Autism Diagnosis And Prevalence
Autism diagnosis has traditionally been most common in childhood, when differences from neurotypical peers may first become obvious. However, in recent years, there has been a significant increase in the rate of adult diagnosis, particularly as diagnostic criteria have been broadened such that individuals who may not have received an autism diagnosis in childhood may now meet current diagnostic criteria . Note: we use autism to refer to the clinical diagnosis of autism spectrum disorder, as some members of the autism community feel the label disorder produces stigma and emphasises the difficulties associated with autism while minimising the strengths. For similar reasons, we use identity-first language throughout to respect the preferences of a majority of autistic people . Changes to diagnostic criteria which are linked to an increase in overall diagnostic levels include the integration of previously separate diagnostic categories into one autism spectrum disorder category . There have been many studies examining the needs and experiences of individuals who seek an autism diagnosis in adulthood . In particular, there has been a focus on the difficulties experienced by autistic women in obtaining autism diagnoses, for reasons which will be discussed in greater detail below.
Differences In Gender And Sexuality Identification
Sexuality is often discussed within the autistic community, with many observations that identities other than cis–hetero seem to be more common than is observed in the neurotypical population. There have not been many formal studies on this to date, however members of the community speculate that autistic individuals generally have different ideals, perceptions and desires than neurotypicals or simply do not comprehend or agree with society’s expectation, making them more apt to diverge from the norm.
A study looking at the co-occurrence of ASD in patients with gender dysphoria found 7.8% of patients to be on the autism spectrum. Another study consisting of online surveys that included those who identified as nonbinary and those identifying as transgender without diagnoses of gender dysphoria found the number to be as high as 24% of gender diverse people having autism, versus around 5% of the surveyed cisgender people. A possible hypothesis for the correlation may be that autistic people are less capable to conform to societal norms, which may explain the high number of autistic individuals who identify outside the stereotypical gender binary. As of yet, there have been no studies specifically addressing the occurrence of autism in intersex individuals.
Diagnosis Due To Misbehavior
Diagnosis of an Autism Spectrum Disorder often occurs at school and will often come about because inappropriate behavior has called attention to the child. Statistically males are more likely to engage in behaviors that brings them to the attention of school authorities, so possibly female students are more likely to ‘slip under the radar’ when it comes to a mild Autism Spectrum Disorder being diagnosed. This also opens up the possibility of male students with behavioral problems being mistakenly diagnosed with an Autism Spectrum Disorder by an inexperienced practitioner. There have also been accusations made of schools being motivated to diagnose Autism and Asperger’s syndrome in borderline cases in order to attract more funding.
As with many aspects of Autism, Asperger’s syndrome and other Autism Spectrum Disorders, more research is needed before causes of this gender imbalance can be stated with certainty.
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Female Protective Effect Hypothesis
According to the female protective effect hypothesis, more extreme genetic mutations are required for a girl to develop autism than for a boy. In 2012, Harvard researchers published findings suggesting that, on average, more genetic and environmental risk factors are required for girls to develop autism, compared to boys. The researchers analyzed DNA samples of nearly 800 families affected by autism and nearly 16,000 individuals with a variety of neurodevelopmental disorders. They looked for various types of gene mutations. Overall, they found that females diagnosed with autism or another neurodevelopmental disorder had a greater number of harmful mutations throughout the genome than did males with the same disorders. Women with an extra X chromosome, 47,XXX or triple X syndrome, have autism-like social impairments in 32% of cases.
Autism In Boys Vs Girls: Brain Scans Reveal Underlying Reason For Gender Differences In Autism Symptoms
Autistic behavior is different in girls than boys, say Stanford University School of Medicine researchers. Their new study not only provides evidence suggesting girls with autism spectrum disorders have distinct characteristics, it also links such gender differences directly to the brain.
Autism is characterized by three core symptoms: social impairments, communication difficulties, and repetitive/restricted behaviors. Yet, when it comes to high-functioning autism, the boys outnumber girls by four to one, noted the authors. While no one understands the reason for this gender imbalance, many researchers suspect girls with autism may simply display less severe impairments than boys.
The team of Stanford researchers explored this possibility in their current study. For data, they turned to two separate repositories. First, they queried the National Database for Autism Research, which is funded by the National Institutes of Health, using these parameters: ages 7 to 13 years, phenotype ASD, and IQ greater than 70. Their search came up with 128 girls and 614 boys.;
Examining the data, the research team discovered the boys and girls shared similar low scores for social and communication behaviors;;however, the girls had scores much closer to the normal range when they were measured for repetitive and restricted behaviors. What might brain scans reveal about these differences?
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New Research Sheds Light On Previously Under
The findings suggest that we should not blindly assume that everything found in males with autism applies to females.
Dr Meng-Chuan Lai
Autism affects different parts of the brain in females with autism than males with autism, a new study reveals. The research is published today in the journal Brain as an open-access article.
Scientists at the Autism Research Centre at the University of Cambridge used magnetic resonance imaging to examine whether autism affects the brain of males and females in a similar or different way. They found that the anatomy of the brain of someone with autism substantially depends on whether an individual is male or female, with brain areas that were atypical in adult females with autism being similar to areas that differ between typically developing males and females. This was not seen in men with autism.
