Pharmacological management of attention deficit hyperactivity disorder in adults

[Music] Welcome to the Australian Prescriber Podcast. An independent, no-nonsense podcast for busy health professionals.

Hi, and welcome to this Australian Prescriber Podcast. I'm Dr Justin Coleman, a GP at Inala Indigenous Health in Brisbane. And with me today, I have a fellow Queenslander, Professor Shuichi Suetani, who works at the Institute for Urban Indigenous Health in Brisbane, amongst his other hats. Welcome, Shuichi.

Well, thank you so much for having me, Justin. It's such a privilege to be here.

Wonderful. We're talking today about the pharmacological management of ADHD [attention deficit hyperactivity disorder] in adults, which you were mentioning to me, Shuichi, was not really much of a thing when you trained in medical school, but has now become a majority of your current psychiatric practices.

That's exactly right, Justin. I would even say when I started training in psychiatry 10 years ago, as an adult psychiatrist, I never had any formal training in ADHD. But in the last 5 years, like most listeners, I suspect, everyone is talking about ADHD and probably 80% of my patients are coming in with ADHD-related concerns.

I'm very glad you're a quick learner, Shuichi. At the start of your article, which is in Australian Prescriber, you do state that ADHD affects around 3 to 5% of adults. As I often caution with these podcasts, the prevalence studies tend to cast a wide net, whereas the therapeutic intervention studies are usually not done on the 3 to 5%. They're far more likely to be done on the most severe 1%.

So, the therapeutic interventions don't necessarily apply to the entire 5% if you have wide diagnostic criteria. I only mentioned that as a caution because, of course, every GP and pharmacist would be seeing in the last couple of years, a very large increase in people who have ADHD or who may have ADHD and are looking for treatment. Talking of which, so someone comes into your practice and they may have symptoms of ADHD, I was wondering if you could talk us through the initial psychiatric assessment that you would make and whether you do this quickly or over a period of time.

Yeah. I think that's a really good question and a very timely one in Queensland, given that since December last year, GPs can now diagnose and treat ADHD in adults. And I suspect that a lot of other states and territories will do the same in coming time. I think if there's one take-home message in terms of assessment of ADHD, that would be there's nothing special about ADHD as such.

And the really important thing not to fall into is that thing about if you've got a hammer, everything looks like a nail. So if you go in thinking we are assessing ADHD, you probably are going to find ADHD. And that's just the nature of how diagnostic criteria in psychiatry are written. We wrote in the paper something like 17 different psychiatric diagnoses have inattentiveness as one of the main features for the condition, and I think it's number 3 in the DSM [Diagnostic and Statistical Manual of Mental Disorders] list of most common conditions.

And if you think about number one, difficulty sleeping. Again, people's ADHD come with symptoms like that. When someone asks you, 'Do I have ADHD?' the psychiatric assessment is all about making sure that you're looking at other things that may cause the symptoms. Some studies will tell you about 80% of people with ADHD will have some kind of a comorbid psychiatric condition in addition to ADHD. So, it's a huge number.

In my clinical practice, I can honestly say that it's very unusual for me to see an adult with just ADHD, straightforward ADHD. So it's always good to assume that there's something else going on when someone comes in requesting ADHD assessment.

I think that is sage advice. I recently did a podcast on childhood ADHD and I'm interested in your take on how adults differ. You've mentioned the first one is that there's much more likely to be other things going on, and that can be often in a negative way in the sense that they may have substance issues or various other mental health diagnoses, and I guess a physical way in that their bodies are older, their cardiovascular systems are older.

And another way they differ, you point out in the article is that a lot of adults will have had time to develop strategies, either at home or at work, in order to try to deal with their symptoms, and they have more chance at modifying their life accordingly than children have.

Yeah, and I think your brain matures as you get older. The comorbidities are interesting ones because for kids, you're probably looking at things like learning difficulties or intellectual impairment or autistic spectrum disorder. Whereas I think for adults, we probably don't look at those things as much as paediatrician would do, but I'll be thinking more about anxiety, depression.

So physical conditions, things like anaemia and low hypothyroidism, easily reversible causes of inattention. I also think obstructive sleep apnoea is something that gets missed quite a bit, especially people who are kind of middle-aged and up. And what we meant by people learning to adjust to their challenges better is even though we kind of think of ADHD as a brain disorder, the environment you are in impacts your behaviour so much. And it's much like any other mental illness.

I start seeing people, probably aged 15 or 16 when they go out of paediatric care. And I often see young people who come to me doing really well, but then leave school when he's, let's say 16, gets into some kind of trade work where there's a structure, but not in the same way, classroom structure, school and stuff like that. And the function disappears because the environment's changed and some of them may decide to stop taking medication because they don't need to because they can focus on what they want to do at the times that they want.

