This topic:  print  email  download as pdf      

What is this topic about?

This topic gives very basic information about autism spectrum disorder (ASD). It is meant for people who are first learning about ASD. This topic focuses on ASD in adults.

Back to Top

What are the diagnostic criteria for ASD and what might they look like in adults?

Autism spectrum disorder (ASD) is a condition described in the Diagnostic and Statistical Manual of Mental Disorders: DSM 5.1 It is diagnosed based on observation by a diagnostician or team of diagnosticians (e.g. neuropsychologist, psychologist, psychiatrist, licensed clinical social worker, etc.). If you're interested in learning more about diagnosis, see the topic Adult ASD Diagnosis.

The table below lists the current diagnostic criteria for ASD, along with examples of what they may look like in adults.2

DSM5 Criteria for ASD Examples of how criteria may manifest in adults
A. Persistent deficits in social communication and social interaction across multiple contexts. (Diagnosis requires person meets all three criteria.) 1. Deficits in social-emotional reciprocity Difficulty initiating or sustaining back and forth conversation; tendency to monologue without attending to listener cues; unusual response to greetings or other social conventions.
2. Deficits in nonverbal communicative behaviors used for social interaction Lack of eye contact; difficulty understanding non-verbal communication; unusual tone of voice or body language.
3. Deficits in developing, maintaining, and understanding relationships Challenges adapting behavior to match different social settings such as when interacting with family, friends, authority figures, or strangers; difficulty developing or sustaining friendships; greater than usual need for time alone.
B. Restricted, repetitive patterns of behavior, interests, or activities. (Diagnosis requires person meets at least two of four criteria.) 1. Stereotyped or repetitive motor movements, use of objects, or speech Repetitive movements or "stimming" (e.g., rocking, flapping, pacing, or spinning for enjoyment or as a coping mechanism); arranging objects in a very precise manner; echolalia; continuously repeating sounds, words, or phrases.
2. Insistence on sameness, inflexible adherence to routines, or ritualized patterns of verbal or nonverbal behavior Greater than expected degree of distress with changes in routines or expectations; difficulty transitioning between activities; need to do the same thing in the same way each time; greater than usual reliance on rituals for accomplishing daily tasks.
3. Highly restricted, fixated interests that are abnormal in intensity or focus Intense special interests (e.g., looking at spinning objects for hours, learning the detailed schedules of an entire public transportation system, or becoming an expert in seventeenth century art) while having significant difficulty attending to topics outside of one's areas of special interest.
4. Hyper- or hyporeactivity to sensory input or unusual interest in sensory aspects of the environment Being hyper- or hypo-sensitive to sounds, lights, smells, or textures; having an abnormally high or low pain threshold; difficulty processing more than one sense at a time (e.g., not being able to understand spoken language while looking at someone's face); tendency to become confused or overwhelmed by sensory stimuli; challenges with body awareness or separating different types of sensations.
C. Symptoms must be present in the early developmental period (but may not become fully manifest until social demands exceed limited capacities, or may be masked by learned strategies in later life) Though characteristics should have been present throughout one's lifetime, a change in circumstances can disrupt coping strategies and make characteristics more pronounced; alternatively, environmental facilitators, supports, and coping strategies may make characteristics less noticeable.
D. Symptoms cause clinically significant impairment in social, occupational, or other important areas of current functioning. Characteristics lead to difficulty obtaining or sustaining employment, doing basic or instrumental activities of daily living, maintaining social life, or integrating with community. For example, there may be significant mismatch between educational attainment and occupational history.
E. These disturbances are not better explained by intellectual disability or global developmental delay. Intellectual disability and autism spectrum disorder frequently co-occur; to make comorbid diagnoses of autism spectrum disorder and intellectual disability, social communication should be below that expected for general developmental level. N/A

Though the DSM-5 conceptualizes ASD primarily as a social-communication disorder, there is a growing literature supporting the hypothesis that ASD is primarily characterized by differences in information processing.3 See, for example, the intense world theory of ASD.

