Conditions comorbid to autism
This high rate of anti-FRα autoantibody positivity was confirmed by Ramaekers et al. who compared 75 children with ASD to 30 non-autistic "controls".
The prevalence of anxiety disorders in children with ASD has been reported to be anywhere between 11% and 84%; the wide range is likely due to differences in the ways the studies were conducted.
[11] A systematic review summarized available evidence on interventions to reduce anxiety in school children with autism spectrum disorder.
Thus, individuals with autism spectrum disorder may also have a diagnosis of ADHD, with the modifiers of a predominantly inattentive, hyperactive, combined, or not otherwise specified presentation.
Individuals with ARFID may have trouble eating due to the sensory characteristics of food (appearance, smell, texture, or taste); executive function disregulation; fears of choking or vomiting; low appetite; or a combination of these factors.
[24] Gastrointestinal symptoms are a common comorbidity in patients with autism spectrum disorders (ASD), even though the underlying mechanisms are largely unknown.
[26] Altered gastrointestinal function accompanied by pain may induce feeding issues and increase perceived negative behaviors, including self injury, in individuals with autism.
[27] Brain fog is a constellation of symptoms that include reduced cognition, inability to concentrate and multitask, as well as loss of short- and long-term memory.
[32][34] They may show problems with proprioception (sensation of body position) on measures of developmental coordination disorder, balance, tandem gait, and finger-thumb apposition.
[36] Seizures, caused by abnormal electrical activity in the brain, can produce a temporary loss of consciousness (a "blackout"), a body convulsion, unusual movements, or staring spells.
Typically, onset of epilepsy occurs before age five or during puberty,[37] and is more common in females and individuals who also have a comorbid intellectual disability.
[38] Although results from studies are mixed, it is estimated that 2.6% of children with an FASD have an ASD as well, a rate almost two times higher than that reported in the general US population.
Neurological manifestations include encephalopathy, stroke, cognitive regression, seizures, cardiopathies[54] (cardiac conduction defects, hypertensive heart disease, cardiomyopathy,[55] etc...), diabetes, visual and hearing loss, organ failure, neuropathic pain and peripheral neuropathy.
NF-1 is an autosomal dominant disorder, which means that mutation or deletion of one copy (or allele) of the NF-1 gene is sufficient for the development of NF-1, although presentation varies widely and is often different even between relatives affected by NF-1.
[61] A 2013 review also found evidence of microglial activation and increased cytokine production in postmortem brain samples from people with autism.
[69] A 2009 study involving adult autistic people found that 40% of those diagnosed with autism met the diagnostic requirements for a co-morbid OCPD diagnosis.
[71] Studies have also found that the presence of psychosis in adulthood is significantly higher in those with autism spectrum disorders, especially those with PDD-NOS, than in the general population.
Recent studies have also found that the core ASD symptoms also generally present in a slightly different way during the childhood of the individuals that will later become psychotic, long before the actual psychosis develops.
Other associated features include stilted speech, a lack of deriving enjoyment from most, if not all, activities, feeling as though one is an "observer" rather than a participant in life, an inability to tolerate emotional expectations of others, apparent indifference when praised or criticised, a degree of asexuality and idiosyncratic moral or political beliefs.
[76] Several studies have reported an overlap, confusion or comorbidity with Asperger syndrome (which has been combined with autism spectrum disorder and no longer appears as a diagnostic label in the DSM-5).
Eugen Bleuler coined the term "autism" to describe withdrawal to an internal fantasy, against which any influence from outside becomes an intolerable disturbance.
[86] The prevalence of reported "unusual sensory behaviors" that affect functioning in everyday life is also higher, ranging from 45 to 95% depending on factors such as age, IQ and the control group used.
[91] Unlike general pediatric insomnia, which has its roots in behavior, sleep disorders in individuals with ASD are comorbid with other neurobiological, medical, and psychiatric issues.
[91] If not addressed, severe sleep disorders can exacerbate ASD behaviors such as self-injury;[92] however, there are no Food and Drug Administration-approved pharmacological treatments for pediatric insomnia at this time.
[93] Studies have found abnormalities in the physiology of melatonin and circadian rhythm in people with autism spectrum disorders (ASD).
[95] Some evidence suggests that melatonin supplements improve sleep patterns in children with autism but robust, high-quality studies are overall lacking.
[4] Tuberous sclerosis is a rare genetic disorder that causes benign tumors to grow in the brain as well as in other vital organs.
[100] Studies have reported that between 25% and 61% of individuals with tuberous sclerosis meet the diagnostic criteria for autism with an even higher proportion showing features of a broader pervasive developmental disorder.
One study found that 23% of girls with Turner syndrome who were included met criteria for a diagnosis of an autism spectrum disorder and the majority had "significant social communication difficulties.
It has been found that special diets that are inappropriate for children with ASD usually result in excessive amounts of certain nutrients and persistent vitamin deficiencies.
