In this podcast, we are joined by social epidemiologist Dr. Becca Lacey of the Research Department of Epidemiology and Public Health, University College London.
Becca is the first author of the JCPP paper “Testing lifecourse theories characterising associations between maternal depression and offspring depression in emerging adulthood: the Avon Longitudinal Study of Parents and Children” (doi.org/10.1111/jcpp.13699). This paper will be the focus of today’s conversation.
To set the scene, Becca provides an overview of the paper and tells us a little about the methodology used, before turning to some of the main findings.
With a sensitive period being defined as a point in time when maternal depression might have more of an impact on the child’s mental health, Becca elaborates on the importance of her paper’s assertion that the sensitive period continues through to adolescence.
Becca’s study also found that emerging adulthood depressive symptoms were best explained by the accumulation of exposure to maternal depression, and not the infancy-sensitive period model. Becca explores what the implications are of this finding for CAMH professionals and other health professionals.
Furthermore, Becca comments on some follow-up research that is in the pipeline and shares her take-home message for our listeners.
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I am a social epidemiologist who applies a life course approach to understanding the importance of the early family social environment for health across the life course. I currently lead the quantitative side of an NIHR funded project with the Children and Families Policy Research Unit on interparental violence, parental substance misuse, parental mental health and effects on children’s mental health. In addition to this, I am interested in how informal caring affects health and am a Co-I on a large, European Consortium (EUROCARE) investigating inequalities in informal caring on health and social participation.
Before these projects I led an ESRC grant on early life adversities and mental health over the life course using large population cohorts (Millennium Cohort Study, 1958 British birth cohort and the Avon Longitudinal Study of Parents and Children). I was also previously a Co-Investigator on a Nuffield Foundation funded project looking at long-term outcomes of looked after children in the ONS Longitudinal Study and PI on a follow-up project looking at the living arrangements of children in the Northern Ireland and Scottish Longitudinal Studies. In previous roles I have worked on work-family life courses and how they affect health in the British birth cohorts. (Image and bio from UCL Institute of Mental Health)
[00:00:32.050] Jo Carlowe: Hello. Welcome to the In Conversation podcast series for the Association for Child and Adolescent Mental Health, or ACAMH for short. I’m Jo Carlowe, a freelance journalist with a specialism in psychology. Today I’m interviewing social epidemiologist Dr. Becca Lacey of the Research Department of Epidemiology and Public Health, University College London. Becca is the first author of the paper “Testing lifecourse theories characterising associations between maternal depression and offspring depression in emerging adulthood: the Avon Longitudinal Study of Parents and Children” recently published in the Journal of Child Psychology and Psychiatry. This paper will be the focus of today’s conversation.
The JCPP is one of the three journals produced by the Association for Child and Adolescent Mental Health. ACAMH also produces JCPP Advances and the CAMH. If you’re a fan of our In Conversation series, please subscribe on your preferred streaming platform. Let us know how we did with a rating or review and do share with friends and colleagues. Becca, welcome. Thank you for joining me. Can you start with a brief introduction about who you are and what you do?
[00:01:36.450] Dr. Becca Lacey: Yeah, sure. So, I’m Becca Lacey. I work in the International Centre for Lifecourse Studies in Society and Health at UCL. I’m a social epidemiologist who conducts life-course research. And more specifically, my research interests are in how the early-life social environment affects health, and that’s both physical and particularly mental health, across a life course. In the last few years, I’ve done quite a bit of research on adverse childhood experiences, or ACEs, in particular, and maternal depression is potentially one of those experiences.
And all of my research uses large, longitudinal data sets. And so, these include data sets like the Millennium Cohort Study; the Avon Longitudinal Study of Parents and Children, which is what we’re going to be talking about today; and also, the British Birth Cohorts as well.
[00:02:15.980] Jo Carlowe: Great. Thank you. Let’s turn to the paper then. So, this is “Testing lifecourse theories characterising associations between maternal depression and offspring depression in emerging adulthood: the Avon Longitudinal Study of Parents and Children” recently published in the JCPP. Becca, can you start with an overview of the paper to help set the scene?
[00:02:37.900] Dr. Becca Lacey: The title’s a little bit of a mouthful, so apologies for that. But we know from quite a few previous studies that the mental health of mothers is really important for the development of mental health problems in children. And before this study, we didn’t really know a huge amount about how the timing or the duration of maternal depression affected children. And certainly not taking such a long-term view, looking right across early life, looking well beyond the antenatal period in particular. So that’s something that we wanted to do here. We wanted to look at how the timing and duration of maternal depression affected depression in children right through to late adolescence, or, as we term it in the paper, emerging adulthood. So, looking as far as young people’s early 20s.
[00:03:16.810] Jo Carlowe: Before we look at the findings, can you tell us a little about the methodology that you used?
