Understanding Autism: Key Facts, Signs and Support

Autism, or Autism Spectrum Disorder (ASD), is a complex developmental condition involving persistent challenges in social interaction, speech and nonverbal communication, and restricted/repetitive behaviors.

The ways in which autism presents can vary greatly from person to person.

According to the latest data from the Centers for Disease Control and Prevention (CDC), autism affects an estimated 1 in 31 children in the United States, a significant increase from previous years, highlighting a growing need for awareness and understanding.

This condition is not a disease, but a different way of thinking, learning and interacting with the world.

This guide provides a comprehensive, evidence-based overview of autism.

We will delve into the core symptoms, the diagnostic process for both children and adults, the nuances of autism in women, and why terms like “high-functioning autism” are being challenged.

You will also find information on co-occurring conditions and effective support strategies.

Read on to gain a deeper understanding of the autism spectrum.

1. What Exactly is Autism Spectrum Disorder (ASD)?

Autism Spectrum Disorder (ASD) is a neurodevelopmental condition, meaning it originates from differences in how the brain develops and processes information.

It is not a mental illness or a disease that can be cured.

The term “spectrum” is crucial because it reflects the wide variation in challenges and strengths among autistic people.

The official diagnostic criteria for autism are outlined in the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition, Text Revision (DSM-5-TR).

A diagnosis requires persistent challenges in two core areas.

Core Area 1: Social Communication and Interaction

This involves ongoing difficulties in using communication for social purposes.

To meet the criteria for an autism diagnosis, an individual must show challenges in all three of the following subcategories:

• Deficits in social-emotional reciprocity: This can range from an unusual social approach and difficulty with the back-and-forth of conversation to a reduced sharing of interests, emotions, or a failure to initiate or respond to social interactions. For example, a child might not respond to their name, or an adult might struggle to understand turn-taking in a conversation.
• Deficits in nonverbal communicative behaviors: This includes challenges with integrating verbal and nonverbal communication, abnormalities in eye contact and body language, or difficulties understanding and using gestures. It can manifest as a total lack of facial expressions or a disconnect between what is said and the person’s expression.
• Deficits in developing, maintaining and understanding relationships: This can involve difficulties adjusting behavior to suit different social contexts, challenges in sharing imaginative play or making friends, or a complete absence of interest in peers.

Core Area 2: Restricted, Repetitive Patterns of Behavior, Interests or Activities

This area is characterized by a need for sameness and predictability.

An individual must exhibit at least two of the following four behaviors:

• Stereotyped or repetitive motor movements, use of objects or speech: This includes simple motor stereotypies like hand-flapping or rocking, lining up toys, or repetitive speech patterns like echolalia (repeating others’ words) or using idiosyncratic phrases.
• Insistence on sameness, inflexible adherence to routines or ritualized patterns of behavior: This can cause extreme distress at small changes, difficulties with transitions, rigid thinking patterns, or needing to take the same route or eat the same food every day.
• Highly restricted, fixated interests that are abnormal in intensity or focus: This might be a strong attachment to unusual objects or a deep, all-encompassing interest in a specific topic like train schedules, astronomy or a particular video game.
• Hyper- or hyporeactivity to sensory input: This involves an unusual response to sensory aspects of the environment. An individual might be indifferent to pain or temperature, have an adverse reaction to specific sounds or textures or show a visual fascination with lights or movement.

Understanding the “Spectrum” and Support Levels

The DSM-5-TR also introduced a framework of support levels to better describe the diversity within the autism spectrum.

These levels are not rigid categories but describe the degree of support an individual needs to function in daily life.

• Level 1: Requiring Support. Individuals at this level may have noticeable social communication challenges without support in place. They may struggle to initiate social interactions and their attempts to make friends are often unsuccessful. Inflexibility of behavior can interfere with functioning in one or more contexts.
• Level 2: Requiring Substantial Support. Individuals show marked deficits in verbal and nonverbal social communication skills, even with supports in place. Their social impairments are apparent, and they have limited initiation of social interactions. Their restricted interests and repetitive behaviors are obvious to a casual observer and interfere with functioning in a variety of contexts.
• Level 3: Requiring Very Substantial Support. Individuals have severe deficits in verbal and nonverbal social communication skills that cause severe impairments in functioning. They initiate social interaction very limitedly and have minimal response to social overtures from others. Extreme difficulty coping with change and other restricted/repetitive behaviors markedly interfere with functioning in all spheres.

