Transcript
Dr Blandine French David, in terms of parenting intervention, when you talked about the outcomes of it, you mentioned that people who don’t take part in the intervention do not report many changes, such as Teachers, for example. So, if other people cannot see the changes in the children, then does it really work?
Dr David Daley It’s actually quite difficult to answer that question, because unhelpfully, the answer is we don’t know. So, what I was referring to there was a number of findings from meta-analyses, and so meta-analyses are where people look across the outcomes of lots of different studies and they, kind of, average out the findings to get – to, kind of, get the average picture. And in meta-analyses, when you look at the impact of behavioural interventions on ADHD symptom reduction, the people who attend the intervention, which is usually the parents, report that they are effective, and the effect sizes are generally about .4. And people who are probably blinded to interventions, so those who don’t engage in the intervention, and who haven’t been told the child’s treatment allocation, so whether the child was in the intervention arm or the control arm, they generally don’t see anything at all. The effect size is – can be as low as 0.02, which may as well be zero.
There are lots of possible explanations for this. The most obvious one is that if you’re comparing Teachers again – Teachers ratings’ against parents’ ratings, well, Teachers see children in very different environments to the parents. So, Teachers generally see ADHD children in very structured environments and parents see children in less structured environments, ‘cause the child’s relaxing at home. So, that’s one possibility, that it’s just different contexts that confuse the rater.
There are lots of other problems with this methodology. Quite often in trials, even if you’re taking a Teacher rating, it’s not the same Teacher before and afterwards. So, that also doesn’t help, it adds extra noise, because we know from the literature that have looked at how, you know, two Teachers teaching the one child, so Teachers that might do a job share, for instance, they wouldn’t necessarily rate the child’s behaviour the same either. So, there are lots of methodological problems that might confuse the situation and make it harder for us to work out what’s actually going on.
What is interesting from those meta-analyses is that when you look at conduct problems, there is a much higher level of agreement. So, for conduct problems, the person who comes to the intervention, which is usually the parent, says, “Yes, you know, they help reduce conduct problems,” and the effect sizes are between .3 and .4. And there, the probably blinded informants, again, who are usually Teachers, do see change in the child’s behaviour.
Now, another possibility is that in this meta-analytic work, we only look at the differences between these two types of raters before and after intervention, and if you were to look at it in the longer term, perhaps those probably blinded informants would begin – would see change in ADHD symptoms. So, it may be, for instance, that in these interventions, conduct type problems respond much more quickly to the parents’ use of strategies and ADHD type problems take longer for the child to respond.
I’ve always been of two minds about what this data actually tells us. So, as a Scientist, I want to absolutely make sure that we double check and verify every finding. That’s part of my scientific training. But clinically, especially these days here in the UK, we almost entirely rely on parents’ reports for everything, including assessment and diagnosis. So, the Clinician part of me is a little less worried that we don’t get independent corroboration of the success of the intervention, whereas the Scientist part of me remains concerned.
Dr Blandine French And in terms of long-term impacts, you mentioned there is very little longitudinal data on the effect of parenting intervention, but what do we know in terms of, you know, the long-term changes? Do we notice changing – you know, what does the data say, does it show changes a year down the line, two years down the line, five years? You know, how long do these kind of changes or improvement in the child’s improvement last? What do we know?
Dr David Daley Very little, unfortunately. So, most trial designs would look at – would compare the impact of intervention over some form of control. In the last five or ten years, that control is usually treatment as usual. Going back a little further back in the literature, it was quite often wait-list control. But we’d normally look at the effects of intervention over control before the start of intervention, at the end of intervention and at a follow-up point, that could be anywhere between four weeks and 24 weeks. There are very few studies that have gone beyond 24 weeks. I can only think of one or two in the entire literature that have gone as far as 52 weeks or a year, and virtually nothing later than that.