[00:03:22.180] Dr. Becca Lacey: To answer our research questions, we needed a data set which had repeated measures of maternal depression through the child’s early life, plus also had information on the mental health of the child themselves. This is actually quite difficult to find and we’re really lucky in the UK that we have a series of very rich longitudinal data sets. So here we’ve used the Avon Longitudinal Study of Parents and Children, which is also known as ALSPAC or the Children of the ’90s cohort.
So, the ALSPAC study is based in the Avon region in the southwest of England. It includes around 15,000 children who were born in the early ’90s, so they’re now in their 30s. We have information on the child and their development right from pregnancy through to the present day, and we also have very rich information on their parents as well, which makes it a really good data source for our type of research questions.
We’ve used information on maternal depression from pregnancy with the cohort child right through to when that cohort child was age 19. So, this includes information on depression diagnoses, or having a high score on the Edinburgh Postnatal Depression Scale, which includes information on a wide range of depressive symptoms. We have this information across 13 time points from pregnancy right through to age 19. So it’s a really fantastic data resource that we’ve got available to us.
In terms of the young person’s mental health, we’ve used a measure of depressive symptoms at age 21. This is the short moods and feelings questionnaire that’s used on various different data sets. And then in terms of the more specific statistical methods, we’ve used this thing called the structured life-course modelling approach. It’s also known as SLCMA, which is its acronym. So, this is a fairly recently developed method which allows us to test a series of different life-course hypotheses. So, these different life-course hypotheses capture different aspects of timing and duration of maternal depression.
So, the three hypotheses that we were particularly interested in here, so the first one was looking at sensitive periods. So, a sensitive period is a defined point in time when maternal depression might have more of an impact on the child’s mental health. For lots of early-life experiences, infancy is thought– Infancy and early childhood are thought to be the most sensitive periods. In this study, we were able to actually look at six different sensitive periods. So, this included pregnancy, infancy, and then early, mid, and late childhood as well as adolescence. So, we’re really able to look far longer than most previous studies had been able to do so.
We also looked at accumulation. So this is the idea that the more time periods that the mother is depressed, the greater the effect that this will have on the child’s own mental health. So really it’s capturing that kind of chronic experience of maternal depression.
And then finally, we’ve looked at instability. So the instability hypothesis is that it’s the frequent changes in maternal depression status that’s really important for adolescent mental health. And so this SLCMA methodology allows us to formally test which of these different life-course hypotheses, or even a combination of these hypotheses, best fit the data that we have available to us.
[00:06:06.575] Jo Carlowe: OK. Fantastic. It’s really comprehensive. Can you tell us some of the main findings?
[00:06:12.195] Dr. Becca Lacey: It was a bit surprising, really. We went into this piece of work thinking that a sensitive period in infancy or early childhood would be the most important thing. So, this is the period when the child is most dependent on the mother and when things like attachment are really important and being developed. However, we found something quite different to what we expected. So we found that for boys, it was this accumulation model that was most important.
So, the more time period or the longer that the mother was depressed, the more depressive symptoms the young person reported when they were age 21. For girls, it was a bit more complicated. So, we found that the accumulation model was important, but it was in combination with a sensitive period in mid-childhood, so between ages of about six to eight years. So, the longer that the mother is depressed, the higher the depressive symptoms in young women, but especially when the mother was depressed when the daughter was aged six to eight years. It was those two things working in combination.
We were quite surprised by this finding of the importance of mid-childhood for girls, given that there have been so many studies that highlighted the importance of infancy and early childhood. But there have been very few longitudinal studies which have been able to take such a long-term view as we have been able to do. So many studies just focus on maternal depression around that antenatal-period, and we were able to go so much longer and compare those different age groups to the antenatal period, which was quite good. So, what might be going on, I guess, [INAUDIBLE]
[00:07:29.040] Jo Carlowe: Yeah, absolutely.
[00:07:29.490] Dr. Becca Lacey: –for age six, the big question, right? So this was a bit tricky to answer in the paper, if I’m totally honest. So I mean, some researchers have found that girls potentially provide more emotional support to mothers than boys perhaps do. It might be that girls seek support differently from their peers or from other adults. These are all things that really need unpicking, I think, a bit more, and which we don’t always have great data on in the longitudinal studies that we use.
There was another study, which also used the same statistical method and also used the same data set, so ALSPAC, looking at a range of different early life adversities and how the timing of those adversities affected epigenetic aging. And those authors actually also found in this data set for girls that maternal mental health problems experienced around age six were particularly strongly associated with epigenetic aging. So there’s something certainly going on in this cohort around that kind of age, because we found it to do with depressive symptoms, but there’s also another paper that’s found something similar. But I think, again, also this finding probably does need to be replicated and explored in other studies as well and other data sets to see whether it holds across studies. That would be really important to have a look at.
[00:08:34.710] Jo Carlowe: You’ve already touched on this, but you talked about sensitive periods, and yet, in your paper, you suggest that the sensitive period continues through to adolescence. Can you elaborate on the importance of that assertion?
