Autism’s Clinical Companions: Frequent Comorbidities with ASD

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Children's Doctor

Autism spectrum disorder (ASD) has a number of co-occurring physical and mental health conditions that are crucial for general pediatricians, family doctors, and nonspecialists to be aware of, since they provide the bulk of healthcare services for people with ASD. These include:

These issues can last throughout life, but may also appear or diminish at different developmental stages. Alarmingly, multiple studies show that people with ASD have significantly shorter lifespans not due to autism itself, but to accompanying mental and physical health conditions.

Diagnosis of comorbidities can be challenging because many people with ASD have difficulty recognizing and communicating their symptoms. Physical discomfort might prompt spikes in self-soothing repetitive behaviors as well as irritability, aggression, self-injury, and other challenging behavioral issues. That makes it difficult to tease out whether these behaviors are related to ASD or to physical discomfort caused by a co-occurring condition. A brief overview follows.

Epilepsy or seizure disorders

Epilepsy affects a remarkable 25% to 40% of patients with ASD, compared to 2% to 3% of the general population, and seizures are a major area of concern for families. Research found intellectual disability, an underlying neurologic disorder, family history of epilepsy, and severe cognitive delay increase the risk of epilepsy in patients with ASD.

Symptoms to probe with parents include repeated, unexplained abrupt changes in behavior such as staring spells, stiffening of muscles, involuntary jerking of limbs, or sudden sleepiness or sleep disturbance. Others might be sudden, unexplained, and marked irritability or aggression, or regression in normal development. If a seizure occurs or epilepsy is suspected, the patient should be referred to a neurologist who is familiar with autism-friendly EEG protocols, if possible.

Gastrointestinal disorders

Depending on which study you read, GI disorders affect as many as 85% of patients with ASD. In spite of this, no known genetic or neurologic links have been found to explain this prevalence. Still, it is clear that many children and adults with ASD are quite uncomfortable, perhaps due to GI disorders.

Behavioral clues that a patient may be experiencing pain related to GI problems (diarrhea, constipation, gaseousness, or painful bowel movements) include arching the back, pressing the belly, or gritting teeth. Patients with GERD might strain the neck, push out the jaw, tap the throat, avoid lying down, experience sleep disruption, or refuse food.

It can take some digging to find the root of GI problems in patients with ASD, since many have restricted diets due to sensory sensitivities or parental choice (gluten- and casein-free). In some cases, medication may be causing GI side effects. While some parents report a gluten-free diet helps improve behaviors, research doesn’t back that up.

Feeding or eating challenges

Selective eating and obesity are the two most common feeding or eating disorders for pediatricians to be aware of in their patients with ASD. Thirty percent of children with autism are obese, compared with 13% of the general population. Sensory issues, anxiety, medication side effects, social isolation, and activity level can all be underlying factors and should be discussed with patients and families.

Sleep disorders and disruption

Chronic sleep problems affect anywhere from 50% to 80% of children with autism — and therefore, their parents. Problems include difficulty falling asleep, frequent and prolonged wakening, or extremely early rising. Sleep issues go hand in hand with daytime behaviors and affect quality of life for the entire family. Genetics, medication, and anxiety can all play a role in sleep disturbance. General sleep hygiene interventions can help, and specialists have created parent-guided programs to help improve sleep in children with ASD. In some cases, children with significant sleep disturbances may need to be evaluated by a sleep specialist.

Psychiatric comorbidities

As many as 85% of children with autism also have some form of comorbid psychiatric diagnosis, and 35% are taking at least 1 psychotropic medication as treatment. ADHD, anxiety, and depression are the most commonly diagnosed comorbidities, with anxiety and depression being particularly important to watch for in older children, as they become more self-aware.

ADHD can be extremely challenging to distinguish from ASD, even for experienced clinicians, since the core symptoms of ASD can look like attention problems or hyperactivity (lack of eye contact, repetitive behaviors, etc.). Many primary providers may find it helpful to partner with parents and an ASD specialist, if necessary, to explore medications that will address these symptoms in children with ASD

References and suggested readings

Hyman SL, Stewart PA, Foley J, et al. The gluten-free/casein-free diet: a double-blind challenge trial in children with autism. J Autism Dev Disord. 2016;46(1):205-220.

Autism and Health: A Special Report by Autism Speaks – Advances in Understanding and Treating the Health Conditions that Frequently Accompany Autism. Autism Speaks website. Accessed May 23, 2017.

Strategies to Improve Sleep Toolkits. Autism Speaks website. Accessed May 23, 2017.

Chaidez V, Hansen RL, Hertz-Picciotto I. (2014). Gastrointestinal problems in children with autism, developmental delays or typical development. J Autism Dev Disord. 2014;44(5):1117-1127.

Guan J, Li G. Injury mortality in individuals with autism. Am J Public Health. 2017;107(5):791-793.

Mulloy A, Lang R, O’Reilly M, et al. Gluten-free and casein-free diets in the treatment of autism spectrum disorders: a systematic review. DARE Reviews. Accessed June 8, 2017.

Romero M, Aguilar JM, Del-Rey-Mejías Á, et al. Psychiatric comorbidities in autism spectrum disorder: A comparative study between DSM-IV-TR and DSM-5 diagnosis. Int J Clin Health Psychol. 2016:16(3):266-275.

Spence SJ, Schneider MT. The role of epilepsy and epileptiform EEGs in autism spectrum disorders. Pediatr Res. 2009;65(6):599-606.

Friedlaender E. Next Steps into Adolescence: CHOP’s Dr. Eron Friedlaender discusses pharmacotherapy in ASD (at 13:00). Children’s Hospital of Philadelphia. Accessed June 8, 2017.


Autism Referral Information and Resources

Find information about making a referral and resources for patient families.

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Center for Autism Research (CAR)

In addition to coordinating research on autism spectrum disorder, CAR offers many resources and educational materials.

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