And one of the problems with this evidence base is that in those early trials, where you were comparing intervention to wait-list, as soon as you finished the trial, you offered the intervention to those on the wait-list. So, that then meant you couldn’t follow them up anymore because everyone had had intervention, and the only difference between the two groups was the time at which they’d had the intervention. When you then do trials that look at comparing intervention to treatment as usual, then usually those trials show that the intervention is more positive than treatment as usual, and so, the intervention then gets adopted as treatment as usual, which then makes it harder to follow all these children up, as well. So, there are lots of limitations to our understanding, and we honestly know very little about the long, long-term impact of these interventions.
I’ve recently been involved in a really large trial of an intervention called the New Forest Parenting Program in Denmark, that we completed in 2018. We – because we conducted the trial in Denmark, in Denmark every bit of clinical information for children gets put onto these national research registers, called the Danish Registers, and so we will have the opportunity to follow these children up naturalistically in the future using the Danish Registers. And that may allow us to say something helpful about whether these interventions are more effective in the longer term or not, but for now, the jury really is out. Dr Blandine French And in terms of behaviour, as I understand it, the parenting strategies work with certain difficulties of behaviour, but do we see a transfer across other behaviours? So, if we are trying to work with recruiting attention, for example, and we’re working on the attention, do we see any changes in loads of different aspect of attention, such as, concentration, or things like that?
Dr David Daley So, when you look at the evidence base for evaluation of these behavioural interventions, then you certainly do see that these interventions, they target parents’ parenting style or parenting practices. We certainly know that you see changes in parents’ parenting style. So, the meta-analyses very clearly show that receipt of these interventions reduce your negative parenting practices and increase your positive parenting practices. And you see effect sizes of, you know, .7, .8, and those effect sizes are about the same magnitude of change that you get from medication on ADHD children’s symptom reduction. So, they’re very large effect size changes.
So, we know that these interventions change parenting, and when we look at child outcomes, we know that they do change aspects of the child’s ADHD symptom profile. So, we see improvements in attention, you see reductions in impulsivity and reductions in hyperactivity for younger children, but crucially, it’s mostly done by parent report. So, in the trials, where very sensibly Researchers have added in tests of attention, so, computerised tests of attention, or computerised measures of impulsivity, or observational measures of impulsive behaviour in children, they usually don’t see significant changes in those – what we would call those “objective tests.” And the reason for that is that when parents report them on questionnaires, they tend to be talking – they tend to report at a very global level. So, “Over the last three months,” you “know, has your child’s impulsive behaviours reduced?” And the parents think about it, and they think, actually, you know what, in the last three months they have, they been a lot less impulsive. Whereas in those trials, with those objective measures, tests or observations, they’re quite often focusing on impulsive behaviours for maybe ten or 15 minutes in a testing room in some strange university building, where the child isn’t necessarily comfortable or being themselves.
So, there are also lots of methodological challenges that limit our ability to accurately and ecologically capture objective change in some of those core ADHD behaviours. But certainly when you talk to parents, these interventions do change multiple aspects of the child’s ADHD symptoms, but, also, other important aspects. So, they reduced conduct problems, they increase peer relationships, and that’s very important, because quite often, ADHD children struggle to make friends. So, we know these interventions actually help these children increase their peer group, and that’s very important.
And there’s some evidence that they can be beneficial in terms of increasing academic attainment, but the measures for that are often quite messy. So, for instance, we’ve never had a trial that’s looked at whether the child’s – here in the UK, whet – that’s increased the child’s scores at their SATs, for instance. So, when I say they increase academic ability, they increase estimates of academic ability that research trials take, such as, you know, reading level, for instance.
Dr Blandine French Thank you. So, these resource that you describe, are they the same across all different party interventions, or are there some differences between the type of intervention that you do? Dr David Daley So, generally, funders are not too keen in funding large, expensive trials that compare two psychological interventions head-to-head. I can only think of two trials that have actually done that. So, one was conducted in the United States, and it compared the New Forest Parenting Program to Helping the Noncompliant Child, for pre-school children, and it generally found that both interventions were effective, but one intervention wasn’t better than the other, but both of them were better than wait-list control, across a range of different outcomes.