[00:08:48.833] Dr. Becca Lacey: So, I think it depends on what experiences we’re looking at, because they might have different sensitive periods. So that’s something important to think about. Here, we had really good longitudinal data for a really long time period. So right from pregnancy, through to early adulthood. So, we were able to take a much longer term view, well beyond that antenatal period, that many other studies have focused on.
I think there have been so many studies that have looked at the sensitive period in infancy and around that kind of period at the time. We were actually able to look far longer than that and I think that’s quite unique. We’re really lucky with the ALSPAC data set. I mean, as I mentioned, we did expect to see that infancy or early childhood was most important, and that’s mainly because there is so much evidence, [INAUDIBLE] the importance of experiences in very early life.
But there have been so few studies that have been able to go beyond that. Yeah. So we were able here to pit this idea against sensitive periods basically later on in childhood and adolescence, so we did find this finding with girls aged six to eight. But there doesn’t seem to be really any sensitive periods going on for boys. It was all about accumulation, or that chronicity, in maternal depression.
[00:09:50.970] Jo Carlowe: Your study finds emerging adulthood depressive symptoms were best explained by the accumulation of exposure to maternal depression, and, as you said, not the infancy-sensitive period model. What are the implications of this for CAMH professionals and other health professionals?
[00:10:07.890] Dr. Becca Lacey: So, I think the implications of this study are really important. In many countries, including the UK, there’s a really substantial focus on supporting maternal mental health during pregnancy and also during the perinatal period. So mental health is regularly monitored by midwives, by GPs, health visitors during this period. However, our findings suggest that, actually, maternal mental health continues to be important far beyond this period, and therefore one thing that we suggested was that these regular conversations and check ins about maternal mental health continue into childhood.
Obviously, this all comes down to resources, but the opportunities for these conversations already exist. So for example, things like a routine child health appointment. So, weigh ins, child development checks, vaccinations. There are those regular check ins with children. Potentially, mothers are also present, they could be part of the conversation. And also, given that we found that accumulation was important, so the chronicity of, or chronic nature of, maternal depression, there’s a real– I think an impetus to try and tackle depression early on and to prevent it becoming a longer-term problem for the mother, but also for other members in the family as well. Because here we’ve shown that it does seem to have an effect on children as well.
[00:11:15.450] Jo Carlowe: And Becca, is there anything else in the paper that you’d like to highlight?
[00:11:19.000] Dr. Becca Lacey: Not really in the paper itself, but just to say that we’ve only looked at the mental health of mothers here. We’ve not also looked at the mental health of the mother’s partner. And that’s a study that we’d really like to do, but it’s quite a bit trickier, because we have less information on the mother’s partner in the ALSPAC data set and there can be changes in who that person is over time. So, I’d like to really point out the mental health of dads and partners is also likely to be important. It’s not all about mothers. But it’s just really– it’s far harder for us to research that certainly using this data set we’ve got.
[00:11:47.770] Jo Carlowe: Are you planning some follow-up research that you can tell us about? Or is there anything else in the pipeline that you would like to share with us?
[00:11:55.203] Dr. Becca Lacey: So, this piece of work came out of an ESRC new investigator grant that I held. So, it’s now finished actually, this was the last piece of work from that. So, there’s nothing directly following on from it. The focus of that grant was on how earlier life adversities cluster and what that meant for mental health and stress biomarkers over the life course. And we’ve published quite a few papers from that grant now, including a JCPP practitioner review on the strengths and limitations of ACE scores.
I’m now working on a NIHR Children and Families Policy Research Unit project, looking at how maternal and paternal depression relates to interparental violence and what that means for the mental health of children and adolescents. And that project is also using the ALSPAC cohort. It’s a really good data set for these types of questions. And so, it’s a related piece of work, basically, that I’m continuing to work in this area.
[00:12:45.130] Jo Carlowe: When might that come to fruition?
[00:12:47.350] Dr. Becca Lacey: That’s a good question, isn’t it? The paper’s sitting with journals at the moment. We’re still waiting to hear. Hopefully, soon.
[00:12:55.760] Jo Carlowe: Finally, Becca, what is your take-home message for our listeners?
[00:13:00.582] Dr. Becca Lacey: I think, basically, the mother’s mental health is important. It’s not just important for mothers, but also for children, and that it continues to be important beyond the antenatal period. And as a life-course researcher, I’m obviously going to say that timing and duration of maternal mental health is important as well. So, we need to be looking at preventing long-term maternal depression, understanding what might work, where are the opportunities to intervene and how can we better support mothers with depression over the longer term, really.
[00:13:27.250] Jo Carlowe: Thank you ever so much. For more details on Dr. Becca Lacey, please visit the ACAMH website, www.acamh.org, and Twitter @acamh. ACAMH is spelled A-C-A-M-H. And don’t forget to follow us on your preferred streaming platform. Let us know if you enjoyed the podcast with a rating or review, and do share with friends and colleagues.