Autism spectrum disorder (ASD) is a complex neurodevelopmental condition that affects communication, social interaction, and behavior. The current prevalence of autism in the United States is approximately 1 in 31 children (3.2% of 8-year-olds), with ASD being 3.4 times as prevalent among boys (4.9%) as among girls (1.4%). Understanding autism's causes, identifying the condition early, and implementing evidence-based treatments are crucial for supporting individuals on the spectrum and their families.
While the exact causes remain under investigation, research shows that both genetic and environmental factors play important roles in autism development. This article explores current knowledge about autism spectrum disorder, including its characteristics, causes, diagnostic considerations, and treatment approaches based on the latest scientific evidence.
Table of Contents
- What Is Autism Spectrum Disorder?
- Causes and Risk Factors
- Signs and Symptoms
- Gender Differences in Autism
- Co-occurring Conditions
- Diagnosis and Assessment
- Treatment Approaches
- Living with Autism
- Frequently Asked Questions
- How Therapy Can Help
What Is Autism Spectrum Disorder?
Autism spectrum disorder encompasses a group of neurodevelopmental conditions characterized by differences in social communication and interaction, along with restricted interests and repetitive behaviors. Autism is now understood not as a single condition, but as a group of neurodevelopmental conditions that affect social interaction and communication and are characterized by restricted and repetitive behaviors. The term "spectrum" reflects the wide variation in challenges and strengths possessed by each person with autism.
People with autism have a wide range of symptoms, which can include differences in social and communication behaviors, intellectual disabilities, and other physical and mental health conditions. People with autism also have a wide range of health care and service needs. Some individuals may require substantial support in daily life, while others live independently and may not receive a diagnosis until adulthood.
The DSM-5-TR (Diagnostic and Statistical Manual of Mental Disorders, 5th edition, text revision) defines autism spectrum disorder by two core criteria:
- Persistent deficits in social communication and social interaction across multiple contexts
- Restricted, repetitive patterns of behavior, interests, or activities
Causes and Risk Factors
Genetic Factors
Autism's etiology is multifactorial, involving both genetic and environmental influences. Hundreds of genes increase the likelihood of autism, with heritability estimates of approximately 80% based on family studies. Genes associated with autism are highly expressed during fetal brain development and converge on biological pathways involving synaptic signaling, chromatin remodeling, inflammatory responses in oligodendrocytes, and myelination.
The combined effects of rare genetic variants and polygenic liability contribute to autism. Rare inherited and spontaneous genetic mutations are identified in a subgroup of autistic individuals. These include copy number variants and protein-disrupting variants (e.g., deletion and duplication at 16p11.2, duplication at 15q12, and alterations in CHD8, PTEN, SCN2A, and SHANK3). These mutations are not exclusive to autism and are also associated with intellectual disability, epilepsy, and motor dysfunction. Most autism cases are related to common inherited genes of low individual effect that exert additive effects in a polygenic manner.
Environmental Factors
Environmental factors also increase autism likelihood, accounting for approximately 40% of variance in twin studies. Familial factors include advanced parental age; short interpregnancy interval; and maternal autoimmune disease, hypertension, obesity, diabetes, or infection during pregnancy. Fetal exposures to air pollutants, pesticides, or medications such as valproate or selective serotonin reuptake inhibitors have also been associated with autism, although no association is found for the latter when maternal psychiatric conditions are accounted for.
Some studies have linked autism to prenatal exposure to acetaminophen; however, a recent study of over 2 million children found no association when familial factors were controlled. Prenatal folic acid supplementation is associated with decreased autism likelihood and may ameliorate the impacts of neurotoxicants.
Gene-Environment Interactions
Research increasingly recognizes that autism results from complex interactions between genetic susceptibility and environmental exposures during critical developmental periods. Exposure to harmful environmental factors can change the expression of key developmental genes in critical periods of embryo formation and increases the risk of genomic imprinting diseases such as autism. None of the environmental factors is sufficient to yield autism, but rather a collection of them can be involved in the incidence of autism.
