ADHD News & Research

Study: Cognitive Flexibility Improved by ADHD Stimulant Medication Use

Cognitive flexibility may serve as a useful metric when evaluating children for symptoms of ADHD, monitoring treatment outcomes, and assessing symptom severity, according to the study.

August 11, 2022

Stimulant medication use may significantly improve learning and executive functioning skills in children with ADHD, who typically experience limited cognitive flexibility compared to their peers. This finding comes from a study published in Molecular Psychiatry that found regional neural flexibility may be predictive of ADHD and symptom severity.1

Neural flexibility refers to the brain dynamics thought to underlie cognitive flexibility, or “the ability to selectively switch between mental processes.” Researchers studied the neural flexibility of 180 children with ADHD and 180 typically developing children (TDC) using fMRI and machine learning methods. Compared to the TDC group, decreased neural flexibility was observed in the ADHD group at both the whole brain and sub-network levels, suggesting “a system-wide dynamic reconfiguration in ADHD rather than a disruption limited to specific sub-systems,” according to the researchers.

“Neural flexibility not only potentially links to cognitive flexibility, but also has been reported to predict learning outcomes and executive functions in healthy subjects,” the researchers wrote. “Therefore, neural flexibility might be a useful metric to reflect impaired cognitive flexibility in ADHD subjects.”

The effects of stimulant medication on children with ADHD indicated a significant improvement in cognitive functioning. Among the 180 children with ADHD, 46 were identified as using stimulant medication. Whole brain neural flexibility was significantly higher for the medicated ADHD group compared to the non-medicated ADHD group. No statistical difference was found between the TDC and medicated ADHD group, suggesting that neural flexibility may be used as a sensitive metric “revealing the alterations of intrinsic brain function in response to stimulant medication.”

“Since psychostimulant medications were withheld 24 to 48 hours prior to scanning, the observed ‘recovery’ of neural flexibility in the medication group may reflect the long-term benefit of stimulant medication to brain function.”

Finally, researchers compared regional neural flexibility between the ADHD and TDC groups. They were able to identify key regions of the brain “capable of distinguishing TDC from ADHD, and predicting severity of ADHD symptoms.”

Data was sourced from a publicly available, multi-site ADHD dataset. Due to the limited availability of female subjects, only males were considered in the machine learning models.

“Currently, clinical ADHD diagnosis mainly relies on behavioral assessments after symptoms onset and have potential rater bias during implementation. Our findings could potentially inform efforts at earlier detection for vulnerable youth.”

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1Yin, W., Li, T., Mucha, P.J. et al. (2022). Altered neural flexibility in children with attention-deficit/hyperactivity disorder. Mol Psychiatry.