As autistic advocate Dr. Stephen Shore famously said, “If you’ve met one person with autism, you’ve met one person with autism”. This quote perfectly captures the heterogeneity of the spectrum.

2. What Are the Common Signs and Symptoms of Autism?

The signs of autism can appear in early childhood, but they are sometimes missed or misinterpreted, leading to a later diagnosis.

The presentation of autism symptoms can change significantly across different life stages.

Signs of Autism in Babies and Toddlers

Early detection is key to accessing supportive interventions.

Parents and caregivers should look for developmental differences, not just delays. According to the CDC, some early signs include:

• By 6 months: Few or no big smiles or other warm, joyful expressions.
• By 9 months: Little or no back-and-forth sharing of sounds, smiles or other facial expressions.
• By 12 months: Little or no babbling, little or no response to their name.
• By 16 months: Very few or no words.
• By 24 months: Very few or no meaningful, two-word phrases (not including imitating or repeating).
• At any age: Avoids or resists eye contact, has a strong preference for being alone, struggles to understand other people’s feelings, or shows repetitive behaviors like rocking, spinning or hand-flapping.

Signs of Autism in School-Aged Children

As social demands increase in school, autism symptoms can become more apparent. A child might:

• Have difficulty making or keeping friends.
• Engage in one-sided conversations, often focused on a specific interest.
• Struggle with non-literal language, like sarcasm or figures of speech.
• Follow a very rigid routine and become distressed by changes.
• Have sensory sensitivities, such as being overwhelmed by loud noises in the cafeteria or the feel of certain clothing.
• Exhibit intense focus on a particular subject, becoming a “mini-expert” on dinosaurs, for example, but showing little interest in other topics.

Signs of Autism in Adults

Many adults live with undiagnosed autism, having developed complex coping mechanisms over the years.

The signs of autism in adults can be subtle and are often mistaken for other conditions like social anxiety or personality disorders.

Common signs include:

• Social Difficulties: Finding it hard to “read” social cues, understand what others are thinking or feeling, or navigate workplace politics. They may feel like they are “acting” or performing in social situations.
• Communication Differences: Preferring direct, literal communication and finding small talk exhausting or pointless. They may be perceived as blunt or rude without intending to be.
• Need for Routine: Feeling most comfortable with a predictable schedule and becoming highly anxious or overwhelmed when plans change unexpectedly.
• Sensory Overload: Feeling drained by environments with bright lights, loud noises, or strong smells (like a supermarket or a concert).
• Intense Interests: Having deep, passionate interests in specific subjects, which can be a source of great joy and expertise but may dominate conversations.
• Stimming (Self-Stimulatory Behavior): Engaging in repetitive movements (like fidgeting, pacing or tapping) to regulate emotions and sensory input, which may be more subtle in adults than in children.

A late diagnosis of autism can be a life-changing experience, providing an explanation for a lifetime of feeling “different”.

3. How is Autism Diagnosed Across the Lifespan?

There is no single medical test, like a blood test or brain scan, to diagnose autism.

A diagnosis is made by a team of specialists based on a comprehensive evaluation of an individual’s behavior and developmental history.

The Diagnostic Process in Children

The American Academy of Pediatrics recommends screening all children for developmental delays at their 9-, 18-, and 30-month well-child visits, with specific autism screenings at 18 and 24 months.

If a screening tool (like the M-CHAT-R) indicates a risk, a more comprehensive evaluation is recommended.

This evaluation is typically conducted by a team that may include a developmental pediatrician, a child psychologist or psychiatrist, a neuropsychologist and a speech-language pathologist. The process involves:

1. Parent/Caregiver Interviews: Gathering a detailed history of the child’s development and behaviors.
2. Direct Observation: Using standardized tools like the Autism Diagnostic Observation Schedule (ADOS-2), which involves a series of structured and semi-structured tasks to observe the child’s social communication and play.
3. Cognitive and Language Testing: Assessing the child’s intellectual and communication abilities to identify strengths and challenges.

The Unique Challenges of Diagnosing Autism in Adults

Diagnosing autism in adults is a growing area of clinical practice, but it comes with unique challenges.