Signs and Symptoms
Core Features
Autism spectrum disorder typically appears in early childhood, though some individuals may not receive a diagnosis until later in life. Core features include:
Social Communication Challenges:
- Difficulty with back-and-forth conversation
- Reduced sharing of interests or emotions
- Challenges in developing and maintaining relationships
- Differences in nonverbal communication (eye contact, facial expressions, gestures)
Restricted and Repetitive Behaviors:
- Repetitive movements or speech patterns
- Insistence on sameness and routines
- Highly restricted, fixated interests
- Hyper- or hypo-reactivity to sensory input
Early Signs
Nationally, the median age of diagnosis is just under 4 years old (47 months). In New Jersey, the median age of diagnosis is lower at 43 months. Early signs that may indicate autism include:
- Limited or no eye contact
- Not responding to their name by 12 months
- Not pointing to show interest by 14 months
- Not playing "pretend" games by 18 months
- Unusual reactions to sensory experiences
- Loss of previously acquired skills
Gender Differences in Autism
Prevalence and Diagnosis Disparities
Three to four times as many boys as girls are diagnosed with ASD, a long-standing pattern confirmed in a 2023 Autism Research article that argues for sex-balanced studies of autism. However, this disparity may not reflect true prevalence differences but rather diagnostic bias and differences in presentation.
It is frequently reported that females are likely to receive an autism diagnosis at a later age than their male counterparts, despite similar levels of autistic traits. It has been suggested that this delay in diagnosis may in part reflect the propensity of females, more than males, to engage in camouflaging behaviors that reduce the appearance of autism-related traits.
Camouflaging and Masking
Even young girls with ASD may camouflage their symptoms, which may diminish the chance of getting a diagnosis. Females with ASD engaged in camouflaging more than males with ASD. Additionally, camouflaging was positively correlated with severity of mood symptoms in males with ASD and with executive functioning in females with ASD. This suggests that the same ASD-related phenomenon, camouflaging in this case, may manifest differently in males versus females, resulting in a potential differential risk for psychopathology.
Diagnostic Bias
Current research consistently reports that ASD is diagnosed substantially more often in males than in females, with male-to-female ratios commonly cited around 3:1, although some studies suggest even wider disparities. However, a growing body of evidence challenges the assumption that these numbers reflect true prevalence differences. Instead, the discrepancy is increasingly attributed to limitations in diagnostic frameworks and a longstanding neglect of gender-specific presentations of autism. Standard diagnostic tools, including the Autism Diagnostic Observation Schedule (ADOS-2) and the Autism Diagnostic Interview—Revised (ADI-R), were developed and validated primarily using male samples.
Co-occurring Conditions
The American Psychiatric Association recently highlighted that more than 95% of people with autism spectrum disorder (ASD) have at least one additional disorder, and that many people have multiple types of comorbid difficulties. These coexisting conditions include intellectual disability, sleep, eating and elimination problems, epilepsy, gastrointestinal disorders, cerebral palsy, brain lesions, speech problems, visual and hearing disorders, genetic disorders, Tourette syndrome, and a wide range of emotional and behavioral problems. Typical coexisting disorders are anxiety disorders, mood disorders, and attention deficit hyperactivity disorder (ADHD).
Common Co-occurring Conditions
Mental Health Conditions:
- Anxiety disorders (affecting up to 40% of individuals with autism)
- Depression (particularly common in adolescents and adults)
- ADHD (frequently co-occurs with autism)
- Obsessive-compulsive behaviors
Medical Conditions:
- Epilepsy affects a remarkable 25% to 40% of patients with ASD, compared to 2% to 3% of the general population, and seizures are a major area of concern for families. Research found intellectual disability, an underlying neurologic disorder, family history of epilepsy, and severe cognitive delay increase the risk of epilepsy in patients with ASD.
- Sleep disorders are significant problems in individuals with autism, present in about 80% of them. GI problems are significantly more common in children with ASD, occurring in 46% to 84% of autistic children.
- Sensory processing differences
- Feeding and eating challenges
Impact on Quality of Life
Alarmingly, multiple studies show that people with ASD have significantly shorter lifespans not due to autism itself, but to accompanying mental and physical health conditions. Diagnosis of comorbidities can be challenging because many people with ASD have difficulty recognizing and communicating their symptoms. Physical discomfort might prompt spikes in self-soothing repetitive behaviors as well as irritability, aggression, self-injury, and other challenging behavioral issues.
Diagnosis and Assessment
Current Diagnostic Approach
Autism diagnosis typically involves a comprehensive evaluation by a multidisciplinary team. ASD screening is recommended for all children at nine, 18, 24, or 30 months old to assess risk. If screening indicates some related symptoms are present, then a series of diagnostic interviews are completed. The presence of concurrent disorders should also be investigated since there is a higher correlation between ASD and diagnoses such as cognitive or language impairment, attention deficit and hyperactivity disorder (ADHD), or epilepsy. Early intervention is highly important for the best outcomes, and treatment options can include chronic behavioral, psychosocial, pharmacological, and complementary therapies, which cater to the individual's specific symptomatology.
