How do working memory deficits in ADHD cause forgetfulness?

PostedNovember 17, 2025

UpdatedNovember 18, 2025

ByMy Patient Advice

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

Forgetfulness is one of the most common and misunderstood symptoms of ADHD. According to NICE guidance (NG87), ADHD affects executive function, particularly working memory, the brain’s ability to hold and manipulate information over short periods. When this system falters, daily life becomes filled with missed appointments, misplaced items, and half-finished tasks.

Why ADHD brains forget more

Recent neuroscience confirms that forgetfulness in ADHD isn’t about motivation, it’s about how the brain works. Studies in PubMed (2025) and Frontiers in Psychiatry (2025) show reduced activation in the prefrontal cortex, especially the areas responsible for storing short-term information and sequencing actions.

The NHS ADHD Taskforce (2025) defines these deficits as part of ADHD’s neurodevelopmental profile. When attention shifts, working memory “drops” information before it can be acted on leading to forgotten tasks, bills, or conversations.

Time blindness and everyday forgetfulness

Working memory and time perception are closely linked. Research in Frontiers in Psychiatry (2024) found that adults with ADHD often underestimate how much time has passed, a phenomenon known as time blindness. This explains why someone might intend to pay a bill “later”, and suddenly discover it’s overdue.

The Royal College of Psychiatrists (CR235, 2023) describes this as “serial forgetfulness” an ongoing chain of missed steps caused by working memory overload and disrupted sequencing.

Evidence-based ways to strengthen memory

According to NHS, NICE, and ADHD UK, the most effective supports are those that externalise memory, moving important reminders out of your head and into the environment:

Digital tools: Repeating reminders, alarms, or app notifications (e.g. Tiimo, Todoist, Google Calendar).

Visual aids: Whiteboards, wall planners, and colour-coded post-its for recurring tasks.

Habit stacking: Pairing new habits (like checking bills) with existing routines.

Therapeutic supports: CBT, ADHD coaching, or occupational therapy can help build consistent routines and reduce emotional overwhelm.

Peer-reviewed research in Frontiers in Psychiatry (2025) shows that combining digital reminders with behavioural coaching can significantly improve consistency and task completion in ADHD adults.

Takeaway

Forgetfulness in ADHD isn’t a flaw; it’s a brain-based difference in working memory and attention. By externalising memory through digital tools, structured routines, and compassionate self-support, it’s possible to stay organised and reduce daily frustration.

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.