One of our new findings is that females with autism show neuroanatomical masculinization, said Professor Simon Baron-Cohen, senior author of the paper. This may implicate physiological mechanisms that drive sexual dimorphism, such as prenatal sex hormones and sex-linked genetic mechanisms.
Autism affects 1% of the general population and is more prevalent in males. Most studies have therefore focused on male-dominant samples. As a result, our understanding of the neurobiology of autism is male-biased.
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Describing Differences In Boys And Girls With Autism
A Swedish study looked at a revised version of an autism screening questionnaire to see if girls with ASD had different traits. The researchers found that girls with ASD were more likely than boys with ASD to avoid demands placed on them, to be careless with their appearance and dress, to interact mostly with younger children, and to be very determined. Boys were more likely to lack a best friend, according to the study, published in 2011.8
Another interesting difference: A monotone or “robot-like” voice is considered fairly typical of boys with Asperger’s or high-functioning autism, but not so with girls. Instead, the girls were more likely to speak in a high-pitched, childish or hoarse voice.8
Psychologist Tony Attwood has also noted this difference in some women with Asperger’s. “Their tone resembles a much younger person, having an almost child-like quality,” he stated in Asperger’s and Girls.9
Whether due to culture or biology, girls in the general population are often less aggressive than boys, according to Dr. Attwood. That means girls with ASD are less likely than boys with ASD to have behaviors that trigger a referral to a psychologist or psychiatrist in the first place.
The social difficulties of a passive girl may be discounted by her teachers and parents. A girl’s failure to make eye contact may be mistaken for shyness, coyness or naiveté, rather than seen as a sign of ASD, according to Sheila Wagner, M.Ed, of the Emory Autism Center.10
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A Variety Of Possibilities May Link Asd To The Male Brain
According to some researchers, the reason is that autism is an excessive expression of those aspects of brain development that are already pronounced in the male brain. The extreme male brain theory posits that it is an overdevelopment in the male traits of cognition that causes ASD patients to over-systematize, leading to a breakdown of verbal and social capacities.
Some studies have found correlations between fetal testosterone levels and ASD.
On the other hand, researchers in Canada in 2010 undertook a genetic study of ASD patients and found that around one percent of the males tested had a particular mutation in a certain gene on their X-chromosome. If the mutation were found to be linked to ASD it could explain some of the preponderance of ASD among boys.
And even more recently, scientists in Germany found a positive correlation between a thin cortex and the likelihood of an ASD diagnosis. Since women reliably have greater cortical thickness than men, this could indicate that the male brain is simply more vulnerable to whatever structural changes bring about ASD.
The search for a definitive answer as to why more boys than girls suffer from ASD is only one aspect of the larger search for the causes behind autism and is not likely to be resolved until that central mystery is itself cleared up.
In the meantime, for applied behavior analysts working with ASD patients, the likelihood that most of them will be boys isnt going to change anytime soon.
Autism Symptomology In Girls
Studies have shown that there is a male bias in diagnosing autism due to differing symptoms including fewer restricted and repetitive behaviors and externalizing behavioral problems in females . Social factors make it harder to diagnose autism in girls and they may need to have more behavioral issues or cognitive disability than boys in order to be diagnosed. Girls with autism may score the same on indicators of friendship or empathy as boys, but not the same as typically-developing girls. They want to socialize more than boys with autism, and have higher rates of depression and suicidal thoughts as teens. Preliminary research shows that the hallmark brain differences in autism vs. typical peers seems to hold true for boys, but not girls. A new forthcoming study by Kevin Pelphrey, PhD, director of the Autism and Neurodevelopmental Disorders Institute at George Washington University, will discuss Listening to our Daughters : Insights from the Study of Girls and Women Living with Autism, and is available in as archived webinar at www.IANcommunity.org.
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Gender Differences In Diagnosis
Autism is more commonly diagnosed in males than in females across age groups . When screening the entire population using gold standard assessments, current estimates suggest around three males receive an autism diagnosis for every female; however, in clinical samples who have already received an autism diagnosis, that ratio is higher at over four males to each female . In individuals with intellectual disability, the ratio is closer to 2:1 .
When attempting to account for the discrepancies in diagnosis, researchers have drawn upon two distinct ideas, which are contrasting but not mutually exclusive. One argues that there is something inherent in being female that protects females from the likelihood of developing autism . The other proposes that females may be more likely to develop autism than we currently estimate, but that diagnostic biases and variation in the ways autism is expressed in females mean we do not pick up autism in females to the same degree as males .
What Are The Differences And Similarities In How Boys And Girls Experience Autism
Research suggests that the symptoms of autism spectrum disorder, namely difficulties in social skills, difficulties in communication skills, and restrictive or repetitive behaviors, may look different based on the gender of the person with autism.
Autism is diagnosed more often in males than in females.
For every four males that are diagnosed with autism, only one female is diagnosed with autism.
Research questions the reason for this difference in rate of diagnosis in males versus females.
Some suggest that it may be due to the way autism is diagnosed the symptoms that are used as part of the diagnostic criteria.
