Coexisting Conditions Decrease Likelihood of Response to ADHD Medications

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The patients prescribed stimulants were more likely to not have coexisting conditions than those treated with A2A.

The amount of co-existing conditions for pediatric patients with attention deficit/hyperactivity disorder (ADHD) might help explain why some patients do not respond to certain treatments.

A team, led by Alexis Deavenport-Saman, Department of Pediatrics, Children's Hospital Los Angeles, determined whether conditions coexisting with ADHD in preschool-age children are linked to the choice of stimulants or alpha-2 adrenergic agonists (A2As) or the likelihood of improvement in ADHD symptoms.

The Study

In the retrospective electronic health record review, the investigators examined data from 497 pediatric patients from 7 Developmental Behavioral Pediatrics Research Network (DBPNet) sites. Each patient was younger than 72 months when treated with medication for ADHD between January 1, 2013 and July 1, 2017.

“There are 6.1 million children diagnosed with attention-deficit/hyperactivity disorder (ADHD) in the United States, and 64% have at least one coexisting condition, which may complicate ADHD diagnosis and treatment,” the authors wrote. “The prevalence of ADHD in preschool-age children is reported as 2.4%, based on a recent US population-based study.”

The investigators abstracted coexisting conditions, initial medication prescribed, and whether the medication was linked to improvement in symptoms and adjusted for clustering the analysis of improvement by clinician and site.

Co-Existing Conditions

There was a median child age at the time of medication initiation of 62 month, with the most common coexisting conditions including language disorders (40%), sleep disorders (28%), disruptive behavior disorders (22.7%), autism spectrum disorder (21.8%), and motor disorders (19.9%).

There was no coexisting conditions present in 17.1% of the patient population, there was 1 in 36.8%, and there was at least 3 in 19.3%.


Clinicians initially prescribed stimulants for 64.8% (n = 322) of children and A2A for 35.2% (n = 175).

The patients prescribed stimulants were more likely to not have coexisting conditions than those treated with A2A (22.3% vs. 7.4%; P <0.001).

Both coexisting ASD and sleep disorders were linked to an increased likelihood of starting A2As compared to stimulants (P <0.0005; P = 0.002).

The link between medication treatment and improvement varied by number of coexisting conditions for 0, 1, 2, or ≥3 was 84.7%, 73.8%, 72.9%, and 64.6%, respectively (P = 0.031).

Pediatric patients with at least 3 coexisting conditions were also less likely to respond to stimulants than children with no coexisting conditions (67.4% vs. 79.9%; P = 0.037).

“Among preschool-age children with ADHD, those with ≥3 coexisting conditions were less likely to respond to stimulants than those with no coexisting conditions,” the authors wrote. “This was not found for A2A, but further research is needed as very few children with no coexisting conditions were treated with A2A.”

The study, “Association of Coexisting Conditions, Attention-Deficit/Hyperactivity Disorder Medication Choice, and Likelihood of Improvement in Preschool-Age Children: A Developmental Behavioral Pediatrics Research Network Study,” was published in the Journal of Child and Adolescent Psychopharmacology.