Importance of Early Identification
Research shows that access to needed services and supports early in life can promote people's health and well-being over the long term. Early diagnosis allows for:
- Earlier intervention services
- Better developmental outcomes
- Support for families
- Educational planning
Diagnostic Challenges in Females
Women on the autism spectrum are disproportionately underdiagnosed or misdiagnosed due to multiple overlapping factors, including the male-centered structure of the diagnostic criteria, high rates of psychiatric comorbidities that obscure autistic traits, and gender-based social expectations. One of the most significant challenges is the historical development of diagnostic tools and frameworks based predominantly on male populations, resulting in a clinical model that fails to adequately capture how autism manifests in girls and women. Standardized instruments such as the Autism Diagnostic Observation Schedule and the Autism Diagnostic Interview—Revised frequently lack sensitivity to the subtle presentation of ASD in females, particularly in those with average or above-average intellectual functioning who may engage in masking behaviors or mimic neurotypical social patterns.
Treatment Approaches
Evidence-Based Interventions
An evidence-based practice is "an instructional/intervention procedure or set of procedures for which researchers have provided an acceptable level of research that shows the practice produces positive outcomes for children, youth, and/or adults with ASD" (The National Professional Development Center [NPDC], 2023). The NPDC identified interventions and EBPs to specifically teach students with ASD skills and concepts to improve challenges associated with an Autism Spectrum Disorder. These interventions were identified based on extensive research that was conducted with various populations. To date, 28 interventions have been identified by the NPDC as EBPs.
Behavioral Interventions
The search yielded 289 reports of 252 studies, representing 13,304 participants and effects for 3,291 outcomes. When contributing effects were restricted to those from randomized controlled trials, significant summary effects were estimated for behavioral interventions on social emotional or challenging behavior outcomes (Hedges' g=0.58, 95% confidence interval 0.11 to 1.06; P=0.02), developmental interventions on social communication (0.28, 0.12 to 0.44; P=0.003); naturalistic developmental behavioral interventions on adaptive behavior (0.23, 0.02 to 0.43; P=0.03), language (0.16, 0.01 to 0.31; P=0.04), play (0.19, 0.02 to 0.36; P=0.03), social communication (0.35, 0.23 to 0.47; P<0.001), and measures of diagnostic characteristics of autism (0.38, 0.17 to 0.59; P=0.002); and technology-based interventions on social communication (0.33, 0.02 to 0.64; P=0.04) and social emotional or challenging behavior outcomes (0.57, 0.04 to 1.09; P=0.04).
Intervention Intensity and Outcomes
Meta-regression models were constructed to determine whether each index of intervention amount was associated with effect sizes for each intervention type, while controlling for outcome domain, outcome proximity, age of participants, study design, and risk of detection bias. The primary predictor of interest was intervention amount, quantified using 3 different metrics (daily intensity, duration, and cumulative intensity). The primary outcomes of interest were gains in any developmental domain, quantified by Hedges g effect sizes.
Pharmacological Approaches
While there is no cure for ASD, certain medications can be used to manage specific symptoms associated with ASD, such as behavioral problems, attention deficits, anxiety, and mood swings that are common in individuals with autism. Medication is often used as part of a comprehensive intervention program designed to improve the quality of life and daily functioning of the patient. Medications commonly used for ASD symptom management include antipsychotics, antidepressants, stimulants, and anxiolytics. For example, two antipsychotics, risperidone and aripiprazole, have been approved by the FDA for the treatment of stereotypic and aggressive behavior in children and adolescents with ASD. In addition, selective serotonin reuptake inhibitors (SSRIs) may be helpful in managing anxiety and depressive symptoms in individuals with ASD.
Emerging and Complementary Approaches
As novel pharmacological treatments were addressed, namely oxytocin, bumetanide, acetylcholinesterase inhibitors, and memantine, the major takeaway is that more conclusive evidence is needed on efficacy and long-term benefits before making any official recommendations. Other complementary methods such as music therapy and the addition of melatonin to other behavioral therapies have proven to be beneficial for ASD symptom severity and associated sleep disorders, respectively.
Living with Autism
Strengths and Challenges
While autism presents challenges, many individuals on the spectrum possess unique strengths and abilities. These may include:
- Attention to detail
- Pattern recognition
- Strong memory for facts
- Creative problem-solving
- Specialized knowledge in areas of interest
Support Across the Lifespan
We're also supporting research to find better ways to meet the individual needs of people with autism. This includes research to improve early autism screening so that children with autism can be connected with appropriate services and supports as early as possible. This also includes research on supporting people with autism as they age, from childhood to adolescence and throughout adulthood.
Family and Community Support
Supporting individuals with autism requires a comprehensive approach involving:
- Family education and support
- School-based interventions
- Community inclusion programs
- Transition planning for adolescents and adults
- Employment support services
Frequently Asked Questions
What causes autism spectrum disorder?