There was a second trial that was done here in the UK that compared the New Forest Parenting Program to the Incredible Years Programme, again, for pre-school children. In this trial, there is an added complication because the New Forest Parenting Program is an individual home-based programme and Incredible Years is a group-based programme. So, that was actually a really messy trial, wonderfully pragmatic, but very messy. And again, there wasn’t a – there wasn’t clear evidence that one intervention was better than the other. There were some very small trends, but they were very difficult to interpret.
The interesting thing that came out of that trial was the health economic evaluation, that showed that the individual home-based programme, New Forest Program, was actually cheaper to deliver than Incredible Years, the group-based programme. And that was surprising, because most people had assumed that group delivery is cheaper than individual, but in that trial, that turned out not to the case. Because when you’re delivering a group-based intervention for parents of children with ADHD, who are often quite busy and chaotic, if a parent doesn’t come to the group, you have to try and catch up with that parent some stage during that week, to share the information with them that they missed in the group. So, that when they come back to the group next week, they’re not at a disadvantage.
And so, for behavioural interventions delivered in a group format for parents of children with ADHD, you often end up running both an individual programme and a group programme in parallel, and so, it’s actually cheaper just to scrap the group, and deliver an individual programme, where week on week, you can vary the day and the time that you meet the parent, to, kind of, meet their needs. Dr Blandine French So, you mentioned the Incredible Years, and the New Forest Parenting Program, what are the names of the most common and successful intervention? If I wanted to implement them in my practice, what do I need to look for?
Dr David Daley I think different people are looking for different things. You should – as a Clinician, you should be seeking to implement evidence-based interventions, although a lot of Clinicians do struggle to understand exactly what makes an evidence-based intervention. The New Forest Parenting Program, for instance, I think, has at least eight positive randomised controlled trials around the world, including three or four here in the UK. Some other interventions only have one positive randomised controlled trial. And so, there are – there’s no accepted understanding of exactly what is an evidence-based intervention, but there should be at least some evidence, some strong research evidence, that the intervention is going to be effective for the problem that you want to address and for the people that you’re trying to support.
And then it’s more about availability. So, for instance, I mentioned Helping the Noncompliant Child, which was one of the two interventions in that head-to-head trial run in the United States. I don’t think it’s possible to access training in Helping the Noncompliant Child here in the UK, at the moment. So, once you choose an intervention that is evidence-based, the next question is, is it possible for me to access training and access supervision while I practice delivery? And certainly, for the New Forest Parenting Program, Incredible Years Programme and Triple P, I am aware that it is possible to access training and supervision here in the UK, and, also, generally, all of those interventions are more widely available internationally, as well.
So, once you’ve thought about evidence-based and whether I can actually access training or not, you then get down to the pragmatics of how long are those interventions? So, Incredible Years is a group-based intervention, Triple P is – can be either individual or group, and New Forest can be individual or group, as well, but it’s usually delivered as an individual programme. And then the last thing is how long does it take to deliver these interventions? So, there’s actually quite a wide variation in the duration of some of these interventions. So, when Incredible Years is delivered for conduct problems, it’s usually delivered as a 13-session group programme, but when it was trialled for ADHD, they increased it to 20 to 22 sessions. So, if you want to use Incredible Years as an evidence-based intervention for chil – for parents of children with ADHD, you need to be willing to deliver 20 to 22 sessions, which is quite a lot. 20 to 22 weeks doesn’t fit into any time in the year. You can’t do it between September and Christmas, or New Year and Easter, and it’s – that’s quite a lot of commitment, both from the parents and the Therapists.
The New Forest Parenting Program, on the other hand, is eight one-hour sessions. So, it is a lot – it’s a briefer, and it’s more focused, and for some Therapists, they know that it’s harder to get much more extensive longer interventions commissioned in their local areas. So, they may be better off going for something that is still very evidence-based, but is a shorter commitment, and therefore, Clinicians are able to treat more families with the available time and resources.
