Why Diagnosing ADHD Remains a Major Challenge for Doctors

It's just generally a really good thing to do. People with ADHD may have lower lifetime earnings, greater risk of relationship breakdowns. If we look at treatments for ADHD, this is the one I'd put my money on. Hello and welcome to Instant Genius, brought to you from the team behind BBC Science Focus. I'm Jason Goodger, commissioning editor at BBC Science Focus. In today's episode, we're joined by Professor Ellie Dummit, a neuroscientist based at King's College London to talk about the latest thinking surrounding ADHD. So, welcome to the podcast. Thanks so much for joining us. Thank you for having me.

Oh, it's great to have you here. So, today we're talking all about ADHD. And I'd say that although awareness of this condition has grown considerably over recent years, it's still quite often misunderstood. So, I think a good place to start is first off, I think a lot of people don't know, but there are actual several different types of ADHD, aren't there? Can you tell us about those? Yes. So, when you're typically diagnosed with ADHD, you'll be diagnosed with one of three types normally. Um, so there's a list of symptoms that clinicians will work from, and these symptoms can be divided into two. One list focuses on

inattention. So, that's your classic kind of um not paying attention to detail in a task or getting distracted. The other list focuses on impulsivity and hyperactivity. So that's the kind of always jiggling around or making impulsive decisions um and choices around things you're doing. So when you're diagnosed, you're either diagnosed with a predominantly inattented type, which means the vast majority, if not all of your symptoms are from that inattention list, or the hyperactivity impulsive type, which is the opposite. So where they're all from the other list. And then the actual biggest category um that you find in the diagnostics is a combination of those and that's simply called the combined type and that means you have a roughly

equal mix of both of the types of symptoms. So let's have a look at some of these symptoms then because um like you say in attention there is one of them like an inability to focus but that this is a lot subtler than that would sound isn't it? Yes. And actually the name attention deficit I feel is a little bit of a misnomer really because there can be difficulties sustaining attention and that attention to detail and finishing off tasks. So you start something but you won't necessarily finish it. But actually the flip side of this is extreme focus on things that people are interested in and that's referred to as hyperfocus. So I almost feel like it would be better if the condition had the word dysfunction in it

rather than deficit because dysfunction of course could be too much or too little whereas deficit just implies too little. So the inattention side of it is quite nuanced. People with ADHD can show extreme hyperfocus um on something they're really interested in to the point of forgetting to stop to go to the toilet, to stop to eat, that kind of level of in of hyperfocus um which some report finding very helpful. So what's the kind of threshold for this and if we want a clinical diagnosis? Because I think lots of us are prone to things like daydreaming or losing concentration or forgetting why we left the room and things like that. you know, we all do it. So, when does it become, oh, that's a symptom of ADHD? So, that's a really interesting

question. I think one that at the moment um we perhaps oversimplified in a lot of the popular understanding of ADHD. To reach a clinical threshold, you have to have a certain number of symptoms. The actual number you have depends on whether you're being diagnosed as a child or an adult. But what's critical about it, irrespective of the exact number, is that it has to result in functional impairment. You know, the other day I put my phone somewhere. I couldn't find it and I found it in my underwear drawer. What the hell was it doing in there? That's a ridiculous thing to do. And clearly it was in my hand when I went to put something in the drawer and I put it down to shut the drawer and shut it in there. Is that impairing me? Well,

other than the fact I walked around feeling like a bit of an idiot when I couldn't find it and ringing it and all sorts only to find it in a drawer. That was 10 minutes of my life. It's not a functional impairment. And I think that's the critical thing. We're seeing a lot of people say exactly that. Oh, I'm prone to daydreaming. Um, I like to, you know, I procrastinate. I can't get going with my housework or I can't get going on my course work for ages. That isn't necessarily ADHD. ADHD is something that can be genuinely impairing on a day-to-day basis. Um, and the symptoms are consistent. So, the other thing to think about is even if you're diagnosed as an adult, you should have started displaying symptoms that can be

verified. school reports, parents, older siblings, or your own recollection um from before the age of 12. So, this isn't a late onset in the sense that it doesn't appear late, but you can be diagnosed late. Okay, we can have a look at that in a little bit, but let's stick with the let's move on, I suppose, to the hyperactivity element. So, I think a lot of us can relate to this as well, especially we've only a few years ago come out of the lockdown. And I think you know I don't have ADHD but um during that period when it was difficult to go outside I was getting really restless you know and feeling sort of pent up. And so what's the difference there? How does the hyperactivity manifest?