Autism's etiology is multifactorial, involving both genetic and environmental influences. Research shows that autism results from a complex interaction of genetic factors (accounting for about 80% of risk) and environmental influences (about 40% of variance). No single cause has been identified, and vaccines do not cause autism.
At what age can autism be diagnosed?
Nationally, the median age of diagnosis is just under 4 years old (47 months). However, autism can be reliably diagnosed as early as 18-24 months in some cases. Early diagnosis is important because it allows for earlier intervention, which can lead to better outcomes.
Are there gender differences in autism diagnosis?
Yes, significant gender differences exist. ASD is 3.4 times as prevalent among boys (4.9%) as among girls (1.4%). However, females are often diagnosed later than males and may present differently, often engaging in camouflaging behaviors that mask autistic traits.
What other conditions commonly occur with autism?
More than 95% of people with autism spectrum disorder (ASD) have at least one additional disorder. Common co-occurring conditions include anxiety disorders, ADHD, depression, epilepsy, sleep disorders, and gastrointestinal issues.
What treatments are available for autism?
Treatment typically involves a combination of behavioral interventions, educational supports, and sometimes medication for co-occurring conditions. Due to the lack of specific treatment methods, ASD treatment primarily relies on behavioral interventions, supplemented by symptomatic pharmacological treatments. Behavioral interventions can significantly improve children's self-care abilities and quality of life while also promoting social skills and communication, and reducing disability and comorbidity rates.
Can adults be diagnosed with autism?
Yes, many individuals are not diagnosed until adolescence or adulthood, particularly women and those with subtle presentations. Adult diagnosis can provide important insights and access to supports and services.
How Therapy Can Help
Therapy plays a crucial role in supporting individuals with autism and their families. Behavioral interventions can significantly improve children's self-care abilities and quality of life while also promoting social skills and communication, and reducing disability and comorbidity rates. ASD intervention methods should primarily focus on those proven effective through evidence-based practice, adhering to individualized, multidimensional, and multidisciplinary approaches, thereby promoting the development and establishment of efficient and personalized intervention strategies.
Find a Therapist
If you or a loved one is seeking support for autism spectrum disorder, finding the right therapist is an important step. GoodTherapy's directory can help you locate qualified professionals who specialize in:
- Autism spectrum disorders
- Behavioral interventions
- Family therapy
- Social skills training
- Cognitive behavioral therapy
- Speech and language therapy
Many therapists offer comprehensive evaluations and can work collaboratively with other professionals to provide integrated care. Early intervention and ongoing support can make a significant difference in quality of life for individuals on the autism spectrum.
[Search for a therapist in your area](https://www.goodtherapy.org/find-therapist.html) who specializes in autism spectrum disorder and related conditions.
References:
- [Search for a therapist in your area](https://www.goodtherapy.org/find-therapist.html) who specializes in autism spectrum disorder and related conditions.
- American Psychiatric Association. (2022). Diagnostic and statistical manual of mental disorders (5th ed., text rev.). https://doi.org/10.1176/appi.books.9780890425787
- Andrade, C. (2025). Autism spectrum disorder, 1: Genetic and environmental risk factors. Journal of Clinical Psychiatry, 86(4), e24m15274. https://doi.org/10.4088/JCP.24m15274
- Autism Society. (2023). National statement: Autism Society addresses increased autism prevalence rates in 2023 CDC report. Retrieved March 28, 2026, from https://autismsociety.org/autism-society-addresses-increased-autism-prevalence-rates-in-2023-cdc-report/
- Belcher, H. L., et al. (2024). Underdiagnosed and misunderstood: Clinical challenges and educational needs of healthcare professionals in identifying autism spectrum disorder in women. International Journal of Environmental Research and Public Health, 21(8), 1045. https://doi.org/10.3390/ijerph21081045
- Centers for Disease Control and Prevention. (2025). CDC's 2025 Community Report on Autism. Retrieved March 28, 2026, from https://www.cdc.gov/autism/communication-resources/community-reports.html