Many adults were missed in childhood because awareness was lower and diagnostic criteria were narrower.

A 2024 study in JAMA Network Open found that diagnosis rates in adults aged 26-34 increased by 450% from 2011 to 2022.

Obstacles to adult diagnosis include:

• Masking or Camouflaging: Many adults, especially women, have learned to consciously or subconsciously hide their autistic traits to fit in. This can make it difficult for clinicians to observe the core characteristics of autism.
• Co-occurring Conditions: Adults with undiagnosed autism are nearly three times more likely to have a co-occurring mood, anxiety, or personality disorder. These conditions can “overshadow” the underlying autism, leading to misdiagnosis.
• Lack of Informants: A childhood developmental history is crucial, but it can be difficult to obtain if parents are deceased or unavailable.
• Provider Shortage: There is a significant shortage of clinicians trained and experienced in diagnosing autism in adults.

Why Are Women and Girls Underdiagnosed?

The historical view of autism as a predominantly “male” condition has created significant diagnostic biases.

Research now shows that autism can present differently in females, leading to under-recognition.

A 2024 review in Neuropsychiatric Disease and Treatment highlights several reasons for this disparity:

• More Subtle Presentation: Girls may have better surface-level social skills, such as making eye contact or using learned social phrases. Their restricted interests may also be more “socially acceptable” (e.g., focused on animals, literature or celebrities) and thus less likely to be flagged as unusual.
• Advanced Camouflaging: Girls and women tend to be more motivated and skilled at masking their social difficulties. They may meticulously study and imitate the behavior of their non-autistic peers, which is mentally exhausting but can hide their underlying challenges.
• Internalized vs. Externalized Behaviors: While boys with autism may be more likely to show externalized behaviors like hyperactivity or aggression, girls are more likely to internalize their struggles, leading to anxiety, depression or eating disorders.

This diagnostic gap means many autistic women don’t receive a diagnosis until adulthood, often after years of being misdiagnosed and misunderstood.

An accurate diagnosis can be a source of immense relief and self-understanding.

4. Why is “High-Functioning Autism” a Misleading Term?

The term “high-functioning autism” is widely used in popular culture and even by some clinicians to describe autistic individuals without an intellectual disability.

However, this term is not an official diagnosis and is increasingly rejected by the autistic community and researchers for being inaccurate and harmful.

The Problem with Functioning Labels

The core issue with labels like “high-functioning” and “low-functioning” is that they are based almost entirely on IQ and verbal ability.

This creates a false dichotomy that fails to capture the complex reality of autism.

A landmark 2019 study published in the journal Autism found that IQ is an “imprecise predictor of functional abilities”.

The researchers analyzed data from over 2,200 autistic children and found that those without intellectual disability (the “high-functioning” group) had adaptive skills—the skills needed for daily living—that were significantly below what their IQ would predict.

As explained by Autism Awareness Australia, the term is damaging for two key reasons:

1. It invalidates challenges: Labeling someone as “high-functioning” dismisses their very real and often significant struggles with executive function, sensory processing and social navigation. It can lead to unrealistic expectations and a denial of necessary support and accommodations.
2. It dehumanizes others: Conversely, the label “low-functioning” can cause others to overlook the strengths, intelligence and potential of individuals who may be non-verbal or require more support. It can lead to a presumption of incompetence.

A More Accurate Approach: Focusing on Support Needs

The modern, more accurate approach is to move away from functioning labels and focus on an individual’s specific support needs, which can vary by context and over time.

An autistic person might excel in their professional life but require substantial support with household management or social planning.

This is why the DSM-5’s levels of support (Levels 1, 2 and 3) are a more useful and respectful framework.

They describe what an individual needs to thrive, rather than applying a simplistic and misleading label to their entire being.

The shift in language reflects a broader move towards the neurodiversity paradigm, which views autism as a natural variation of the human brain, not a deficit to be ranked.

5. What Conditions Commonly Co-occur with Autism?

It is more the rule than the exception for autistic individuals to have one or more co-occurring medical or mental health conditions.

A comprehensive 2023 study in the journal Translational Psychiatry found that 74% of individuals with autism had at least one comorbidity.