Well again I think it's important to recognize that there's nothing within the ADHD symptom list that people without ADHD never do. So you can think of them as traits that are on a continuum if you like. Um and I think COVID and the lockdowns were a very unusual period. I mean unprecedented in our lifetime to be restricted on leaving the house and you know the kinds of exercise you could do, how many people you could interact with, that kind of thing. And I think that did result in quite a lot of um frustration and there was obviously anxiety around health and fear and if not your own health, potentially vulnerable relatives. So I think that did create this kind of almost a desperation to get back to normality. Um, and for some

people with ADHD, that was a really difficult period. For others, actually, you hear it both ways. You hear people saying, "Well, actually, it kind of took the pressure off me. I didn't have to mask all day cuz I didn't have to go into the office. I could do my job at home or I could just stay in my own company or those that knew me well and I didn't have to mask." So, I think with the hyperactivity and impulsivity, um, it is again, it's something that anyone can display, but it's when it's displayed to the level of functional impairment. And we also know that um you know that side of ADHD is probably the reason we see some gender differences as well. Um little boys tend

to be hyperactive and impulsive. Little girls tend to stare out the window. So there are subtle differences in how these symptoms are portrayed and as you grow up the hyperactive impulsive symptoms tend to diminish whereas the inattention ones remain. Not for everybody but a general pattern is they tend to reduce. Right? because that's something that I've heard that it typically affects boys more than girls. So I was wondering is there any truth to that or is that due to this sort of bias of you know naughty boys? Yeah. So I think there is a little bit of truth but there's a big bit of bias in there as well. So we know that in childhood um you're going to get around I mean the reports vary quite a lot depending on which studies you look at

but 1:3 1 to four the ratio of girls to boys being diagnosed. So far more boys being diagnosed to girls. Um, and that makes sense because one of the features of ADHD diagnosis is that the symptoms have to be present in one or more setting. So for a child that's typically at home with their family and at school, which means the teacher has to see it. And a teacher has 30 children in a classroom, they are not going to notice the girl sat at the back daydreaming in comparison to the boy rocking back and forth on the chair, putting his hand up, interacting, interrupting. So I think there is a little bit of a bias in the children that come on the radar and the boys tend to come on the radar more

than the girls. By the time you reach adulthood the diagnostic the prevalence rates are almost one to one. So same number of women to men um being diagnosed. The challenge is we're seeing a lot of interactions with female hormones which I think is creating a very muddy picture for diagnosing girls and women which doesn't seem to be the case um with boys and men. So we have got a biased diagnostic criteria I think um but I don't you know it obviously didn't set out to be biased. It's just that much of the research that was conducted that fed into that criteria was conducted on boys not girls. Um, and I think we're now only just starting to understand the possible interaction between the female hormones and um, the ADHD

symptoms in girls, which is meaning that in 10 years time maybe we'll have a clearer picture and a slightly different diagnostic criteria. Interesting. So you mentioned there so the ratio is sort of 1:3 1:4 boys to girls, but how about over the entire population? You know, how do we even know how prevalent ADHD is? Yeah. So in um children, you're probably talking around 6 to 7% of children based on and these are worldwide studies, so not specific to the UK or even um western populations, although they tend to do more research in the western

populations. in adults. Um there's two interesting ways to kind of conceptualize this and both were done in one study. And in the first study they and the first way is they said it's around 3% that have ADHD, but they also said there's around 6% that have symptomatic ADHD. So that doesn't mean they had a diagnosis, but they were showing slightly elevated symptoms. But I think if we go on the ones that are diagnosed around 6 to 7% of children, around 2 to 3% of adults, but numbers are rising, not necessarily because more people have ADHD, but because we're getting better at diagnosing. So let's have a look at that because re over recent years um a lot of people have been in the news you know sort of