- Cruz, S., Conde-Pumpido Zubizarreta, S., Costa, A. D., et al. (2024). Is there a bias towards males in the diagnosis of autism? A systematic review and meta-analysis. Neuropsychology Review, 35(1), 153–176. https://doi.org/10.1007/s11065-023-09630-2
- Grigoryan, A., et al. (2025). Unraveling the genetic and environmental risk factors of autism spectrum disorder through a case-control study in Armenia. Health Science Reports, 8(5), e2145. https://doi.org/10.1002/hsr2.2145
- Harrop, C., et al. (2024). Are the diagnostic rates of autistic females increasing? A comparison of diagnostic trends. Journal of Child Psychology and Psychiatry, 65(3), 456–468. https://doi.org/10.1111/jcpp.13890
- Kaye, D., et al. (2024). Emerging treatments and therapies for autism spectrum disorder: A narrative review. Cureus, 16(7), e64410. https://doi.org/10.7759/cureus.64410
- Khachadourian, V., Mahjani, B., Sandin, S., et al. (2023). Comorbidities in autism spectrum disorder and their etiologies. Translational Psychiatry, 13, 71. https://doi.org/10.1038/s41398-023-02374-w
- Kim, H. J. (2024). Common comorbid condition of patients with autism spectrum disorder and pharmacotherapy for patients with autism spectrum disorder. Clinical and Experimental Pediatrics, 67(1), 45–52. https://doi.org/10.3345/cep.2023.01030
- Li, M., Wang, L., Zhang, Y., et al. (2024). New advances in the diagnosis and treatment of autism spectrum disorders. European Journal of Medical Research, 29, 322. https://doi.org/10.1186/s40001-024-01916-2
- Love, C., Sominsky, L., O'Hely, M., et al. (2024). Prenatal environmental risk factors for autism spectrum disorder and their potential mechanisms. BMC Medicine, 22(1), 393. https://doi.org/10.1186/s12916-024-03613-7
- Micai, M., Fatta, L. M., Gila, L., et al. (2023). Prevalence of co-occurring conditions in children and adults with autism spectrum disorder: A systematic review and meta-analysis. Neuroscience & Biobehavioral Reviews, 155, 105436. https://doi.org/10.1016/j.neubiorev.2023.105436
- Milner, V., Colvert, E., Hull, L., et al. (2024). Does camouflaging predict age at autism diagnosis? A comparison of autistic men and women. Autism Research, 17(3), 626–636. https://doi.org/10.1002/aur.3059
- National Institute of Mental Health. (2025). Autism spectrum disorder (ASD). Retrieved March 28, 2026, from https://www.nimh.nih.gov/health/statistics/autism-spectrum-disorder-asd
- National Professional Development Center on Autism Spectrum Disorder. (2023). AFIRM resources: Evidence-based practices. Retrieved March 28, 2026, from https://autismpdc.fpg.unc.edu/npdc-resources
- Ridout, S., & Eldevik, S. (2024). Measures used to assess treatment outcomes in children with autism receiving early and intensive behavioral interventions: A review. Review Journal of Autism and Developmental Disorders, 11, 607–619. https://doi.org/10.1007/s40489-023-00355-9
- Sandbank, M., Bottema-Beutel, K., Crowley LaPoint, S., et al. (2023). Autism intervention meta-analysis of early childhood studies (Project AIM): Updated systematic review and secondary analysis. BMJ, 383, e076733. https://doi.org/10.1136/bmj-2023-076733
- Sandbank, M., Pustejovsky, J. E., Bottema-Beutel, K., Caldwell, N., Feldman, J. I., Crowley LaPoint, S., & Woynaroski, T. (2024). Determining associations between intervention amount and outcomes for young autistic children: A meta-analysis. JAMA Pediatrics, 178(8), 763–773. https://doi.org/10.1001/jamapediatrics.2024.1832
- Shaw, K. A., Williams, S., Patrick, M. E., et al. (2025). Prevalence and early identification of autism spectrum disorder among children aged 4 and 8 years — Autism and Developmental Disabilities Monitoring Network, 16 Sites, United States, 2022. MMWR Surveillance Summaries, 74(SS-2), 1–22. https://doi.org/10.15585/mmwr.ss7402a1
- Talantseva, O. I., Romanova, R. S., Shurdova, E. M., et al. (2023). The global prevalence of autism spectrum disorder: A three-level meta-analysis. Frontiers in Psychiatry, 14, 1071181. https://doi.org/10.3389/fpsyt.2023.1071181
- Tsirgiotis, J. M., Young, R. L., & Weber, N. (2024). A comparison of the presentations of males and females with autism spectrum disorder and those narrowly below the diagnostic threshold. Autism, 28(4), 892–905. https://doi.org/10.1177/13623613231190682
- Wang, J., et al. (2024). A systematic review and meta-analysis of autism screening and diagnosis in children using video-assisted telehealth technology. BMC Medicine, 22, Article 45. https://doi.org/10.1186/s12916-024-03290-6
- Zhang, H., et al. (2025). A review of therapeutic approaches for autism spectrum disorder. Brain Sciences, 15(12), 1280. https://doi.org/10.3390/brainsci15121280
