have contributed to underdiagnosis among children of color. Experts believe that general awareness of the prevalence of autism, as well as parental reporting, is significant for supporting efforts to provide services for those in need.

Some researchers have argued that autism has become increasingly prevalent, citing studies from the 1950s and 1960s that listed the incidence of autism at four to five cases per ten thousand children. However, it has also been suggested that the apparent rise in the incidence of autism simply reflects a rise in awareness of the disorder and an increase in the accuracy of the diagnostic criteria. Because of such debates, research in the twenty-first century is more specifically examining mechanisms by which children may develop autism, in addition to useful treatment methods.

The social interactions of individuals with autism spectrum disorder may be notably abnormal but can range widely from self-imposed social isolation to somewhat engaged but inappropriate social behavior. Typically, those with autism avoid eye contact. They also may demonstrate little, if any, facial expressiveness, and they generally do not produce social gesturing or body language. Individuals with autism often lack empathy; they may not smile in response to other people’s expressions of happiness or attempt to comfort others in distress. While most children with autism develop attachments to their parents and other caregivers, there is a marked aloofness and lack of social reciprocity in their interactions even with close others. In adults with autism, close friendships and romantic attachments are not common.

It is often said that individuals with autism do not relate to other people as people, but rather treat people more like objects. A classic example of this is a child with autism leading an adult by the hand and then placing the adult’s hand on a door, rather than verbally or gesturally requesting that the door be opened.

Language development in children with autism spectrum disorder is often delayed, and between 25 and 30 percent never acquire spoken language, despite having normal hearing abilities. Those individuals with autism who do develop language often show evidence of low-level linguistic disorders such as echolalia, persistent use of neologisms, pronoun reversals, and other grammatical anomalies. The subset of individuals with autism who develop fluent speech typically demonstrate poor conversational skills, related to the general lack of social reciprocity seen in autism. Their speech is often delivered in a monotone, is repetitive, and focuses mainly on their own concerns. They may show little awareness of the perspectives or interests of their listeners.

Individuals with autism may also show deficits in receptive communication. There is reduced attention to human voices in general, poor understanding of nonverbal language—including gesture and vocal intonation—and difficulties with nonliteral language such as metaphor and irony.

Many individuals with autism demonstrate a preoccupation with restricted and repetitive behaviors (known as stereotypies or stimming), interests, and activities. This focus on repetition can take a range of forms, from performance of stereotypies to compulsive insistence on daily routines to an intense focus upon specific, narrow topics of interest. Common stereotypies seen in autistic individuals are hand flapping, head banging, or more complex whole-body movements.

Autistic children sometimes engage in self-injurious behavior patterns, such as self-biting or head banging, and/or self-soothing behaviors, such as rocking, self-stroking, or hair twirling. Some children with autism also develop pica, eating such things as paper, paperclips, or dirt.

More complex ritualistic behavior patterns might include compulsive handwashing, counting, or arrangement of possessions. This aspect of autism can also include intense preoccupation with highly restricted topics, such as weather patterns, buttons, or television schedules.

Another defining characteristic included in the diagnostic criteria for autism spectrum disorder is a lack of imaginative or pretend play in childhood. This symptom may be related to the general literalness seen in autistic communication. The play of children with autism tends to be solitary and to involve the repetitive manipulation of objects. The one-sidedness of autistic children’s play and their generally impaired social interactions typically result in failure to develop peer relationships appropriate to their developmental level. Children with autism are therefore often cut off from their peer groups, which can cause feelings of loneliness and depression, especially as they approach adolescence.

Up to three-quarters of people with autism are also intellectually disabled, with an intelligence quotient (IQ) below 70. The mental profiles of autistic people can be uneven, however, with particularly low verbal IQ scores but normal or near-normal scores on measures of mathematical and spatial IQ. Indeed, average or even strong academic performance is a common reason for delayed or missed autism diagnoses.