well-known people saying you know well I'm 35 and I've only just received an ADHD diagnosis and for some other sort of neurodeivergent um conditions as well. So why how was that being missed and you know how have we found it now? I think there's several reasons. Um, I think sometimes there is a stigma. So even if a parent or the person themselves is aware they feel different, they're they're processing things differently, they might not necessarily feel able to go forward, they might come forward and be completely dismissed um by whoever they go forward to. So they may be dismissed by their GP. Um, a lot of women are diagnosed with depression and anxiety on the way to an ADHD diagnosis. And it's not really clear if

they were the wrong diagnosis or actually these women were depressed and anxious because they had undiagnosed ADHD, but they will often be diagnosed as something else along the way. Um, and I think so, so stigma or misdiagnosis or kind of misdirecting someone could be an issue. I think the other issue is simply that we need a frame of reference. And I think this is really interesting. I went to an event recently with um the parents of somebody who had set up a charity for ADHD. Um they said something really interesting. They said they only had one child and they just thought he was a bit, you know, lively and boisterous and they didn't have a frame of reference. they had

their friends children but of course everybody out for the day on their best behavior they couldn't quite get it and so I think you do need a frame of reference um and there has to be some concern so I think there's there's stigma there's needing a frame of reference and I think the other reason is that you know we can think of the neurodiversity the model paradigm where this is a difference not a disability it becomes a disability when you're in a setting or a context text that makes it a disability. So, it's not intrinsic about the condition. And I always use the example and apologize to any accountants, but I always use the example of accountancy because I imagine

I don't know anything about accountancy, but I imagine it to be quite a dull sit in front of a computer and count numbers job. If you are somebody with ADHD and you end up sitting in front of a computer counting numbers and lots of attention to detail required, not much interaction stimulation coming back to you, you might find that really difficult and you might become aware very early on that there is something different about you. If you decide, for example, again choosing a probably a ter terribly stereotyped example, you decide to become a creative artist or an actor or a musician, it's very creative experience where you can change the roles you're playing and the

approaches you adopt. So you might never get to a point where you feel impaired. So you might not actually come forward for a diagnosis. So I think there's all sorts of factors that mean we are diagnosing people later. Yeah. So you mentioned there anxiety and depression. So does ADHD often tend to coincide with other conditions? Yes. So it's extremely rare to find ADHD completely on its own in anyone. It's actually rarer to find it on its own than it is to find it alongside something else. So it's reasonably commonly found, you know, in up to about 50% of people with ADHD will also have another form of neurodyiversity. Autism is the most common that you find alongside ADHD, but also dyslexia as

well. Um, and then in women, anxiety and depression are the most common forms. In um, boys, you used to see when they are diagnosed as boys, not men, you would occasionally see them um, diagnosed alongside things like conduct disorder and oppositional defiant disorder. So it is very common to see other um conditions that we would either categorize as other neurodiversities or other mental health conditions. But there are also something that people don't really realize often additional physical health conditions that are more frequently found in people with ADHD than people without. So there's co-occurrence with physical health conditions as well. So what sort of physical health conditions? Um so you see lots of stuff

around hypermobility for example um for women they are more at risk of getting various u menstrual related conditions things like endometriosis um see an increase in allergies asthma that sort of thing irrespective of gender so there is quite a lot of um extra things that can exist and interact and intersect with the experience of ADHD which means everybody's experience will be slightly different. Um, also subtler changes that don't that don't have a label. They're not a condition or an illness. Um, but uh GI changes, so how your tummy reacts to certain things. It might be a bit more sensitive. Um, so that's one possibility. Alterations in sensory processing, which we kind of accept because we know that happens with autism and ADHD is another form of

