Transcript
Professor Andrew Lewis Okay, I’m Andrew Lewis, and I’m a Clinical Psychologist and Academic working at Federation University in Victoria, Australia. I’ll be doing a presentation today on “The Prevention of Adolescent Depression.” So, before I do so, I just wanted to acknowledge the traditional custodians of the lands and waters where our – my university and myself are located and recognise the continuity of their cultures and caring responsibilities for these sites of teaching and learning, and I also wanted to pay my respect to their Elders past and present.
So, I’m going to break my talk down into four separate parts. First of all, we’ll talk a little bit about what depression is, as it presents itself in adolescents, and we’ll talk about some of the epidemiological studies that tell us more information about the nature of depression in this period, how it presents itself and how prevalent it is in different countries. And then, I’ll move onto what we know about the causes of depression in adolescents. It’s important to have that, sort of, background before we move on to talking about interventions and prevention, because such interventions do need to be targeted at what’s causing the problem. And then, in the final section, I’ll talk a little bit about the work that I’ve done around prevention and some of the studies, intervention, the models that we’ve developed and evaluated, and most of that work has been working with families an – who have adolescents.
So, let me start off, then, with some discussion of the epidemiology of adolescent depression. One of the interesting things about depression is that the prevalence in young children is relatively low. So, some studies, for instance, have found that prevalence estimates are around 2% in children, but move up quite quickly once you move into the adolescent period, doubling, or in many cases tripling, in their prevalence. So too, the male to female ratio, which is one-to-one during childhood, starts to flip around during adolescence and we find a much greater prevalence of females developing depression as compared to males. So, by the time of 18-years-of-age, the cumulative incidence is somewhere around 20% and that’s a figure which is a little bit dated nowadays, and you’ll see me going on to presenting some more current data, which suggests that that cumulative incidence rate is now considerably higher.
Now, the lifetime prevalence of major depression in females has a higher prevalence rate. It actually has its origins in this adolescent period, where the incidence for females tends to, sort of, be double or triple the incidence for males. And so, females unfortunately, carry this lifetime higher degree of susceptibility to depression.
Now, I’ve been, sort of, speaking loosely, using the term ‘depression’, but I think it’s important to try and be more specific. Sometimes we can make a useful distinction between depressive symptoms and psychiatric disorders that have depression as a component. So, this figure on this slide is really depicting the fact that depressive symptoms are a feature of many different psychiatric disorders, major depressive disorder being one of those. But someone can present with depressive symptoms, but the underlying problem might be something more like, say, bipolar disorder, dysthymic disorder, schizoaffective disorder or seasonal affective disorder. All of those disorders have depressive features as a component of them.
So, what are the specific features, then, of depressive disorders? So, here you’ll see an instrument that’s used quite widely in population level studies. This is called a Short Moods and Feelings Questionnaire, and it gives you a rough idea of the kinds of things that people are rating when they’re indicating that they are experiencing a high level of, in this case, symptomatology. So, this is not a diagnostic measure by any way, shape or form. It’s really just a way of a person self-reporting these kinds of symptoms, and as you can see if you read the sections in red here on this slide, that a depressive disorder, it, kind of – it more or less clusters into certain features.
So, there’s one feature that could be called anhedonia and that is, you know, the difficulty of experiencing pleasure. There’s a number of things there that you can see, “I didn’t enjoy anything anymore.” “I felt miserable,” and so on. So, that, sort of, lack of enjoyment of things or losing interest in things. The other component is this self-critical aspect of depression, so someone has a very negative view of themselves, of their place in the world, thinking of themselves as unlovable and no good or a bad person. And this crosses over with a general negative set of cognitions and a very negative view of their experience.
So, the other feature that’s very important to note around depression is that it’s a combination of both, sort of, psychological and mental phenomena and somatic, physical components. So, the physical component is really important to consider and for Clinicians to assess, obviously, so restlessness, feeling tired, and changes in sleep and appetite. So, there’s obviously a biological process, there’s a psychological process.