However, there may be some level of reality in that males experience autism more often than females .
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The Effect Of High Functioning Autism On Gender Orientation
The Autism Europe conference in Edinburgh had research presentations on the topic of gender dysphoria and its connection to high functioning ASD. Dr. Mark Stokes from;from La Trobe University in Melbourne Australia spoke about his recent study examining this topic.;The results from the international study found a higher percentage of those with ASD have gender distress, ambivalence and/or neutrality.
When compared to controls, individuals with ASD demonstrated significantly higher sexual diversity, reported gender-identities incongruent with their biological sex, and higher gender-dysphoric symptomatology.
The ASD group reported higher rates of asexuality; decreased heterosexual attraction and contact; increased homosexual attraction; ASD females reported higher homosexual contact; and were not concerned with the gender of their romantic partner. ASD individuals who were gender non-conforming reported better relationships with their opposite-sex peers during their schooling years than their gender-conforming peers did. The ASD group reported poorer mental health than controls and belonging to a sexual or gender-diverse group worsened this effect.
Increased non-heterosexuality in ASD may particularly fit predictions from the Extreme Male Brain theory of autism. An androgynous self-concept, gender ambivalence and dissatisfaction with culturally-dictated sex-roles emerged as major themes, which together may permit more fluid sexual-identities.
Living In The Space Between The Sexes
The connection between ASD and gender dysmorphia has gone relatively unnoticed up until now. In a very good article from Spectrum Magazine that talks about what it feels like to have GD, they found that:
Between 8 and 10 percent of children and adolescents seen at gender clinics around the world meet the diagnostic criteria for autism, according to studies carried out over the past five years, while roughly 20 percent have autism traits such as impaired social and communication skills or intense focus and attention to detail. Some seek treatment for their gender dysphoria already knowing or suspecting they have autism, but the majority of people in these studies had never sought nor received an autism diagnosis.
The more awareness we have on this topic the sooner we can offer appropriate testing and support for individuals with ASD, and those who do not identify with the bodies in which they were born.
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Associated Medical & Mental Health Conditions
- Autism can affect the whole body.;
- Attention Deficient;Hyperactivity;Disorder ;affects an estimated 30 to 61 percent;of children with autism.;
- More than half;of children with autism;have one or more chronic sleep problems.;
- Anxiety disorders affect an estimated 11 to 40 percent of children and teens on the autism spectrum.;
- Depression affects an estimated 7% of children and 26% of adults with autism.;
- Children with autism are nearly eight times more likely to suffer from one or more chronic;gastrointestinal disorders than are other children.;
- As many as one-third of people with autism have epilepsy;.;
- Studies suggest that schizophrenia affects between 4 and 35 percent of adults with autism. By contrast, schizophrenia affects an estimated 1.1 percent of the general population.;
- Autism-associated health problems extend across the life span from young children to senior citizens.;Nearly a third of 2 to;5 year;olds;with autism are overweight and 16 percent are obese. By contrast, less than a quarter of 2 to;5 year;olds;in the general population are overweight and only 10 percent are medically obese.;
- Risperidone and aripiprazole, the only FDA-approved medications for autism-associated agitation and irritability.;
Gender Differences In Males And Females With Asd
The above information provides an overview of just some of the differences found in the symptoms of autism spectrum disorder when comparing males and females.
In summary, males and females differ in the following ways when looking at the diagnosis of ASD:
- males are diagnosed at a 4:1 ratio when compared to females
- at a young age , females seem to have more motor deficits and lesson communication deficits when they are identified as meeting criteria for an ASD diagnosis at that time
- as intelligence level increases, females are less likely to be diagnosed with ASD which may have to do with their ability to develop coping strategies to manage their life experiences despite having ASD
- females may display different types of restrictive or repetitive behaviors as compared to males; sometimes these behaviors are less noticeable to outside observers
Reference:
Halladay, A.K., Bishop, S., Constantino, J.N. et al. Sex and gender differences in autism spectrum disorder: summarizing evidence gaps and identifying emerging areas of priority. Molecular Autism6, 36 doi:10.1186/s13229-015-0019-y
Matheis, M., Matson, J.L., Hong, E. et al. J Autism Dev Disord 49: 1219. https://doi.org/10.1007/s10803-018-3819-z
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Why Autism Strikes Mostly Boys
Why does autism strike four times as many boys as girls? The answer may lie in specific biological shielding mechanisms that operate in girls, but not boys, even when both sexes have the same genetic defects associated with the disorder.
That conclusion leapt from the data in a study led by University of Minnesota researcher Nicola Grissom, Ph.D., an assistant professor of psychology. Published in Molecular Psychiatry, the study opens a door to understanding and one day better treating the disorder.
“Researchers have known about the ‘female protective effect’ in autism spectrum disorders for quite a while, but the reasons why girls might be protected while boys are vulnerable have remained mysterious,” Grissom said.
This effect means a boy has a 1-in-42 chance of being diagnosed, but a girl has only a 1-in-189 chance, according to the Centers for Disease Control. Those who do develop the disorder have difficulty in responding to rewards that would otherwise serve as cues that help shape social behavior.