neurodyiversity, but alterations in sensory processing as well. Yeah. So I know a lot of your work has been on sort of non-farmaceutical treatments. So I'd really like to talk about that in a moment. But let's have a look at some of the you know the medicines that are given to people when they are diagnosed with ADHD. Yes. So there's two broad classes that you can have. Um the first is the stimulants and I think these are the ones that most people know about because I suppose they're the most controversial. So that is um in the form of either amphetamine or a formulation of amphetamine or methylenadate. So they're better known by their brand names of things like aderall which is amphetamine or ritin or concertera which

is methylenadate. And those stimulant medications work by altering the amount of particular chemicals in the brain. Um most notably dopamine but they also impact on a second one called noradrenaline and to a much lesser degree serotonin. And so it's not really clear exactly how the drugs work as is often the case in medicine. They were sort of accidentally found to work. Um and we do understand what chemical messengers they act on as their said dopamine predominantly. But exactly why a stimulant should calm somebody down. Yeah. It seems counterintuitive, right? Exactly. And it seems to be that actually it helps regulate. it helps kind of almost um put a rhythm on the brain in a way that it wasn't managing to do by itself. So that seems to be

what happens, but we don't fully understand. Um that's the first class of drugs. The second class of drugs are non-stimulants. So these tend to be given um if somebody can't tolerate a stimulant drug or perhaps they have other health conditions that means they wouldn't be allowed to take one. And um there's now two types of stimulant licensed in the UK but for many years it was just one which was atamoxitine mainly known under its brand name of strata and they work exactly the same way as stimulants but instead of working on dopamine they work on noradrenaline so they increase the amount of neuradrenaline availability in the brain in much the same way the stimulants do for dopamine

and a little bit of noradrenaline. So let's have a look at some other measures that we can take to maybe sort of tamp down the some of the symptoms that people with ADHD experience. And I think a big well a good place to start is exercise. So we all know we should be doing more exercise and it's got all types of benefits for our cardiovascular health and all of the sort other things. But it turns out possibly it can also help with the symptoms of ADHD as well. Yes, absolutely. And I think if we look at all the currently um suggested non-farmacological treatments for ADHD, exercise is the one I'd put my money on.

Um it's got lots of benefits as you say for physical health. And it's not really clear exactly why it works, but then as I said, we're not really clear exactly why stimulants work. But what we do know is exercise will increase dopamine in the brain. We hear people talk about a runner's high. Um, and that is down to dopamine. So, we know it can alter dopamine levels, also alter neurogenine, serotonin. It's just generally a really good thing to do. Um, but exactly why it works with ADHD is a bit unclear, and I think there's probably several reasons. Um, most of which may be completely not specific to ADHD. So we've spoken a lot in our research to people with ADHD who in their own

words use exercise to manage their condition. So we're not doing a trial. We're not asking them to participate. We're asking them about their experiences of exercise. And they talk about using exercise to give them a routine and a structure. So if one of the problems with ADHD is this procrastination, not finishing tasks, not you know, they're using it to allow them to do that. They sometimes also are chasing the kind of reward of exercise. So, you know, chasing that PB when you're running that personal best or training for an event, that sort of thing. So, it can be used to provide a goal and it can be used to provide a routine and structure. It's also likely to help with a lot of the things that happen because you have ADHD. So, I mentioned depression and

anxiety. Exercise definitely helps with those. There's plenty of evidence to support that. There's also reduced quality of life in ADHD, which I think is not necessarily surprising when you see that people with ADHD may have lower educational outcomes, lower lifetime earnings, greater risk of relationship breakdowns, all of those things. Um, and exercise can help with that as well. And one of the critical things which has actually been taken out of the diagnostic criteria used to be in there. So, we're currently on a diagnostic um manual kind of edition five, something we call the DSM5. And back in DSM3, there was emotional dysregulation included in ADHD um diagnosis. It's no longer there, but it

is definitely a feature for many people with ADHD that they struggle with. So, there they struggle with effectively bigger emotions than we might expect for the context. So that can be bigger relation but it can also be much greater rejection or sadness after events and exercise can really help with that. Um not only the actual physical side of exercise but just the kind of you know the repeated automatic almost motions that come with exercise might give people a bit of processing space. So all of those things could be non-specific to ADHD but they help. How about sort of different forms of exercise though? Because there's loads of different ways we can do it. We can go for a walk. We can play a

sport. We can lift weights. We can do things like yoga or pilates. Do they have sort of different effects that we've observed? So that's really good question and I think um there probably are some different effects but what we don't really know exactly what yet. And I think the best way to describe this is when you take a drug um let's say you go to your GPS and you're prescribed an anti-depressant. They might start you on a certain dose and review that dose within a month and if you're responding very well, leave you as is. If you're still not responding as well as hoped, potentially increase it slightly and then eventually reduce it when they can.