Understanding these conditions is critical for providing effective support, as they can significantly impact an individual’s quality of life and may sometimes overshadow the core features of autism.

Common Co-occurring Conditions

• Attention-Deficit/Hyperactivity Disorder (ADHD): This is the most common co-occurring condition. The 2023 study found that ADHD affects over one-third (35.3%) of children with autism. The overlap in symptoms, such as challenges with executive function and attention regulation, can make diagnosis complex.
• Anxiety and Depression: Mental health challenges are extremely common. Research indicates that up to 40% of autistic adults experience depression. Anxiety disorders, including social anxiety and generalized anxiety, are also highly prevalent.
• Gastrointestinal (GI) Disorders: Autistic individuals are significantly more likely to experience chronic GI issues like constipation, diarrhea and food sensitivities. The connection is thought to involve the gut-brain axis, stress and sensory-related dietary restrictions.
• Epilepsy and Seizure Disorders: About one-third of people with autism also have epilepsy. The risk is highest for those who also have an intellectual disability.
• Sleep Disorders: Up to 80% of autistic children and adults experience sleep problems, including difficulty falling asleep, frequent waking, and irregular sleep-wake cycles. These issues can exacerbate behavioral challenges and impact overall functioning.
• Intellectual and Learning Disabilities: While many autistic people have average or above-average intelligence, a significant portion also have co-occurring intellectual disability (21.7%) or a specific learning disability (23.5%), according to the 2023 study.

Properly diagnosing and treating these co-occurring conditions is essential.

Often, addressing an issue like chronic pain from GI problems or untreated anxiety can lead to a dramatic improvement in behavior and well-being.

6. What Causes Autism?

There is no single cause of autism.

Decades of research point to a complex interplay of genetic predispositions and environmental factors that affect early brain development.

It is important to state clearly that vaccines do not cause autism.

This theory has been exhaustively and conclusively debunked by numerous large-scale scientific studies.

Genetic Factors

Genetics play the most significant role in autism.

According to a comprehensive review from StatPearls (NCBI), heritability is estimated to be around 50%, with some studies suggesting even higher figures.

• High Concordance in Twins: Studies of identical twins show that if one twin is autistic, the other has a very high chance of also being autistic.
• Hundreds of Genes Involved: Autism is not linked to a single “autism gene”. Rather, hundreds of different genes, many involved in synapse formation and brain connectivity, have been identified as risk factors.
• De Novo Mutations: In some cases, spontaneous genetic mutations that are not present in the parents can contribute to autism.

Environmental and Perinatal Factors

Environmental factors are thought to act as triggers or modifiers in individuals who are already genetically predisposed.

These are risk factors, not direct causes.

• Advanced Parental Age: Children born to older parents, particularly older fathers, have a slightly higher risk of autism.
• Prenatal and Perinatal Complications: Complications during pregnancy and birth, such as maternal infections (e.g., rubella), gestational diabetes, extreme prematurity, and oxygen deprivation at birth, are associated with an increased risk.
• Prenatal Exposures: Exposure to certain medications (like valproic acid) or environmental toxins during pregnancy has been linked to a higher risk.

It is the combination and interaction of these many factors that are believed to lead to the brain differences that characterize autism.

CDC Autism Prevalence Data (2000-2022)

The table below, with data from the CDC’s ADDM Network, illustrates the rising identified prevalence of autism in 8-year-old children in the U.S. over the last two decades.

This trend is largely attributed to increased awareness and improved diagnostic practices.

Surveillance Year	Birth Year	Prevalence per 1.000 Children	This is about 1 in X children
2022	2014	32.2	31
2020	2012	27.6	36
2018	2010	23.0	44
2016	2008	18.5	54
2014	2006	16.8	59
2010	2002	14.7	68
2000	1992	6.7	150

Source: CDC Autism and Developmental Disabilities Monitoring (ADDM) Network

7. What Support and Strategies Help Autistic Individuals?

Since autism is a lifelong condition, the goal of interventions is not to “cure” it but to support the individual, maximize their strengths and help them navigate a world that is often not designed for them.

The National Autistic Society emphasizes that support should always be person-centered and never aim to make someone “less autistic”.