Adults on the autism spectrum may display autistic traits very differently from children. Most people, whether or not they are on the autism spectrum, mature and behave differently as they get older. As such, adults on the spectrum may not fit society's images of autistic children. Also, adults often find coping strategies that help them function in the world, but that may make autistic traits harder to recognize.

Among adults who meet the diagnostic criteria for ASD, autistic traits may look very different. While anyone on the spectrum would be expected to have challenges with social communication, these challenges can show up in many different ways. For example, a person may not be able to speak, may misunderstand facial expressions and body language, or may take language too literally. A person may have difficulty starting a conversation, may need more time alone than most people, or may feel uncomfortable socializing with others without a planned activity.

Likewise, anyone on the spectrum would be expected to have restricted or repetitive patterns of behaviors, interests, or activities, but that can be different for each person. For example, a person may look at spinning objects for hours, learn the detailed schedules of an entire public transportation system, or be an expert in seventeenth century art. Many people on the spectrum appreciate structure and can find routines very helpful in understanding or coping with the world. For example, they may always need to take the same route to get somewhere or may use a very complex organizational system to function at work or remember to eat. Unplanned events or changes in routines may cause anxiety for people on the autism spectrum.

People on the autism spectrum may experience sensory input differently from other people. For example, a person might have very sensitive hearing whereas another might have an extremely high pain threshold. Often people may have a very hard time coping with certain sensations, such as fluorescent lights, loud sounds, light touch, or particular textures or smells. They may not be able to process more than one sense at a time; for example, they may not be able to understand spoken language while looking at someone's face. They may also get overwhelmed when there are a lot of sensory stimuli happening all at once.

Some people on the spectrum may have difficulty with motor skills. Examples may include difficulty with handwriting, catching a ball, or planning out complex, multi-step actions like learning a dance sequence.

Autistic traits can potentially be strengths or challenges, or sometimes both. Not all people on the autism spectrum have stereotypical positive traits such as being good at memorizing things or using computers. Similarly, people on the autism spectrum do not all shy away from social interactions, and many can maintain strong friendships or relationships.

Back to Top

What's the difference between autism, Asperger's, PDD-NOS, and ASD?

The Diagnostic and Statistical Manual (DSM) is the book that defines these terms. Different versions of the book define different terms.

The DSM-IV has a category called Pervasive Developmental Disorders (PDD) with different sets of criteria for autistic disorder, Asperger's disorder, and pervasive developmental disorder - not otherwise specified (PDD-NOS). The Centers for Disease Control (CDC) has posted the DSM-IV criteria.

The differences between these three terms have not always been very clear to people, including the people who need to diagnose them. Sometimes the same person would be given different labels from different clinicians. To try to get rid of some of this confusion, the most recent version of the DSM, the DSM-V, has defined only one set of criteria and term which is autism spectrum disorder (ASD).

Back to Top

I was just told about the possibility of ASD and I am having mixed feelings.

It is normal to feel a wide range of emotions when you are told about possibly having a medical label, especially if you are not familiar with the condition. Many individuals who have received an Autism Spectrum Disorder (ASD) diagnosis have reported feelings such as anger, confusion, embarrassment, but also relief, validation, and belonging. For some Autistic adults, finding out why they have always felt different from others provides them with a sense of relief and direction. Other newly diagnosed Autistic individuals might feel angry about the diagnosis, especially if they do not have support from their parents, friends, or other relatives. A lot of people become very interested and focused on learning about autism when they first find out; it can become a temporary or permanent special interest. Some people find it helpful to work through their doubts and feelings with others who have had a similar experience. See the section Meeting Others on the Spectrum for more information about how to find peers and support groups. Some people can find therapy helpful.

Whatever your feelings, it is OK to feel them. Over time most people find a balance. Working through all the feelings is a natural process and it takes time.

Back to Top


1American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Firth Edition (DSM-5). Washington, DC: American Psychiatric Association; 2013.

2Nicolaidis, C., Kripke, C.C., Raymaker, D.M. (2014) Primary Care for Adults on the Autism Spectrum Medical Clinics of North America. 98;1169-1191.

3Kapp, SK (2013). Empathizing with sensory and movement differences: Moving toward sensitive understanding of autism. Frontiers in Integrative Neuroscience. 7(38)