ADHD and Working Memory: Why You Lose the Thought Before You Act on It and What Helps

The thought that disappears

ADHD and working memory problems tend to show up in the smallest moments of the day. You walk into the kitchen and stand there, certain you came in for something. You're halfway through telling a story and the point you were heading for has gone. You read the same paragraph three times and still couldn't say what it was about.

Someone asks you to do three things and you're only sure about the first one. None of this means you weren't listening or don't care. More often, the thought was there, and something knocked it out before you had the chance to act on it. Once you know that's what's happening, it's easier to stop blaming yourself and start working around it.

What working memory does

Working memory is the part of your mind that holds information for a few seconds while you use it. It keeps a phone number in your head while you dial it, the end of someone's sentence while you think of a reply, or the reason you got up off the sofa. It's one of the executive functions, alongside planning, organising and getting started. Even without ADHD, it only holds a little, and anything new can push it out.

What the research shows

Working memory is one of the most studied areas of ADHD. A 2005 meta-analysis of 26 studies found children with ADHD did worse on working memory tests than other children, especially tasks about remembering where things were. A 2012 review by Kasper and colleagues described the gap in children as large. In adults, a 2013 meta-analysis of 38 studies found moderate differences, suggesting the difficulties often carry on into adulthood.

These are group averages from lab tests, such as repeating back a list of numbers or remembering where shapes appeared on a screen. Not everyone with ADHD scores low, and a test result can't tell you exactly how it'll play out at home or at work. The NHS page on ADHD in adults lists being easily distracted or forgetful, and finding it hard to follow instructions or finish tasks, among the signs of inattention.

Everyday slip-ups

Working memory problems usually look like something else. Forget the second half of an instruction and it looks like you didn't listen. Lose your point mid-conversation and it looks like you weren't bothered. Reading can go the same way, because you need to hold the start of a sentence until you reach the end. Mental arithmetic at the till, a recipe with six steps or a phone menu asking you to press four different numbers can all fall apart halfway.

Then there's the doorway. Experiments at the University of Notre Dame found that walking from one room to another, in both virtual and real rooms, made people worse at remembering things they'd only just picked up. That research wasn't about ADHD, but it shows how fragile this kind of short-term memory is for everyone, and why the walk to the kitchen is so often where the thought goes missing.

Why brain training disappoints

If working memory is the problem, training it sounds like the obvious answer. Computer programmes such as Cogmed get you practising memory tasks for weeks, and people do get better at those tasks. A 2015 meta-analysis of randomised trials in children and teenagers with ADHD found cognitive training improved working memory test scores, but had limited effects on ADHD symptoms when rated by people who probably didn't know who'd been trained.

The same review found working memory training on its own had no effect on ADHD symptoms. A wider 2013 review by Melby-Lervåg and Hulme, covering children and adults with and without ADHD, found short-term gains in the trained skills that didn't carry over to things like reading, maths or attention. So for most people, relying less on working memory is likely to help more than trying to make it bigger.

Holding onto thoughts

The aim is to get the thought out of your head and into the world as fast as possible, so there's less to hold at once. These are practical ideas people with ADHD often find useful, not treatments, and not all of them will suit you. Pick one or two for the moments that catch you out most and keep whatever sticks.

Capture it within ten seconds

The gap between having a thought and losing it can be tiny, so the capture has to be quicker than the gap. Keep one place for it, whether that's a voice note, a single line in your phone's notes app or a pad by the kettle. Don't sort or tidy anything at that point. "Ring dentist" is enough. You can deal with the list later, once the thought is safely somewhere other than your head.

Say it out loud as you go

When you get up to fetch something, say it while you walk: "charger, charger, charger." It feels a bit daft, but repeating something keeps it active for longer, and hearing it gives you a second way of holding it. The same works for the reason you've opened your laptop, the word you're about to look up or the thing you need from the shop on the way home.

Repeat instructions back straight away

When someone gives you a list of things to do, say it back: "So, the form, then the email to Jo, then lock up." It checks you've got all of it, gives them a chance to fill any gaps, and is normal in plenty of jobs. If it's more than two or three things, ask for it in a message as well. The NHS mentions written instructions as well as spoken ones as a possible reasonable adjustment at work.

Write the next step on the thing itself

Put the reminder where the job is, not in an app you've got to remember to open. Write "needs label printing" on the parcel, "page 2, check the figures" on the printout, or stick a note on the laptop saying exactly where you stopped. When you come back to it, the thing tells you what's next, so you don't have to rebuild it from memory before you can carry on.

Keep it where you can see it

For a lot of people with ADHD, out of sight really does mean out of mind. Leave the letter on the keyboard, the library books on the doormat and the form you need to sign next to the kettle. Open trays and hooks by the door tend to work better than drawers, because a drawer means remembering the thing exists before you can find it.

Hold fewer steps at once

Every step you carry in your head takes up space, and there isn't much of it. Write the steps of a recipe, a form or a phone call on a list and tick them off as you go, so you only ever hold the one in front of you. Use your phone's calculator rather than adding things up in your head, and put directions or a postcode on the screen rather than trying to remember them.

Leave a marker before you switch

Interruptions are where a lot of thoughts get lost. When someone needs you mid-task, take five seconds to leave a marker before you turn round, like typing "NEXT:" and a few words at the bottom of the document. At the end of a work session, write one line about what you were doing and what comes next, so tomorrow starts from the note rather than from a blank.

When to get support

If forgetting things is regularly causing problems at work, at home or in your relationships, the NHS advises seeing a GP to find out what support is available. If you're already diagnosed and it's got harder to manage, your GP or ADHD specialist is the person to talk to. At work, you can ask for reasonable adjustments, and Access to Work can help pay for practical support such as a job coach.

Memory problems can have other causes too. The NHS lists stress, anxiety, depression and sleeping problems among the common, treatable ones, and says to see a GP if memory problems are affecting your day-to-day life. If you've noticed a change that doesn't feel like your usual ADHD, it's worth mentioning when you go.