How do ADHD memory issues differ from dementia?

PostedNovember 18, 2025

UpdatedJanuary 1, 2026

ByMy Patient Advice

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

Many adults with ADHD worry that increasing forgetfulness could be an early sign of dementia. ADHD and dementia affect memory in very different ways. According to NICE guidance (NG87, 2025) and the NHS, ADHD involves attention and working-memory difficulties, not the progressive memory loss seen in dementia.

ADHD affects attention and working memory

In ADHD, memory lapses are typically caused by inattention, distraction, or difficulty organising information, rather than damage to memory storage. People may forget where they put things, lose track of time, or struggle to recall instructions, but when prompted or reminded, the information usually comes back.

Research from Frontiers in Psychology (2024) shows that ADHD affects the brain’s executive networks, which control focus, sequencing, and short-term recall. With structure, coaching, or medication, these memory difficulties often improve.

Dementia involves memory loss and decline

Dementia, by contrast, is a neurodegenerative condition. It causes progressive loss of long-term and episodic memory, as brain regions like the hippocampus and cortex deteriorate over time. According to RCPsych and NHS dementia guidance, this leads to persistent confusion, forgetting familiar faces, and losing the ability to learn new information, symptoms that don’t improve with reminders or cues.

Studies published in BMJ (2024) and PubMed (2025) confirm that while both ADHD and dementia can affect attention, ADHD symptoms are lifelong and stable, whereas dementia-related memory loss worsens steadily.

Distinguishing the two in practice

Clinically, doctors use age of onset, pattern, and progression to differentiate the two. ADHD symptoms begin in childhood and remain relatively stable through life. Dementia symptoms appear later, progress gradually, and resist compensatory strategies.

Both NICE and RCPsych stress that ADHD itself doesn’t cause dementia, although some older adults with ADHD may face a slightly higher risk of mild cognitive impairment (MCI), the overall risk remains low.

Takeaway

ADHD forgetfulness and dementia memory loss may look similar, but their causes couldn’t be more different. ADHD affects how the brain manages information, while dementia affects whether information can be stored or retrieved. ADHD is lifelong but stable, dementia is progressive. Understanding the difference helps ensure the right care, reassurance, and support at any age.

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.