Dr Blandine French And in terms of delivery, you mentioned that one-on-one reduces bias to taking part in intervention and is somewhat cheaper, but what about outcomes? Is there any evidence that group delivery versus one-on-one have better outcomes, one way or another? Dr David Daley There’s nothing conclusive that would allow me to answer that question, the evidence doesn’t exist. The small number of studies that have looked at head-to-head comparisons have not shown any definitive advantage of one intervention over another, so it’s down to preference. We do need to remember that lots of parents are looking for individual intervention, but not all. Some parents would rather be in a group, for various reasons.
When I deliver behavioural interventions, I like to do it individually and I like to do it at home. I feel there’s an enormous clinical advantage to actually seeing the environment you’re trying to modify. It’s really, really helpful to go and visit the parents at home, and you get an idea of what home life might be like for the child you’re trying to help. So, is the home environment really cluttered and chaotic, or is it incredibly clean and tidy, in a way that my house would never be? And it gives you an idea of what family life will be – is like for that child, in a way that you can never get from meeting the parents, either individually or in group, in the clinic.
Dr Blandine French So, are interventions alone enough, or is it better to mix with medication, for example? Dr David Daley Okay, so certainly here in the UK, Clinicians should be guided by the recommendations from NICE. So, most Clinicians will be aware that it’s rare to offer medication to children under the age of six, because there’s very few trials that have looked at the efficacy of medication in younger children. And the small number of trials that have done that, in places like the United States, tend to report smaller effect sizes and much higher rates of side effects or adverse events in the use of ADHD medication in younger children. So, for younger children, we should be offering behavioural interventions as a first offer. For older children, I think the evidence internationally is that combined intervention is best. So, adding in both medication, which can have a rapid effect on the child’s symptoms, and then, also, making sure that parents are offered access to a behavioural intervention, as well.
I think what’s really important to remember is that when we look at the evidence base from many evaluations of ADHD medications, they’re very good at targeting core ADHD symptoms, such as inattention or impulsivity, but they’re less good at targeting other outcomes that are really important for the child and important for the parent, such as, helping the child do better at school, helping the child make more friends. And so, for that reason, as well, it’s important to combine these interventions together, to use both medication and behavioural interventions, so that we’re offering a more global solution for the myriad of difficulties that ADHD cause for the child.
Dr Blandine French And in terms of psychological intervention, you talked a little bit about cognitive training. Can you explain to us what cognitive training is? Dr David Daley Sure. So, cognitive training is all about training aspects of the child’s executive functioning. So, we know from research trials that a lot of children with ADHD have difficulties with executive functioning. Not all children with ADHD have difficulties, but lots of children with ADHD have difficulties with executive functioning. So, for instance, they may have difficulties planning or organisation, or working memory, or inhibitory control. And cognitive training is all – is about finding innovative ways to practice these aspects of executive functioning. So, it’s usually computer type games that children can do again and again and again, that would practice aspects of executive functioning.
And until recently, there was very little evidence that cognitive training impacted on core ADHD symptoms. So, there’s a lot of evidence, going back at least 20 years, for what we call near transfer. So, if you practice inhibitory control, you might see that the child’s working memory system gets a little bit better. So, near transfer from one aspect of cognitive training to another. But what’s been lacking is any evidence of far transfer from practising working memory to actually reductions in AD – to improvements in ADHD symptoms, and that evidence is beginning to change a little bit.
So, until recently, the literature was saying, “Actually, cognitive training doesn’t really work, at all,” but now there may be some suggestions that there may be some limited benefits in terms of ADHD symptom improvement from cognitive training. The challenge, as always, is that it’s quite hard to do. You – the child has to do a lot of it, and although they’re presented as computer type games, they’re often not very enjoyable or entertaining, and so, often, parents struggle to get children to do the cognitive training in a – in as intensive a way as is necessary in order for the child to see the benefits.
Dr Blandine French So, we mentioned cognitive training, neurofeedback and we discussed about parenting intervention. Is there any other forms of non-pharmaceutical intervention that we haven’t mentioned yet? Dr David Daley There’s no other core psychological intervention that we haven’t mentioned. There are other forms of intervention that have some evidence for ADHD, but most of them would be dietary, so they wouldn’t be psychological interventions.