Matching procedures in autism research: Evidence from meta-analytic studies

Diagnosis technique library

In order to diagnose or understand ASD, there need to be comparisons to other groups of people and the peers of the child with autism. There might be a difference in the mental age of the child compared to their chronological age, which can only be seen through comparisons. Does the child have a delay in reaching developmental milestones that their peers reached? Are their developmental milestones more in line with that of a different chronological age group, or do they have altered responses in behavior than expected to people of the same mental age?

A child with autism might be able to explain and understand where emotions come from without being able to reflect or understand the emotions themselves. This is an altered response.

ASD Diagnostic Comparisons

Prior to DSM-5, there were multiple separate diagnoses under the broad range of the Autism Spectrum, but now they are simply denoted as ASD. The single diagnosis of ASD replaced the subcategories that existed prior. To be diagnosed, the individual must have persistent difficulties in social skills and communication and restricted and repetitive behaviors that have been around since childhood. 
Screening is recommended at 18 and 24 months old during regular clinician visits, though more screenings could be recommended if the child is at higher risk. 

- Diagnostic Screening Tools
- Diagnoses Prior to DSM-5


Diagnosing ASD in Children (DSM-5)

Although autism spectrum disorder is typically diagnosed in children, research shows that more subtle presentations of ASD are often not identified until adulthood. Adult diagnosis is particularly common in autistic women, who are less likely to display stereotypical autistic traits and are more likely to internalize their presentation. Diagnosing autism in adults requires some modification of the typical approach used to diagnose children, including the use of different screening tools. As with child diagnosis, parental input is frequently sought for the diagnosis, but significantly more weight is placed on the individual’s self-report in adult diagnosis. 

Diagnosing ASD in Adults (DSM-5)

There is no medical test for ASD. Rather, experts must study an individual's development and behavior and, using their best logic and existing criteria, suggest a diagnosis. Generally, diagnoses are more likely to be accurate by age 2 or older. 

University of Rochester

Grinnell College

Autism Spectrum Disorder is a neurodevelopmental disorder that affects communication and behavior. It displays symptoms such as impaired communication, lack or impairment in social skills and interactions, and repeated patterns of behaviors that interfere with an individual's ability to cognitively function. These symptoms are almost always present in early development, and are considered to be on a 'spectrum' because of the differences in severity of these symptoms.


Although autism can be diagnosed at any age, it is said to be a “developmental disorder” because symptoms generally appear in the first two years of life. Boys tend to be diagnosed more often than girls by approximately 4x. There is also an overrepresentation of transgender or gender nonconforming people with ASD.

Autism Spectrum Disorder

Verbal

Gestures

Pictures

Text

Drawing

Communication Styles

A 1981 epidemiological study conducted by Lorna Wing to examine sex ratios in children diagnosed with autism revealed the following:
- difference b/w men and women in language and social impairments, and in the way they reacted to their respective environments
- prompted further sex ratio research

Ehlers and Gillberg (1998):
- study on epidemiology of Asperger's syndrome
- found smaller male:female ratio than expected

Matille et. al, (2007):
- hypothesizied that women with autism display superficial social skills and this is what causes them to be misdiagnosed

Koenig and Tsatsanis (2005):
- found that most autism research stemmed from male experiences alone
- Hartrung and Widiger (1998): concluded that when a disorder's symptoms change based on gender, diagnosis will be skewed towards those who outwardly express symptoms that are out of the social norm



Gender Bias in Autism and Asperger's Syndrome

When diagnosed with ASD, one is further classified as level 1, 2, or 3. These classifications correspond with severity of symptoms and dependency, particularly indicating how much support is necessary for that individual’s daily functioning. 

- ASD Level 1
- ASD Level 2
- ASD Level 3
- Limitations of the ASD Levels

Three Functional Levels of ASD

The most common co-occurring disorders with Autism Spectrum Disorder include epilepsy/seizures, sleep disorders, gastrointestinal disorders, ADHD, anxiety, depression, and bipolar disorder. Often, these can go undetected due to the overlapping symptoms of ASD and/or inability to communicate these symptoms. This inability to communicate other discomforts can often result in coping mechanisms consisting of inappropriate behaviors, thus a shift in behavior can indicate presence of a comorbid disorder. 