The thing about exercises that's that's effectively personalizing your medication, but we don't know how to personalize exercise yet. And this makes perfect sense. You know, if I went into any cafe now after this and I went up and asked everybody on the table how much exercise they do, I'll get somebody that's biggest amount of exercise was walking to that cafe to get a latte and then they're going to walk home. And I'll find somebody else that's training for a marathon or an ultra or playing squash six times a week. So, until we can find a way to personalize, it's really hard to tell.

Um, normally you'd be recommended from a physical health um, standpoint to look at moderate to vigorous exercise. So that's the kind of exercise that gets you out of breath, a circuit class, going for a run, um, something like squash as opposed to going for a gentle walk. Um, but of course weight training, resistance training, they can be very helpful as well. And depending on how you do them, they can also get you out of breath. So we don't really know. there's more to be done in that area to understand. Um, but from talking to people with ADHD, they sort of tend to find something that works for them and stick to it until they get bored of it and then they find something else that works.

How about another thing that's that's gained popularity over the last several years and things like uh meditation and mindfulness, can they help us out here? Yes. And I think um I think they can sometimes interact with types of exercise. Things like yoga of course that tend to be a more mindful exercise um than perhaps some other forms of sport or exercise, but it the evidence looks like they may be beneficial. So as with exercise, even with the medication, this isn't a silver bullet. You know, if you commit to doing um meditation for 20 minutes a day, your ADHD isn't going to disappear. That's that's not going to

happen. Um, but mindfulness practice does seem to help with those peripheral things again. So, it helps with symptoms of anxiety and depression that are often found in those with ADHD. Helps people feel better about their life, increasing quality of life scores, and it definitely helps with emotional regulation. There's some indication it can also help with um the core symptoms, things like inattention. It's worth saying really that actually the core symptoms of ADHD, so the inattention, the hyperactivity, impulsivity, they are really difficult to change. You can't just suddenly, you know, flip a switch and make somebody's attention normal for one of a better word. The stimulants are the best chance of normalizing, and I don't

really like that word, but of normalizing the levels of attention, hyperactivity, and impulsivity. But even stimulants won't actually do that for the majority of people. There'll be some symptoms remaining. So arguably a better approach is not to try and suggest to somebody that well we're you know you go for a run once a week or we give you this medication. Your attention is going to be back to the same as all your neurotypical friends. It's probably better to actually say, let's help you come up with strategies to manage your attention in a way that works for you. And that could be very different depending on, you know, what one person does to another. The strategies could be quite different. But

critically, can we help you feel better about your ADHD and manage some of the things that can be changed like the emotional dysregulation difficulties um and the depression, anxiety that could come alongside the ADHD. So, sort of coming off the back of that then, and I think we generally we are getting better at this sort of thing. That's like making adjustments in the workplace for people that have ADHD and you know, other conditions, you know. So, what can we do there? and how much does that help? There's a real gap in our research understanding of what works in the workplace. And I think that's partly because there's been a very limited amount of research done, but partly as well because what works for one person

with ADHD will not work for another. And when you look at the research literature, what normally happens is somebody says, "I'm neurody divergent. I've got ADHD or I've got autism." and perhaps their line manager or whoever is responsible for adjustment says, "What do you need?" And the person says, "Well, I don't know what I need." Especially if they've only just been diagnosed as an adult, which is quite feasible. I don't know what I need yet. What's available? And then you can sort of go around in a circle of trying things out and realizing things don't don't work or do work. There's no specific thing that will make a real difference.