You're not really just looking at the symptoms here. You're looking at the impairment the symptoms cause. And in adults, there's a lot more flexibility in terms of how you cope with the environment to manage the behaviour.

I am always fascinated by that background to any of these conditions that we talk about in Australian Prescriber. So you've mentioned some of the things we look for, anaemia and thyroid, and essentially cardiovascular health, which takes into account blood pressure, heart rate, and liver, kidney, cardiometabolic status.

For those we're considering putting on medication, what sort of cardiovascular risks are we particularly concerned about?

There's clear guidelines from the Bi-national ADHD Association in terms of when to refer to cardiologists, and I think it's really handy. So we know that at least in the short-term when we put people on most ADHD medications, except for maybe guanfacine, your blood pressure and your heart rates will go up.

And at the populational-level, it doesn't look like clinically, a significant increase, but I'm sure in individuals, you will get people whose blood pressure will go up and that might concern you. I think we just need to be mindful that when we talk about evidence in ADHD, often we are mixing up different age groups. So someone in the 40s might have different risk profile compared to a 5-year-old who gets started on psychostimulant medication.

The specific cardiac examples that the guidelines suggest are things like actual active cardiac symptoms, like shortness of breath, fainting, palpitation, chest pain, and also heart murmur. Mainly, you're worried about things like QTc prolongation and make sure that there's no undetected cardiac structural abnormalities. And I think I'm a psychiatrist, Justin, so I'll probably have a very low threshold getting cardiology input.

I think otherwise a good GP with a stethoscope is an alternative sometimes. Yes.

I'm very mindful that GPs probably feel a lot more comfortable dealing with the cardiac side effects of ADHD medications than we do.

Sure.

The other thing that we worry about is the appetite suppressant side effect of psychostimulant medication and atomoxetine to some extent. For adults, I don't actually worry about it as much because most people, when I talk about this side effect of, 'Oh, you might lose weight,' people are actually quite happy about it. So again, it's not like kids where you have to worry about the height and all that kind of stuff.

I also tell people about the risk of seizure. I think the evidence is a little bit mixed, but again, just as information, there's a chance that it might lower your seizure threshold. If anything like that happens, stop the medication straightaway and let us know, that kind of stuff. Your heart, your seizure risk, and your appetite are the 3 main things that I always talk to my adult patients about before starting medication.

So Shuichi, just moving from where you're perhaps less comfortable, which is the things at the other end of the stethoscope to where you're very comfortable, pharmacology itself, could you briefly run us through the psychostimulants and the non-psychostimulants for ADHD?

Yep. It's pretty simple because you've only got really, 4 medications that you're playing with.

Yep.

So the way that I think about it is you've got 2 different types of ADHD medications. So you've got psychostimulants and non-psychostimulants. Psychostimulants gets divided into 2 different subtypes, methylphenidate and amphetamines.

So methylphenidate, I'm going to use the trade name just because that's how the different formulations are structured. So you've got your short-acting (SA) formulation, Ritalin SA is the main one that we use. For the long-acting methylphenidate, you've got your Concerta and Ritalin LA [long-acting]. It's something like Ritalin LA is 50-50 short-acting and long-acting, and Concerta's something like 75-25 long-acting, short-acting. So Concerta actually lasts a little bit longer in the system.

With amphetamines, you've got the short-acting ones, your dexamfetamine, and the long-acting one is your lisdexamfetamine, which is Vyvanse is the trade name for that. In terms of non-psychostimulant medications, we've got options like atomoxetine and guanfacine, and sometimes clonidine gets used as well. But I think in practice for adults, we often end up using atomoxetine as a non-stimulant choice for ADHD pharmacological treatment for adults.

So in practice, psychostimulants seem to have better evidence for efficacy. So if there's no contraindication or no concerns about any particular medication, I usually start with the psychostimulants, so either Vyvanse, Ritalin (or methylphenidate). And if that doesn't work, I'll try other psychostimulants, so that'll be step 2. And if that doesn't work, you can always go for non-psychostimulants. And in practice, the majority of time, I end up using atomoxetine as a number 3 choice for most people.

Thank you. And in terms of side effects to watch out for, I think we've covered the blood pressure going up and the pulse rate going up, and we need to keep an eye on the cardiovascular side. Also, it does increase the risk of serotonin syndrome if combined with other medication.

Yeah. I think serotonin syndrome is something that most psychiatrists are overcautious about because we probably have seen the cases where things have gone quite bad. But again, going back to a lot of comorbidities, most of these patients probably would be on some kind of other antidepressant medications or psychotropic medications even before they come and see you for ADHD treatment.