- ASD and Epilepsy

ASD Co-morbidity with Other Disorders

As our understanding of Autism Spectrum Disorder has evolved, our definition and explanations have evolved as well, modifying diagnostic criteria and labels. Most likely, it will continue to adapt and evolve as we learn more about it, as our current understanding is incomplete. 

ASD Definitions Through Time

ASD Diagnosis Techniques

People with autism and those with intellectual disability often experience stigma and barriers to forming intimate romantic relationships due to deficits in complex social skills, despite often having the same needs for intimacy and sexuality as typically-developing people.

Forming romantic relationsihps as an individual with ASD

Fragile X syndrome is perhaps the most common genetic form of intellectual disability. It results when the trinucleotide repeats (i.e., CGG repeats) in the long arm of the X chromosome number more than 200 repeats, as opposed to the normal 6-50 repeats. This extension of repeats leaves this region of DNA fragile, or prone to breakage. Specifically, the overexpansion causes methylation and transcriptional repression of the Fragile X Mental Retardation 1 gene (*FMR1*), which encodes an important RNA-binding protein that inhibits RNA translation into proteins known as fragile X retardation protein (FMRP). The condition affects 1 in 3600 males and 1 in 8000 females. The reason for this large discrepancy between incidences in biological sexes is due to the fact that genetic females have two X chromosomes rather than one X like genetic males do. Generally speaking, females have one normally functioning *FMR1* on the non-mutated chromosome in each cell, which allows their symptoms to be milder since the amount of abnormal *FMR1* is more variable than in males.

Fragile X Syndrome

- About 50-60% of transition-age youth and adults with autism spectrum disorder obtain work opportunities following participation in vocational rehabilitation programs, mainly working part-time and for low wages
- Programs primarily focus on modifying behavior as opposed to modifying work environments and practices
- The structures of VR programs, availability of services, eligibility criteria, and funding differ greatly by state, as well as how tailored they are to individuals with ASD
- A shift to a knowledge-based economy makes VR services for individuals on the autism spectrum a necessity

Vocational Rehabilitation for Individuals on the Autism Spectrum

Many autistic individuals have at least one other co-occuring psychological condition. Some common co-morbidities of Autism Spectrum Disorder include: 

- Attention-Deficit Hyperactivity Disorder 
- Obsessive-Compulsive Disorder 
- Depression 
- Anxiety Disorders 

Co-occuring Psychological Conditions in Autism Spectrum Disorder 

Applied behavioral analysis, or ABA therapy, is rooted in understanding learning and behavior. This therapy is intended to help people with ASD learn skills and behaviors to help them live more fulfilling lives. Such as:

- coping mechanisms
- social skills
- communication skills
- self-care
- play, leisure activities
- motor skills

ABA Therapy

The DSM-5 criteria for children with ASD includes deficits in sensory processing, specifically sensory modulation. Any sensory modality may be affected but some evidence suggests that individuals with ASD have a greater frequency of sensory deficits in the domains of taste and smell, as well as tactile sensitivity. 

- neurobiology of sensory symptoms in ASD

Sensory Processing Deficits in Autism Spectrum Disorder

- mental/speech deficits or impairment
- sleep difficulties
- if smiling, laughing, and/or head flapping is a repetitive behavior this could also be a symptom of autism since repetitive behaviors are a part of autism.

Angelman Syndrome and Autism Spectrum Disorder: Common Symptoms

Social Anxiety Disorder and Autism Comparison

Reference for Autism and Social Anxiety Disorder

Avoidant Personality Disorder and Autism Comparison

Neff, M. (n.d.). Avoidant Personality Disorder vs Autism. Neurodivergent insights. https://neurodivergentinsights.com/misdiagnosis-monday/avoidant-personality-disorder-vs-autism




Avoidant Personality Disorder and Autism Comparison Reference 

Autism Spectrum Disorder (ASD) is a category of neurodevelopmental disorders defined by core challenges in social interaction and communication, alongside the presence of restricted and repetitive patterns of behavior.

Autism Spectrum Disorder (ASD) Core Deficits

The capacity for independent living among adults with Autism Spectrum Disorder varies. While individuals with more developed language and intellectual skills may be able to live and work on their own, this is not the reality for the majority. For many, the persistence of ASD symptoms creates significant impairments in various life domains, making it difficult to manage essential daily tasks like personal hygiene, finances, and meal preparation.

Learn Before

Related

Learn After