Any errors or omissions in the summary below are on me. -SR
Connor Puleo: Anxiety in Youth With and Without ASD: Commonalities and Variations
What does anxiety look like in ASD and how good are we in measuring it? Are there things that seem to be different in terms of anxiety for children on the spectrum? How that might complicate measurement and methodology?
Differential diagnosis in an ASD population is inherently challenging, there's a lack of consensus how to go about it, and in terms of defining what is anxiety and what is ASD. What this means is that anxiety disorders get operationalized in different ways across different studies. So even though there's been an influx of research in anxiety and autism, there's been a lot of variation -- a lot of inconsistencies and a big range of results.
Variations also means limitations in instruments -- lots of the instruments used to measure anxiety are meant for non-autistic kids with anxiety, and therefore are only effective with ASD kids when their anxiety presents in the same way as non-autistic kids. We're not going to know what to do with the variations specific to ASD, and there definitely are some.
So we only know what to do with things that prevent similarly. When we see variations, are they symptoms of autism itself, or of co-occurring anxiety? We want to tease out those variables and determine: are they autism, are they anxiety, or are they something new?
Lot of debate over whether anxiety is ASD can be considered a comorbidity, meaning is it a condition that occurs that is secondary to autism and that presents in the same way it would in a subject without ASD. Sometimes core symptoms of ASD are interpreted as anxiety manifesting as social phobia, when they are actually social disinterest or aversion.
There is a possibility that anxiety in autism is presenting as a unique syndrome, and that co-occurring with autism changes the way anxiety presents. If we can parse out what's attributable to anxiety by coherently measuring it, we can start better interpreting the related genetics, neuroimaging, eye tracing, and cognitive influences and results.
Anxiety disorders have distinct set of treatments, and they are different the treatment for ASD symptoms.
Anxiety in the General Population
70% of kids report that they worry now and then, but that's a good thing -- they do their homework, they don't pet dogs that might bite them. Everyone needs anxiety; too little and you're going to get in trouble, too much and it's limiting -- that's when we're talking about Anxiety Disorder, about behaviors that limit functioning rather than safeguarding behavior.
Anxiety affects 10 to 20% of the general population, in adolescents the prevalence is around 30%.
The big three: Generalized Anxiety Disorder, Separation Anxiety Disorder, and Social Phobia. They are often researched and treated as a collective, which illustrates for us that anxiety disorders are conceptualized as having a cognitive component (this is relevant for cognitive behavioral therapies). The mechanism is same in these three disorders; they differ by the "what" in question.
- Generalized Anxiety Disorder is "What if I don't get my homework done, what if the world ends, what if I'm not perfect."
- Separation Anxiety is "What if I never see my parents again."
- Social Phobia is "What if everyone laughs at me and makes fun of me."
The big three are often comorbid; 67 percent of children who present with one anxiety disorder often have another. They are also at increased risk for depression, oppositionality, ADHD and substance use. Anxiety disorders are also associated with poor academic function, peer rejection, and long-term negative consequences. Anxiety disorders in adulthood lead to lower wages, substance abuse, etc., generally lower quality of life.
Most of the time anxiety disorders do not abate without treatment.
Anxiety and Kids on the Autism Spectrum
Focusing on what is different about anxiety in autism, whether we're seeing anxiety or autism.
Going back to Kanner: In 1943 Donald was a child who was happy to play on slides until other kids arrive, then he was horrorstruck. Is that social phobia, because he thinks kids will laugh at him? Or is it autism, because he's not interested in being around other kids?
Or is it a specific fear associated with ASD, a fear of changing things? Worrying is a core feature of Generalized Anxiety Disorder, but when an ASD child worries about the moon not coming up n the sky, is this the same kind of worry as a non-ASD kid being worried about school? Or is it something different, something specific to autism?
When we see obsessiveness, rigidity, and bursts of panic, is this obsessive-compulsive disorder, where ritualistic behaviors are used to reduce anxiety -- or is it a strong routine interest, and does oppositional behavior result from being denied access to that routine? A lot of the variations with anxiety in autism seem to be different.
Different researchers have reported that in autistic kids, they see less fear about negative social evaluation. They see less self-consciousness and fear of rejection. They see more ritualistic behavior, compulsive behavior, self-injury, and social threats. There are also a lot of phobias -- particularly phobias of loud sounds, or phobias with an unusual focus.
Even though there's a lot of research about autism and anxiety, there's also a huge variability in results. Researchers need to think about how this might influence their outcomes.
Autism has been talked about as the most common comorbidity in children on the spectrum. ASD kids are more at risk for an anxiety disorder than kids with Down syndrome, conduct disabilities, and language disorders. However when we look at the prevalence of anxiety in ASD kids, it's between ... 11% and 84%.
The variation may be due to whether the subjects are from parent report, community, academic samples, etc. And it may be that children whose parents are seeking treatment are only those with more severe anxiety symptoms. It also depends on whether the parents are filling out a pre-determined survey, or if a clinician is interviewing the child. We need to know how the data was captured, the child's home language, etc.; these factors can influence the prevalence data for children on the spectrum.
There is very little agreement on what the most common anxiety disorder is for ASD kids, because every study says a new thing. And this may have to do with the different ways anxiety disorders are conceptualized when they occur in different populations, e.g., OCD has been estimated anywhere between 6 and 37% of children -- but the studies do not always have the same criteria or differentiate between obsessive and ritualistic behaviors.
In one sample of "low functioning" and "high functioning" children, the "high functioning" kids had a higher rate of generalized anxiety disorder, separation and panic disorder; but there were no differences in the rates of social phobias and specific phobias -- exactly the anxiety symptoms that tend to manifest differently in the ASD population.
So how should those different symptoms be classified, how do they compare to typical anxiety disorders? Repetitive behaviors specifically are prime candidates for misclassification as anxiety.
Looking at thoughts related to anxiety disorders is a good way to differentiate kids who have anxiety -- self-reporting. This gets right to the heart of the cognitive aspect of these anxiety disorders, and picking up on the variations with regards to typical anxiety disorders.
Puleo found in her sample that atypical anxiety was present in 46% of kids. 25% did not have an anxiety disorder, ADHD, or a mood disorder -- they had language difficulties associated with ASD, but not psychological comorbidities. They did see a high rate of ADHD, specific phobias, and generalized anxiety.
Regarding typical vs. atypical anxiety disorders, their prevalence, and how often they co-occurred: 37% had no anxiety disorders, 48% presented with classic DSM-4 anxiety disorders, and 46% had atypical symptoms. So the latter two are not mutually exclusive -- 31% of the subjects had both types of anxiety disorders. And a study based on traditional anxiety disorders wouldn't pick up on the atypical symptoms.
Predictors: IQ, language, and cognition are significantly related to the severity of typical anxiety disorders. By comparison, social responsiveness and sensory seeking behaviors that are traditionally associated with autism were not significantly predictive of DSM-4 anxiety. Looking at atypical symptoms, the pattern is almost the opposite. Language and IQ are not predictive of atypical anxiety symptoms.
This study was the first to systematically examine and measure typical versus atypical anxiety presentations in children on the spectrum. It suggests that these types of symptoms are qualitatively and quantitatively distinct, and that anxiety can change its manifestation when it occurs with autism. Puleo noted that as this was the first study it needs replication and refinement.