And I find that for most people, you need to be mindful of coexisting antidepressant medication such as SSRIs [selective serotonin reuptake inhibitors] and SNRIs [serotonin noradrenaline reuptake inhibitors], but most people can use ADHD medication quite safely as long as you monitor for symptoms and side effects, and start low and go slow. Like anything else, if you've got other medications in place already, just take your time, starting, going up slowly.

Sure. And I guess being aware of other substances as well, both licit and illicit, so alcohol and opioids, cannabis, and various other substances. We won't go on about it, but we do also need to keep an eye out for misuse of the stimulants.

Yes. Sometimes ADHD medications, especially psychostimulants can increase your risk of psychosis, especially when used with illicit substance. So it's important to be mindful of people using other things as well.

Okay. So the patient has been started on an ADHD medication. We need to see how they're responding. Like so many conditions, we see them often, early on. And then if they're stable, we don't have to keep such a close eye. You mentioned there's an adult ADHD self-report scale which can be helpful.

Yeah. I find that screening for ADHD is probably not a very useful use of your time because everyone just comes up with high symptoms anyway. But if you keep doing the same screening tool over time, sometimes you see the benefit of the changes in the symptoms over time. And that's quite a useful way of checking how things are going, the response to the medication that you're using.

Yes. And at the same time, we're looking at first, side effects and I think we've covered the cardiovascular ones. So we'll look at their heart rate, BP [blood pressure], look at their weight. You mentioned the appetite suppression. And I guess, some psychiatric-type symptoms, anxiety, sleep disturbance, and you certainly mentioned psychosis. They're the sorts of things you look out for in terms of once you start the medication?

Yeah. And you're just looking at the benefits, side effects, both physical and psychiatric. It's always useful to check about compliance in terms of missed doses. Some people decide not to take things on the weekends, and given that psychostimulants are controlled medication, you'll always be checking and making sure that people are getting benefits from the treatment that we're providing.

And if the patient doesn't seem to be getting any better, you mentioned adherence, obviously is one factor. What other factors can there be if nothing seems to be changing?

I think it's always important to remind yourself in psychiatry, diagnosis is always provisional or it's always a working diagnosis. Especially for something like ADHD in adulthood where the symptom clusters are so nonspecific and comorbidities are so common, you need to always go back and say, 'Okay, is this person not getting better because we're not treating the right things?'

So always think about if the diagnosis is correct or not. If someone's not responding well, that's probably the first thing that I think about in terms of where to go from there.

In terms of the long-term benefits of ADHD medication, I know for opioids in chronic pain, most of the studies are showing benefit in the first 6 weeks and up to 12 weeks, and there's actually very little evidence that it makes a whole lot of difference in the longer term.

ADHD drugs in adults have been less studied, and there have been far fewer years to study. Where do we stand in terms of the long-term efficacy and effect on one's life and symptoms?

Yeah. I think that's a really good question because when I started learning about ADHD, which would've been only 5 years ago, that was one of the striking things about ADHD medications. These medications that have been run for long, long time, and our paediatric colleagues have been using it for years and years, but I think we don't always remember that this big wave of adults, people who are older than 18 using medication consistently is probably something new that hasn't really happened before.

So as such, we don't really have a good body of evidence for long-term effect, especially for older people. So for example, using psychostimulants starting from 5 until you're 75 is going to be quite different from starting amphetamine when you're 45, for example. So we don't really know the evidence.

I think in setting like this, you always go back to, okay, what are the benefits? What are the side effects? Are there non-pharmacological changes that people can make that's going to make things better? And like I said, ADHD is not just about symptoms, it's the environment that's important. The impairment comes from the environment that you live in as much as the symptoms that you're experiencing.

We're almost out of time. Professor Shuichi Suetani, what are your top tips? What do you tell patients when you start the medication? Any hints that you give them before they walk out the door?

I think there's a lot of positive placebo effect to ADHD medications, where people come in with a lot of expectation that it's going to change their lives. The funny thing is a lot of people tell me that it's been a life-changing thing, getting diagnosed and treated for ADHD. Even though the data is reasonably short term, it's a very effective medication for ADHD.

But what I try to explain to people is pills don't teach skills. It is something that's going to help you. It's going to give you an opportunity to do things that you might not have been able to do because of ADHD symptoms, but that's your starting point. And what I often say is medication becoming almost like a silver bullet.

So we just need to make sure that even though it's a very effective intervention, it should always be one part of a wide range of changes that you make in your life to treat symptoms of ADHD. And medication's not going to fix everything, but it's going to give you an opportunity to make changes that's going to make your life better.

Professor Shuichi Suetani, on that note of philosophical advice for our patients, I thank you for joining us on today's podcast.

Thank you so much, Justin.

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Shuichi Suetani received honoraria from Sage Publishing, Inside Practice Psychiatry and groupH. He also received advisory fees from Seqirus in relation to cariprazine.