Evidence-Based Therapies and Interventions

• Applied Behavior Analysis (ABA): One of the most well-known and studied interventions, ABA uses principles of learning to teach skills and reduce challenging behaviors. Modern ABA focuses on positive reinforcement in natural settings. It is also a topic of debate within the autistic community, with some adults reporting negative experiences with older, more rigid forms of the therapy.
• Cognitive Behavioral Therapy (CBT): CBT is highly effective for treating co-occurring anxiety and depression in autistic individuals. It helps people identify and change unhelpful thinking patterns and behaviors.
• Speech and Language Therapy: This therapy helps with the mechanics of speech as well as the social use of language (pragmatics), such as understanding conversational rules and non-verbal cues.
• Occupational Therapy (OT): OT helps individuals develop skills for daily living, including fine motor skills (like handwriting) and managing sensory sensitivities.

Practical Strategies for Daily Life

Simple changes to the environment and communication style can make a significant difference:

• Create a Predictable Environment: Use visual schedules, calendars, and clear routines to reduce anxiety and increase predictability.
• Communicate Clearly and Directly: Avoid sarcasm, idioms and vague instructions. Say what you mean in a literal and straightforward way. Allow extra time for information processing.
• Accommodate Sensory Needs: Provide options like noise-canceling headphones, sunglasses or a quiet space to retreat to when overwhelmed. Be mindful of strong smells, fluorescent lighting and clothing textures.
• Leverage Strengths and Interests: Incorporate an individual’s special interests into learning and leisure activities. This can be a powerful motivator and a bridge to social connection.

Building a strong support network—including family, friends, therapists and peer support groups—is fundamental to the well-being of autistic individuals.

Frequently Asked Questions about Autism

Is autism a disease?

No, autism is not a disease. It is a neurodevelopmental condition, meaning it’s a difference in brain development. It is a natural part of human diversity and cannot be “cured”.

Can autism be cured?

There is no cure for autism, and many in the autistic community do not see it as something that needs curing. Therapies and support can help individuals manage challenges and develop skills, but autism is a lifelong part of a person’s identity.

What is “masking” or “camouflaging”?

Masking is when an autistic person consciously or subconsciously hides their natural autistic traits to fit in with non-autistic (neurotypical) peers. This can involve forcing eye contact or mimicking social behaviors and it is often mentally and emotionally exhausting.

Is Asperger’s Syndrome still a diagnosis?

No. With the publication of the DSM-5 in 2013, Asperger’s Syndrome was folded into the single diagnosis of Autism Spectrum Disorder. People previously diagnosed with Asperger’s are now considered to have autism (often Level 1).

Do vaccines cause autism?

No. This theory has been repeatedly and thoroughly discredited by extensive scientific research. Major health organizations worldwide, including the CDC and WHO, confirm there is no link between vaccines and autism.

Can you develop autism as an adult?

No, autism is a developmental condition that is present from birth. However, it is common for it to go unrecognized and undiagnosed until adulthood, especially in individuals who are adept at masking or have less obvious support needs.

What is stimming?

Stimming (self-stimulatory behavior) refers to repetitive actions like hand-flapping, rocking, or vocalizing. It is a natural way for autistic people to self-regulate their emotions, process sensory information or express excitement. It is generally harmless unless it causes self-injury.

What is the difference between autism and social anxiety?

While they can co-occur, they are different. Social anxiety is a fear of social situations and judgment. In autism, the difficulty is often a fundamental challenge in understanding and navigating social rules, not necessarily a fear of them.

Conclusion

Understanding autism has evolved from viewing it as a rare childhood disorder to recognizing it as a common and diverse spectrum of human experience.

From the latest CDC data showing a prevalence of 1 in 31 children to the growing recognition of late-diagnosed adults, it is clear that autism is an integral part of our society.

Moving beyond outdated labels like “high-functioning” and embracing a support-based, person-centered approach is crucial.

By focusing on individual strengths, providing tailored accommodations, and fostering a culture of acceptance, we can create a world where autistic individuals are not just supported, but are empowered to thrive.

If you or someone you know has questions about autism, the first step is to seek information from reliable sources and consult with a qualified healthcare professional.

Sharing knowledge and personal stories helps build a more inclusive and understanding community for everyone.

What are your thoughts or experiences with autism? Share in the comments below to continue the conversation.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a qualified healthcare provider for diagnosis and treatment of any medical condition.