The final item is, you know, incredibly important from a clinical point of view, that suicidality, thoughts of suicide, are a common feature of someone experiencing depression. So, that should be assessed and interventions undertaken to address that, obviously. Now, as I mentioned previously, there is evidence that there is increasing prevalence in general of mental health problems in adolescents. And just as I was preparing this talk, there was a new paper released from a group that works here in Melbourne, at an organisation called Orygen, and they have released a paper in The Lancet, as a commissioned study on youth mental health. And this is a – some of the data that they presented there of a range of studies, which if you look at the dates here along the X axis, you can see that over a period of – it varies, you know, but generally between about, you know, ten to 15 years ago, you can see that there’s really quite marked increases across a wide range of studies in the prevalence of mental health problems for adolescents. So, the timeframe here is really important to bear in mind. This is a relatively short period of time, and you have this quite sharp increase in the prevalence of mental health problems for both young men and for young women.
Okay, so let’s move on, then, to the second section of my presentation, which is really to try to drill into this a little bit more and understand what are some of the causes of adolescent depression? What do we know about it at this point in time? And the first place to start is to really examine the epidemiological findings in a little bit more detail and scrutinise, you know, what these might actually mean. So, say, for example, if we just take that last slide where you can see that there is an increase in prevalence over the last ten or 15 years in this Lancet Commission report, I mean, this obviously suggests that we’re talking about something that has significant social and cultural factors at play. Human biology doesn’t change that much in that period of time.
So, we know that this very incre – very marked increase that’s occurred suddenly, it must be to do with, you know, broadly what we could call sociocultural or socioeconomic factors. But we also know that the increased – the marked increase in incidence of depressive disorders over adolescence is very closely related to pubertal development. So, that’s this, sort of, underlying biological change that occurs in individuals. We know that as puberty progresses, the further someone moves through puberty, the more – the higher the rate of depressive symptomatology that tends to be reported.
There are significant gender differences, which I mentioned previously, but they are not universal. So, generally, it’s the case that this higher incidence for females is typically in Western countries. So, we also have adolescent-onset of depression being a major risk factor for subsequent episodes of depression. So, this is – this refers to the fact that in its most typical presentation, depression is an episodic phenomenon. So it has a certain course and then, remits and – however, you tend to find that people who experience a depressive episode in adolescence are more susceptible to a repeated episode later on in their life.
Okay, now, more than half of the first episodes of depression occur in adolescence. So, you can see from that further analysis of some of these epidemiological findings, it points very strongly to the need to both understand the onset of depression in adolescents, first of all, and then to think very seriously about interventions that are effective in adolescents and interventions which are going to prevent or reduce the first onset. And so, that’s really the rationale in my, sort of, research focus for focusing my work on adolescents. It makes a lot of sense, I think, to do so.
We know that the world of adolescents is changing very rapidly, and one only needs to bring to mind some of these major global issues, such as climate change and globalisation, economic inequality, the rapid rise of largely unregulated social media and political instability, not to mention, of course, the global pandemic in itself. So, these are things that our – this generation of adolescents are facing. A very complex, unpredictable world. A world in which they are often, sort of, economically disadvantaged by some of the systems that we have in place, in terms of home ownership and access to high quality jobs, access to further education and training. But there is also a very major impact of those sorts of social and economic conditions on families, and I will continue to make the case that the family operates as a, kind of, a secure base, not just for a child, but also for an adolescent. So, when you have impacts on family functioning, by implication, you tend to get spill-on effects for children and adolescents.
In some of the research that we’ve done, we’ve really looked at that in close detail. This is a paper that you’ll see at the bottom of this slide around the use of social media by depressed adolescents. And that was a very interesting qualitative analysis of parents talking about their depressed adolescent. And, you know, you’d read that comment from participant, “The difference between what she,” her adolescent daughter, “would look at on the internet as a healthy and happy adolescent,” as compared to “a healthy and happy adolescent would look at is very different.” So, you know, this parent is then expressing huge concerns not only about her adolescent’s mental health, but also about what is she looking at on the internet and how are those two things interacting?
So, to think, then, about, you know, what some of the scientific literature tells us about associations with adolescent depression, or if you like, risk factors, as they’re often referred to. So this was a report done a little while ago now, but essentially, a very detailed review of the risk factors for adolescent depression. Now, this review identified 116 different risk factors. So, you could hardly say that there’s a dearth of research in this area. There’s obviously a great deal of research and the point is not to just accumulate risk factors. The point is to try to pull those risk factors together into some sort of meaningful themes and common elements.