You know, it's a bit like when you see um some of these buildings that are completely physically accessible. So, you never have to open a door. It senses you coming, the door opens, they're all a good width, there's no stairs. In a way, that's an easy thing to do. Expensive in many cases, but very easy to do. But with something like ADHD, you know, one person might not require any adjustments depending on the nature of their job, but somebody else might require a lot of adjustments and they might not know exactly what they are. You know, having a white noise generator to um kind of drown out the chitchat if you're in an open plan office or being able to wear uh ear protectors or

not working in an open plan office with really bright lighting because you have sensory sensitivities. Can you have a dimmer switch? You know, there could be all sorts of things. Some flexibility on working hours. Um, and it will vary hugely and it will just vary according to the person and their job and any co-occurring conditions they might have. So, how about things like diet? So, I think you know anyone who's been around uh groups of children when they start tearing around inevitably someone will say, "Oh, that child's had too much sugar." Um, and it like that's causing all of the problem.

Yeah. Um, but is there anything is there any link between sort of ADHD symptoms and the food that we're eating? I don't know, sugar, processed foods, lack of fiber. I mean, there could be all sorts of there's not a definitive answer to that question. Again, I think we can be clear that ADHD is not caused by a bad diet. It's not caused by it. Children with ADHD are just like children without ADHD. If you take them to a birthday party and you pump them full of sugar, they're going to run around more. That's that's what children do. When you put that kind of food into them, or probably not just children to be honest, but when you put that food into them, kids run around. So, and that might be

more obvious if a child already has ADHD because they're already hyperactive. So, then they kind of become to the perception of those around them off-the-wall sort of hyperactive. So what we know is that if you have a child that has ADHD and you give them lots and lots of sugar, their symptoms may be worse. But if you don't let them have any sugar, their symptoms won't disappear because their symptoms are not caused by sugar. Um they have looked at various diets from the perspective not of causes but of interventions. Um so as I said, you know, a healthy diet is actually the one that the evidence really supports. So don't ban your child from having sugar

or processed foods. Everything in moderation. They have done some work around something called the few foods diet where you effectively narrow the diet down and then to a few foods and then you reintroduce these foods to see if that um where the symptoms change. That's the diet for which there seems to be the most research done. So in that sense that's got the most evidence for it. But the evidence is not overwhelming. So, it's not like that will solve it. It won't solve it. Um, and omega-3 fish oils are another thing that's that's come up as potentially lacking that could be useful. Um, but again, I think if you have a very if you have a healthy balanced diet, you wouldn't be lacking these. So, sort of by way of summary then,

we've covered an awful lot of stuff there. But, um, and you know, it's quite clear that while we're still learning a lot, there's still a lot more to be learned. So what sort of what are the sort of headline items that we'd like to tackle in the next say 5 10 years regarding ADHD. So I think we do need to look at personalized interventions and I think we need to move away from thinking this person will have a drug and this person will have therapy. We need to look at how we can almost give somebody a basket and they can go around and take what works for them. So yes, I am going to have some stimulant medication. Um, but I'm also going to make sure I exercise and I'm going to have some social skills training because that can be an area

where um, people with ADHD struggle. So, I think we need to look at personalized interventions. That should be a really big area. Um, and I also think we do need to unpick this. I'm going to call it a problem. I think is it's a research problem. The problem of how female hormones interact with ADHD. um because that is half the population that currently we don't really understand very well and we need to get to grips with that. Um so that's really important. Those two things are probably the most important and I think an overarching thing for that is we need to do this with the voices of the people in the research. So, not just would you come into my lab and be my guinea pig and test out this exercise program and

then do an attention test, but actually inviting the ADHD community to tell us what's important. Um, and there are lots of organizations and researchers already doing that, helping us decide the questions that we try and answer and then helping us develop the research and disseminate it when it's done. So, Professor Ellie Dit, thanks so much for joining us. Fascinating stuff. Thank you for having me. Oh, you're welcome. Thank you for watching this episode of Instant Genius, brought to you from the team behind BBC Science Focus. That was Professor Ellie Dummit. If you liked what you just saw, then please do consider subscribing to

the channel and giving this episode a like.