How Does ADHD Affect Brain Energy Metabolism on PET?

PostedOctober 6, 2025

UpdatedOctober 6, 2025

ByMy Patient Advice

Author: Phoebe Carter, MSc | Reviewed by: Dr. Rebecca Fernandez, MBBS

Studies show that ADHD brain metabolism PET scans consistently reveal altered glucose uptake and reduced cerebral metabolism in key brain areas. These metabolic changes are visible during both rest and attention-demanding tasks, suggesting that brain regions don’t always get or use energy efficiently in ADHD.

Early PET research found that adults with ADHD had about 8‑10% lower whole‑brain glucose metabolism, particularly in the prefrontal cortex and premotor cortex, areas important for attention and motor control. More recent studies point especially to reduced metabolism in dorsolateral prefrontal regions and basal ganglia. These findings help explain why people with ADHD often feel fatigued or struggle with tasks that require sustained mental effort, because their brains aren’t using fuel (glucose) as efficiently. Imaging also suggests that glucose transporter function may be less optimal in some ADHD brains, which could further limit metabolic supply.

Common Symptoms & What Imaging Can Guide

Below are symptoms linked to metabolic changes, and how treatment may help:

Feeling Mentally Exhausted, Difficulty Sustaining Effort

Tasks like studying or meetings that require sustained focus may feel draining. Reduced cerebral metabolism in prefrontal regions implies the brain can’t maintain activation as easily. Medication (especially stimulants) can help boost metabolic activity; environmental adjustments like frequent breaks and task variation also help.

Slow Response in Tasks Requiring Attention or Inhibition

You might notice slower reaction times, trouble switching gears, or starting tasks slowly. Since those cognitive control areas show lower glucose uptake, treatments targeting improved energy use, medication and lifestyle measures (diet, exercise), can support improved performance.

While PET imaging doesn’t currently serve as a diagnostic tool in everyday ADHD assessments, these metabolic insights deepen our understanding of ADHD’s biological basis.

Visit providers like ADHD Certify for personal consultations informed by the latest imaging findings.

For a deeper dive into the science, diagnosis, and full treatment landscape, read our complete guide to ADHD brain metabolism PET.

Phoebe Carter, MSc

Author

Phoebe Carter is a clinical psychologist with a Master’s in Clinical Psychology and a Bachelor’s in Applied Psychology. She has experience working with both children and adults, conducting psychological assessments, developing individualized treatment plans, and delivering evidence-based therapies. Phoebe specialises in neurodevelopmental conditions such as autism spectrum disorder (ASD), ADHD, and learning disabilities, as well as mood, anxiety, psychotic, and personality disorders. She is skilled in CBT, behaviour modification, ABA, and motivational interviewing, and is dedicated to providing compassionate, evidence-based mental health care to individuals of all ages.

All qualifications and professional experience stated above are authentic and verified by our editorial team. However, pseudonym and image likeness are used to protect the author's privacy.

Dr. Rebecca Fernandez, MBBS

Reviewer

Dr. Rebecca Fernandez is a UK-trained physician with an MBBS and experience in general surgery, cardiology, internal medicine, gynecology, intensive care, and emergency medicine. She has managed critically ill patients, stabilised acute trauma cases, and provided comprehensive inpatient and outpatient care. In psychiatry, Dr. Fernandez has worked with psychotic, mood, anxiety, and substance use disorders, applying evidence-based approaches such as CBT, ACT, and mindfulness-based therapies. Her skills span patient assessment, treatment planning, and the integration of digital health solutions to support mental well-being.

All qualifications and professional experience stated above are authentic and verified by our editorial team. However, pseudonym and image likeness are used to protect the reviewer's privacy.