And so, from that work on the various risk factors, this is a summary that I’ve produced of both risk and protective factors. And you can see that you can break it down into biological, psychosocial, comorbidities, such as sleep problems or other mental health issues. But the two that have been of particular interest to me and the interventions that I’ve tried to develop and trial, is – are these last two. There seems to be pretty consistent evidence that there’s a relationship between stress exposures and family social environment.
This was a study that we did on quite a large dataset to, sort of, tease out a particular aspect of that. You can have a read of that, the reference is down the bottom, there. But it shows that for all adolescents, there’s a relationship between the quality of parent-child relationships and their vulnerability to depression, but that’s exacerbated when they face stressful circumstances. And it’s particularly acute for females who are residing in families that are reporting low closeness. They have a much higher susceptibility to depressive symptoms. So, starting to move away from just that simple bivariate risk factor, into well, how do all of these variables work together to come up with a, sort of, model that might be a little bit more causal in trying to understand risk and vulnerability to depression?
We also need to consider the fact that it’s not simply just adolescence as the developmental stage that we should be thinking about, and particu – this is particularly pertinent to taking a prevention perspective. Prevention needs to intervene before someone starts to develop the disorder that’s trying to be prevented. And so, it’s important for us to consider, well, what are the earlier adversities in a child’s life that might make them vulnerable, such that when they enter into adolescence and perhaps experience some of those stresses that are part and parcel of adolescence, what makes some more vulnerable than others?
And this is a slightly, sort of, complicated slide, I apologise for that, but this is our attempt to think some of that through. So, some of these early vulnerabilities could entail genetic factors, could entail prenatal development or things experienced in very early infancy. And some of the vulnerability factors are very likely to be across these three domains. An affective disposition, you know, there’s clearly a lot of variance in young children in their ability to experience pleasure, or conversely, not experience it. There’s also different cognitive styles, which seem to set in fairly early. So this, sort of, negativity or negative bias in the experience that someone has, or their interpretation of their own experience, more to the point.
And then, there are clearly temperamental differences that have been researched for a long, long time, and we know that the young children that present with this reactive, or sometimes it’s called neuroticism, kind of temperament, have this degree of vulnerability. And so, for those individuals, moving into adolescence and going through the pubertal development, it’s likely that perhaps only a fairly low or negligible stressor might be the catalyst for the development of depressive symptoms. Those who don’t have that, sort of, earlier vulnerability and have a low vulnerability probably are also vulnerable to depression. But it would take a much higher stressor for that to occur and perhaps the depression might be of a more straightforward kind of a kind and more treatable in that particular way.
This is a more complicated model and draws on some work that a Researcher called Garber has come up with, called the “Stress Reciprocity Model.” Given that we know that vulnerability to stressful experiences is important, we have to distinguish between, on the one hand, stress exposure, and on the other, the person’s reading of a given situation as itself stressful, right? And so, that might draw on, say, personality or temperament factors, what one person finds stressful, another person may not, and it’s the interaction of how much stress you’re exposed to and then your interpretation of that stress, which is actually the subjective experience of the stressor. And you put those kind of factors against the backdrop of pubertal development and you have changes in endocrine systems that makes the stress response much more sensitised. And you also have sexual maturation, which in part, is a biological process, which culminates in, you know, much stronger motivations to have close relationships, intimate relationships and so on.
And so, you have a young person, sort of, seeking those kinds of close connections and interested in others in a way that perhaps they haven’t been before, but you also have them highly sensitised to the stressors that go with those kinds of interactions. And so, down the bottom here you have some of the vulnerabilities that go – that are inherent in the combination of those factors, such as, you know, personal and interpersonal challenges. Adolescents are doing things interpersonally that they’ve never done before. They’re also going through psychosocial transitions where they’re individuating from their parents and facing challenges that they had never – they’d never faced previously. And they have an increased vulnerability to interpersonal loss, disappointments, negative self-appraisal, and feelings of hopelessness and isolation.
So, you know, that gives you a rough idea of, kind of, a – some of the causal factors and type – the modelling and interaction of various components across development and then, as a young person moves into adolescence. You can see that there’s a strong emphasis, you know, perhaps the emphasis that I’ve given is really around the family environment as a potential, sort of, both risk factor and/or protective factor and also, exposure to stressors. So, that’s the kind of framework that I’ve used in some of my work on adolescent depression and its prevention.