As of the early twenty-first century, there is no known cause of autism. Risk factors include genetic relatedness to others with ASD, preterm birth, low birth weight, air pollution exposure, maternal stress, and comorbid disorders such as attention deficit hyperactivity disorder (ADHD) and obsessive-compulsive disorder (OCD). Coexisting psychiatric conditions, such as anxiety and depression, can also at times lead to missed diagnoses. People with autism can also be misdiagnosed with ADHD, OCD, social anxiety disorder, separation anxiety disorder, or learning disabilities.

In the 1990s, scientists investigated the claim, initially made by parents and bolstered by apparently rising rates of autism, that the measles, mumps, and rubella (MMR) vaccine, typically given around age eighteen months, caused autism in some cases. A number of thorough epidemiological studies found no evidence for a link between the MMR vaccine and autism, although some researchers suggested that the vaccine could exacerbate already-present autistic symptoms in toddlers. Although the antivaccination movement has continued to circulate conspiracy theories regarding autism, health experts agree that these fears are unfounded and that not vaccinating children poses a risk for both those children and society as a whole.

Treatment and Therapy

There is no cure for autism spectrum disorder, nor is there one single treatment. Because children with autism can display such a wide range of symptoms, the range of available treatments is also wide. Physicians, psychologists, and other health professionals focus on alleviating the symptoms that are the most disruptive to a particular individual with autism. Available treatments include behavior modification, social skills training, speech therapy, language therapy, occupational therapy, play therapy, music therapy, dietary interventions or other natural treatments, and medication, among others. Often a combination of these types of treatments will be used to address the therapeutic needs of an autistic individual.

One of the most successful treatments for autism has been intensive behavior modification therapy. In his book The Autistic Child: Language Development through Behavior Modification (1977), O. Ivar Lovaas describes a program of intensive one-on-one behavior modification therapy that can be highly effective in alleviating disturbing symptoms and in engendering positive social behaviors in autistic children. Lovaas’s technique is controversial because it involves both rewards for appropriate behaviors, such as making eye contact or maintaining conversation, as well as punishments for inappropriate behaviors, such as self-damaging acts, stereotypies, or pica.

In a well-publicized legal case in the 1990s, the state of Massachusetts banned the use of punishment in a school for autistic children. As a result, the children’s levels of self-injurious behavior increased, to the extent that the parents petitioned for punishment to be reinstated in the school’s behavior modification program. While the utility of punishment is generally acknowledged, many behavior modification therapists now suggest that the positive reinforcement of rewarding appropriate behavior is effective enough that punishment for inappropriate behavior is not necessary. Despite variations in philosophy and technique, behavior modification aimed at increasing social responsiveness and decreasing inappropriate behaviors is generally an essential component of therapy for autistic children.

Social skills training is used to encourage individuals with autism spectrum disorder to adhere to the implicit rules of conversation and social interaction (for example, looking at people’s faces when speaking to them). Occupational therapy focuses on teaching skills that allow individuals with autism to participate in daily life: crossing a street, preparing simple meals, making purchases, and answering the telephone. Play therapy involves entering the world of the autistic individual—in the case of children, spending “floor time” with them to break through their aloofness. Music therapy has been used to draw emotional responses from children with autism, with varied levels of success. Dietary interventions have also been found to alleviate some of the symptoms of autism in certain cases.

No drug is specifically prescribed for autism spectrum disorder; however, various medications are sometimes used to treat the symptoms of autism. Stimulant drugs may be used to treat the inattentiveness of autistic children who are particularly isolated and unresponsive. Tranquilizing drugs may be prescribed to manage obsessive-compulsive behaviors that are disruptive to normal functioning. Antidepressants are also sometimes prescribed for autistic children to heighten emotional responsiveness and/or to stabilize mood. As many as one-third of children with autism develop seizures, often in adolescence, that are similar to epileptic seizures. These seizures are usually treated with medication.

