ADHD and MRI scans: what patients should know

ADHD is assessed from attention, activity, impulse-control and functioning patterns across everyday settings. A conventional brain MRI produces detailed structural images; it does not show a scan pattern that confirms or excludes ADHD in an individual.

Imaging may enter the conversation when symptoms do not fit a straightforward ADHD assessment or when there are additional neurological concerns. Examples include a new seizure, persistent one-sided weakness, unusual headaches with neurological changes, a significant head injury, or findings on examination that need a closer look. In that situation, the scan addresses the additional concern rather than measuring attention or confirming ADHD.

MRI uses a strong magnetic field and radio waves rather than ionising radiation. The scanner can be noisy and enclosed, and remaining still helps produce clear images. Some examinations use an injected contrast agent, depending on the body area and the clinical question.

Tell the imaging team about implanted devices, metal fragments, previous operations, pregnancy or possible pregnancy, kidney problems, allergies, and any previous reaction to contrast. Bring the device details if you have an implant card. Remove metal items as instructed and follow the centre's guidance on food, medicines and arrival time.

If confined spaces, noise or lying still may be difficult, mention this before the appointment. The team can explain positioning, hearing protection, communication during the scan and whether additional support is appropriate. Do not stop prescribed ADHD medicine unless the clinician responsible for the scan or medicine specifically advises it.

Seek emergency care for a first seizure, sudden weakness or numbness on one side, new difficulty speaking, sudden severe confusion, loss of consciousness, or a rapidly developing severe headache with neurological changes. These warning signs require prompt clinical assessment; they should not wait for a routine ADHD appointment or a planned outpatient MRI.

Ask what specific question the MRI is intended to answer, whether contrast is planned, how your implants and medicines affect preparation, and when and how results will be explained. You can also ask what the next step would be if the images are normal or if they reveal an unrelated finding.