So, let’s have a bit of a think, then, about, you know, what can we do? Very broadly speaking, you know, we have these two sources of research. On the one hand, we have longitudinal and population level studies, both those that are existing and also, the opportunity to develop new longitudinal studies, you know. And the kind of studies that I think will be very informative in this space would be those that begin in pregnancy and follow a cohort through into adolescence. And so, you can really get that developmental pathway really well mapped in these kinds of studies.
That needs to be combined, on the other hand, with studies that are intervention studies. So developing new interventions, trialling new interventions and then, conducting meta-analysis of existing trials to, sort of, see what seems to be working. And the combination of those two sources of information is really likely to drive the science forward in this area. Coming back to the interventions, so, well, how do we begin to think about what we might be able to do here? This is something that I’ve used a lot in my teaching, sort of, a spectrum of interventions, to think about the fact that, you know, we have options here to design interventions that are focused on either prevention or treatment, but we also should be considering interventions designed to promote mental health. Each of those kind – different sorts of interventions is going to be targeted in a different way, at different populations and so on. So, that’s another thing to think about in terms of designing prevention interventions, is to think about the optimal setting for the intervention.
Interventions can be designed to target a whole population. So they may be changes in policy or, you know, changes that are going to affect a whole state or a whole nation or a whole county, or what have you. Then you’ve got particular communities where, you know, working with the given community about what some of the particular risk factors that are going on in that particular community can develop a much more targeted kind of intervention to address what’s going on there in that particular location.
It’s quite a large literature and many attempts to develop prevention interventions in schools. This has had mixed findings. I think there have been some interventions that have successfully prevented mental health problems and depression in schools, but there have been many that haven’t. So, this is an area where, you know, we can learn a lot from as much the successes as the failures. As I mentioned earlier, the kind of work that I’ve done is focused more on the family, as working with individual families, or small groups of families where there are vulnerable adolescents. So, that’s more of a targeted intervention, where working with that family is likely to have a preventative, sort of, effect on the adolescent’s susceptibility to depression. And nowadays, there are quite a raft of different interventions that are focused on the internet and social media as a point of intervention, a lot of promise there. So, we also have to then think about the level of intensity of intervention and that tends to, sort of, intersect with these different settings. So, there can be low intensive interventions that are developed – delivered in a population or a community, but once you start, say, working with an individual family, obviously, that’s a much more intensive level of intervention.
Okay, so when we start to think about the level of the intervention and whether or not we’re – we should be targeting a population, a community or a school setting, for example, it’s really important to think about the fact that, you know, when we look at how depression develops over time, you know, this, kind of, slide here is presenting some data analysis that we did on a longitudinal dataset, and it’s using a technique called a ‘latent class analysis’. It’s able to divide up a large dataset into meaningful groups, and you could see that the symptomatology over on the Y axis, for a pretty large percentage of kids going through these age groups, from four and a half through to ten, is just simply very low and is flat. So, 80% of the children have no symptom and they have no – they’re not vulnerable to an increase over time. Whereas it’s really this blue line here, which is a group of around 8% of these children, who show this tendency to increasing symptoms over time.
So, you can see that, obviously, from a prevention point of view, that is the group that you would want to target. And it’s very important to note that from a population point of view, so going into a school, not all of the young people are going to be vulnerable. And so, it’s very important when designing these kind of interventions, that for the people who are not vulnerable, we’re not doing any harm to them. We’re not, sort of, stirring things up, or we’re not alerting them to symptoms that they don’t actually have, and they don’t have any vulnerability to having them, right? So, this is the tricky part, I guess, of designing interventions, is that if they’re at a population level or a school level, they have to be of some benefit to everyone, whether or not they carry a vulnerability or not.
Now, I also mentioned that a way of working in this area is to conduct reviews and meta-analyses of existing studies and fortunately, we have some great Researchers who have already done that, kind of, very intensive work and then, this publication here of a Cochrane review by Sally Merry and her team, has been really setting the standard of rigour around the review of existing prevention and interventions. The team that I work with have done some more fine-grained analysis of the interventions that were used in the – this Cochrane review.