Outcomes for individuals with autism spectrum disorder depend on their symptoms. Autistic individuals with mild impairments can live at home, participate in family and social life, go to mainstream schools, and eventually take on appropriate paid work. In fact, some highly repetitive occupations, such as shelving books in a library or entering computer data, may fit extremely well with the desires and talents of individuals with autism. Some people with autism spectrum disorder are very high-achieving. Those with more profound autistic symptoms or significant intellectual disability may go to special schools, participate in remedial programs, or live in special residential facilities. Whatever the setting, individuals with autism respond most positively to a highly structured environment in which the other people are understanding and tolerant of their social and communicative differences.

Parents, siblings, and friends of individuals with autism spectrum disorder may also benefit from therapy. Life with an autistic person can be rewarding, especially when progress is made, but it can also be frustrating and depressing. Often the parents, siblings, and friends of children with autism, as well as professionals working with such children, feel rejected by the autistic tendency to avoid close social contact. Most professionals suggest that anyone who spends extended periods of time with an individual with autism will benefit from some form of training and/or emotional support.

The COVID-19 pandemic that began in 2020 created complications for those living with autism spectrum disorder. In 2021, the National Institute of Mental Health found that the immense lifestyle changes resulting from the COVID-19 pandemic led to drastic changes in routines that were particularly disruptive for many on the autism spectrum. Changes in social norms, including physical distancing, quarantining, and the restriction of activities, contributed to a general decline in mental health for both individuals on the autism spectrum and their families. However, a 2020 Child and Adolescent Mental Health study found that despite the long-term developmental implications, many children with high-functioning autism spectrum disorder preferred remote learning due to reduced anxiety and depression in virtual social situations as compared to physical ones.

Perspective and Prospects

Though it is likely to be an old syndrome, autism was first described in the 1940s. Leo Kanner in the United States and Hans Asperger in Austria independently published papers describing children with severe social and communicative impairments. Both Kanner and Asperger used the term “autism” (meaning “alone”) to describe the syndromes they had identified. Kanner described children who had impoverished social relationships from early in life, employed deviant language, and were subject to behavioral stereotypies. Asperger’s description identified children with normal IQs and normal language development who suffered from social and some types of communicative impairments.

In his original report, Kanner observed that the parent-child relationships in cases of children with autism appeared to be somewhat unusual. This suggestion fit with the tenor of the times, in which psychology and psychiatry were dominated by Freudian theories. Thus early explanations of autism, now discredited, suggested that children developed the syndrome as a result of cold, abusive, or confusing home environments (references were made to “refrigerator mothers”), and early treatments of autism focused on improving parent-child relationships or removing children with autism from their home environments.

In the twenty-first century, work on autism has focused on the physiological and cognitive aspects of the disorder. Brain studies utilizing functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) scanning have uncovered several differences in the brains of individuals with autism, including larger-than-normal brains, and atypical functioning in the areas thought to be responsible for social interactions. In particular, the structure and functioning of the mirror neuron system, hypothesized to be the structural substrate for empathy, have been shown to be abnormal in individuals with autism. Cognitive studies of autism have suggested that the perceptual and reasoning proclivities of individuals with autism are abnormal. One hypothesis is that autistic individuals’ minds are characterized by “weak central coherence,” such that they prefer to focus on details and parts rather than on global wholes, leading to the tendency to focus on concrete minutia while avoiding complex and dynamic human interaction. Another hypothesis is that individuals with autism lack a “theory of mind,” which results in an inability to consider others’ emotions, perspectives, desires, and thoughts.

As research into and awareness of autism has grown, so have efforts to normalize autism. Beginning in the 1990s, some advocates have maintained that autism, ADHD, learning disabilities, and other neurological conditions are natural variations in brain function, and therefore individuals with those conditions are neurodiverse or neurodivergent, and object to the idea that those individuals need to be “fixed” in some way. This neurodiversity movement has proven divisive, however.

Bibliography

American Psychiatric Association. “DSM-5 Proposed Criteria for Autism Spectrum Disorder Designed to Provide More Accurate Diagnosis and Treatment.” Release No. 12–03, APA, 2012.

