Autism Spectrum Disorder - Overview

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder primarily affecting an individual's social interaction, communication skills, and behavioral patterns. Features of this disorder include repetitive movements, restricted interests, and heightened sensitivity to environmental stimuli. According to statistics from the World Health Organization, approximately 1% of children worldwide are affected, with a significantly higher prevalence in males.

From academic research to social awareness, the diagnosis and treatment of ASD have become important topics in modern medicine. In recent years, with advances in medical research, public understanding of ASD has shifted from viewing it as a "personality defect" to recognizing it as a form of "neurodiversity." However, early detection of signs and the development of individualized support plans remain challenges faced by families and healthcare teams.

Causes and Risk Factors

Genetic Factors

Genetic studies show that the heritability of ASD can be as high as 80%, with over 200 genes associated with the disorder. Twin studies confirm that if one monozygotic twin is affected, the other has a 70-90% chance of also having ASD. Recent findings also indicate a significant association between abnormalities in the chromosome 15q11.2 region and ASD onset.

• Multiple gene interactions: such as mutations in SHANK3, NEUREXIN1, etc.
• Family history influence: risk increases by 10-30 times in first-degree relatives
• Epigenetic changes: abnormal DNA methylation patterns may affect gene expression

Environmental Factors

While genetics are the primary factor, environmental triggers also play a crucial role. Exposure to certain substances during pregnancy has been shown to increase risk:

• Maternal infections: bacterial or viral infections during mid-pregnancy (e.g., rubella, cytomegalovirus)
• Toxin exposure: pregnant women exposed to pesticides or industrial chemicals
• Premature birth and low birth weight: risk increases fourfold for babies born before 32 weeks

Symptoms

Social Communication Difficulties

Infants with ASD often show a lack of response to facial expressions and may not engage in simple conversations before age 3. Although some communication skills may develop in adulthood, common features include:

• Difficulty interpreting others’ emotions
• Delayed development of non-verbal communication (such as eye contact and gestures)
• Misunderstanding social norms, such as not understanding polite language

Repetitive Behaviors and Special Interests

Patients often exhibit compulsive behavior patterns, such as insisting on specific routes or repetitive object arrangements. They may also have intense interests in particular topics, such as:

• Advanced understanding of mathematical formulas or maps
• Obsessive collection of specific items (e.g., building blocks, license plates)
• Extreme resistance to environmental changes (e.g., lighting adjustments)

Diagnosis

Assessment Process

The diagnostic process typically involves three stages: developmental screening, behavioral assessment, and differential diagnosis. Healthcare teams use standardized tools such as the Autism Diagnostic Observation Schedule-Second Edition (ADOS-2), combined with developmental history analysis. Key assessment indicators include:

• Achievement of social communication developmental milestones
• Frequency and severity of repetitive behaviors
• Abnormal sensory responses (such as hypersensitivity or hyposensitivity to sounds and touch)

Differential Diagnosis

It is necessary to distinguish ASD from other developmental disorders, such as Rett syndrome, Asperger’s syndrome, etc. Clinicians will exclude conditions like hearing impairments, language delays, or pervasive developmental disorders with similar symptoms. The diagnosis report usually includes:

• Detailed developmental history
• Scores from standardized assessment tools
• Integrated opinions from multidisciplinary evaluation teams

Treatment Options

Behavioral Therapy

Applied Behavior Analysis (ABA) is the mainstream therapy, fostering social skills through positive reinforcement. Structured teaching methods (TEACCH) utilize visual cues to help patients organize daily activities. Recently developed "social thinking" therapies focus on improving understanding of others’ intentions.

Medication Therapy

Medications are used to manage comorbid symptoms rather than core ASD symptoms. Common medications include:

• Anxiolytics (such as SSRIs) for anxiety symptoms
• Antipsychotics (such as risperidone) to reduce self-injurious behaviors
• Medications for Attention Deficit Hyperactivity Disorder (such as methylphenidate) to improve attention deficits

Prevention

Currently, there are no definitive methods to prevent ASD, but the following measures can reduce risk factors:

• Regular prenatal check-ups and avoiding environmental toxins during pregnancy
• Maternal nutritional supplementation: adequate folic acid intake (400 micrograms daily)
• Utilization of fetal monitoring systems

Studies show that supplementing folic acid during the first three months of pregnancy can reduce ASD risk by 23%. The Environmental Protection Agency recommends avoiding exposure to pesticides and industrial chemicals, especially during early pregnancy.

When Should You See a Doctor?

If early signs appear, prompt professional assessment is advised:

• Not responding to name by 12 months of age
• Not developing functional speech (e.g., "I want water") by 18 months
• Regression of language skills by 24 months

Other warning signs include: indifference to facial expressions, persistent repetitive movements lasting over 15 minutes, and extreme reactions to sensory stimuli (such as panic from noise or ignoring visual stimuli). It is recommended to seek a professional evaluation within six months of noticing abnormal developmental signs.

 

Frequently Asked Questions

How can I determine if my child needs a professional assessment?

If your child shows delayed responses to eye contact and gestures before 18 months, has not spoken or used simple phrases before age 2, or exhibits repetitive behaviors (such as lining up objects), early medical evaluation is recommended. A professional assessment involves behavioral observation and standardized scales conducted by pediatricians or child psychiatrists.

How can I help improve their social and learning abilities at home?

Parents can provide a sense of security through structured daily routines (such as fixed schedules), use visual cards to facilitate communication, and design short interactive games to train eye contact. For children with shorter attention spans, start with activities lasting 1-2 minutes and gradually extend, using positive reinforcement to encourage active behaviors.

Can diet or supplements improve core symptoms?

There is currently no scientific evidence that specific diets or supplements can directly improve social deficits or repetitive behaviors. However, some children with ASD may have gastrointestinal issues, which can be managed through balanced nutrition planned by a dietitian. Always consult a doctor before using any supplements to avoid unproven or potentially harmful treatments.

Is ASD related to parenting styles?

Absolutely not. ASD is caused by neurodevelopmental differences and has no direct causal relationship with parenting or parent-child interactions. Over-attributing the disorder to parenting may delay early diagnosis; evidence-based interventions should be prioritized.

What are the best early intervention times and methods?

Research indicates that the critical intervention period is between ages 2 and 6. Combining applied behavior analysis (ABA), speech therapy, and social skills training can effectively enhance adaptive functioning. Structured daily training and positive reinforcement involving family participation are core strategies for home-based intervention.