And you can see that the interventions, which have generally been successful in preventing depression, have certain characteristics about them and these characteristics are that they make efforts to include families, that they have professional facilitators. So that’s distinct from, say, going into a school and asking the Teachers to do the intervention, or asking community members to do an intervention. The interventions that have been – were found to be successful, generally have been run by professional facilitators. The age at which the interventions have targeted has been pre-adolescence, this is prevention, of course, so the eight to 12 year range is really the optimal range. And the final characteristic of the most successful interventions that have been reviewed in this Cochrane review are that they have an interpersonal focus. So, they teach children and young people skills about how to have effective relationships with their peers, with their parents and that sort of thing. So, they have an interpersonal focus.
Alright, so, in this final section four, and I want to move onto some of the specific work that I’ve done around prevention, working with families. You know, I’ve been fortunate to work with a number of colleagues in developing and designing an intervention called “Behavioural Exchange and Systems Therapy.” And we’ve done a number of clinical trials of this intervention and written up descriptions of the programme logic and the underlying theory and the particular techniques that are used in this approach. So, this is a family group intervention. You might work with about four or five families who come along and have an eight-week programme, usually two hours per week, so that’s 16 hours of therapy in total. And there’s a focus on working with both the parents and the young person, and the young person’s siblings, so it eventually becomes a full family intervention model.
It draws on, obviously, family systems theory, it draws on some aspects of attachment theory, and it, over time, has developed a number of, sort of, specific techniques. There is a training, it’s – so, it’s a two-day training for people who wish to undertake and use that model. And I’ll just go through, kind of, quickly, some of the techniques that we do use in that approach and speak to parents about the fact that, you know, parenting an adolescent requires a, sort of, shift in their developmental stage themselves. So, parenting is conceptualised as, itself, a developmental process.
We know that young people, from infancy to childhood, to adolescence, they themselves, are going through a developmental process, but parents, equally, need to change their parenting a lot – across those different stages of development. And so, on some occasions, we find that parents are cha – struggling with their parenting role of an adolescent because they haven’t, sort of, adjusted their parenting style to some of the things that adolescents are wanting to do, and that may be parenting their young person more in a more childlike kind of a way. So, we have a exercise where we present the developmental lifecycle of families and seek some discussion around that.
Another part of the intervention, which draws on what I was talking about earlier around modulating stress reactivity, is – are a number of interventions that are designed to help parents to learn self-care techniques and to modulate their own stress reaction, and to take positive action for themselves to deal with their own stresses in their lives. Which has a modelling effect for their young person to see that the parent is able to regulate their own emotional states. And so we sometimes use the metaphor of the ‘oxygen mask’, that you’re all probably familiar with from flying around in planes, that the host and the hostess will tell you to put on your own oxygen mask before seeking to help the young person. And so, that’s a very, very important metaphor for a lot of parents, who find themselves feeling quite helpless and hopeless in the context of their adolescent’s mental health issues.
We have an emphasis drawing on more of the, sort of, systems theory ideas of getting parents to try and do things differently and to interact with their young person to change communication patterns. And we call this the ‘red buttons’ task, which is, sort of, designed to get parents to speak with their young person about some of the red buttons, or the trigger points, that occur in the family’s communications and how they can, kind of, unpack those and rethink how they actually want to communicate and get along as a family. So, that’s just, very, very briefly, a bit of a taster of some of the techniques that are used in that family-focused intervention that we’ve trialled, and there are a number of papers there that you could look up if you want further information.
So, I’ll just say, by way of conclusion, then, that I think you’ve had a bit of a taster of the fact that depression in adolescents is complex and that there are multiple contributions and causes that we could think about in terms of why depression occurs and why adolescence is a particularly vulnerable time for it. Fortunately, there is evidence from pretty robust reviews and meta-analyses, that prevention efforts to intervene for adolescent depression can be effective, and that is very important to know that. It’s also important to go through those studies and work out, you know, what are the key ingredients, what are the elements that have proven to be effective in those interventions?
Interventions need to be very carefully designed, thinking carefully about who the target of the intervention is and what the level of intensity of the intervention is going to be. And you can see that I’ve presented the fact that there are interventions that go from the whole population, a community or a family-based that – so, it’s important to think through what’s required in given circumstances. Finally, prevention is a really critical part, I think, of the health system and a part of the mental health system which has been relatively neglected, given the urgent needs of direct clinical care. And that’s understandable, but it’s – now that the evidence is accumulating, I think there’s a more robust case to focus on prevention. And the evidence supports that quite strongly, suggesting that prevention can be effective and it can also be a very efficient use of resources.
Okay, so that’s really it from me. Thank you very much for your attention.