American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders: DSM-5-TR. American Psychiatric Publishing, 2022.

Autism Speaks. Autism Speaks, 2024, www.autismspeaks.org/. Accessed 16 July 2024.

“Autism Spectrum Disorder.” MedlinePlus, US National Library of Medicine, 7 Aug. 2020, medlineplus.gov/autismspectrumdisorder.html. Accessed 28 Mar. 2024.

“Data and Statistics on Autism Spectrum Disorder.” Centers for Disease Control and Prevention. 25 Jan. 2024, www.cdc.gov/autism/data-research/. Accessed 16 July 2024.

Frith, Uta. Autism: Explaining the Enigma. 2nd ed., Blackwell, 2006.

Ghorayshi, Azeen. “More Girls Are Being Diagnosed with Autism.” The New York Times, 14 Apr. 2023, www.nytimes.com/2023/04/10/science/autism-rate-girls.html. Accessed 16 July 2024.

Gordon, Joshua. “Addressing the Needs of the Autism Community during COVID-19.” National Institute of Mental Health, 27 April 2021, www.nimh.nih.gov/about/director/messages/2021/addressing-the-needs-of-the-autism-community-during-covid-19. Accessed 16 July 2024.

Greenspan, Stanley, and Serena Wieder. Engaging Autism: Using the Floortime Approach to Help Children Relate, Communicate, and Think. Da Capo, 2006.

Happe, Francesca. Autism: An Introduction to Psychological Theory. Psychology, 2002.

Miller, Caroline. “What Is Neurodiversity?” Child Mind Institute, 8 Mar. 2024, childmind.org/article/what-is-neurodiversity/. Accessed 16 July 2024.

Nedelman, Michael. “Autism Prevalence Now 1 in 40 US kids, Study Estimates.” CNN, 26 Nov. 2018, www.cnn.com/2018/11/26/health/autism-prevalence-study/index.html. Accessed 16 July 2024.

Reicher, Debra. “Debate: Remote Learning during COVID-19 for Children with High Functioning Autism Spectrum Disorder.” Child and Adolescent Mental Health, vol. 24, no. 4, 2020, pp. 263–264, doi:10.1111/camh.12425. Accessed 16 July 2024.

Ries, Julia. “Autism: Rates in Children Reach New Highs, Experts Explain Why.” Healthline, 27 Mar. 2023, www.healthline.com/health-news/autism-rates-in-children-reach-new-highs-experts-explain-why. Accessed 16 July 2024.

Rudy, Lisa Jo. “5 Reasons Why an Autism Diagnosis Is Missed.” Verywell Health, 9 Feb. 2024, www.verywellhealth.com/high-functioning-autism-260305#citation-10. Accessed 16 July 2024.

Silberman, Steve. Neurotribes: The Legacy of Autism and the Future of Neurodiversity. Avery, 2015.

Volkmar, Fred R., et al. Handbook of Autism and Pervasive Developmental Disorders. Wiley, 2014.

“What Are the DSM-5 Diagnostic Criteria for Autism?” Autism Speaks. www.autismspeaks.org/autism-diagnosis-criteria-dsm-5. Accessed 16 July 2024.

Wickelgren, Ingrid. “Is a Diagnostic Test to Blame for Why We Know So Little about Autism in Girls?” Scientific American, 22 Nov. 2022, www.scientificamerican.com/article/is-a-diagnostic-test-to-blame-for-why-we-know-so-little-about-autism-in-girls/. Accessed 16 July 2024.

Wilkinson, Lee A., editor. Autism Spectrum Disorder in Children and Adolescents: Evidence-Based Assessment and Intervention in Schools. American Psychological Association, 2014.

Wiseman, Nancy D., and Robert L. Rich. The First Year: Autism Spectrum Disorders—An Essential Guide for the Newly Diagnosed Child. Da Capo, 2009.