It's celebration time for the researchers and staff of the YOUth cohort study, who have just welcomed their 1000th participant. Eventually 6,000 children will be contributing to this large-scale, long-term cohort study on child development. So who are all these young participants, and what does YOUth want to find out about them? Cohort manager Charlotte Onland-Moret determines the composition of the group and monitors the quality of the research. ‘Anyone who joins YOUth, is helping scientists and the children of the future in a big way.’
Charlotte Onland-Moret sees 6,000 children grow up as part of the YOUth Cohort Study
‘Joining YOUth means helping the children of the future’
YOUth charts how children grow up and how young brains develop. How do the aspects involved in that process influence a child's behaviour? In order to answer this question, you can't ‘just’ study a random group of children. You first need to consider what the group should look like. Charlotte: ‘Who do we want to shed light on when the study comes to an end? Do the children who will ultimately take part accurately reflect the people I want to be talking about?’ When you know the target group for your research, then you can start thinking about the best approach: ‘When do you want to see them, and how often? There are lots of choices which need to be made. What should we do with (step) brothers and sisters, and what about adopted children? These are the kinds of thing you need to think about.’
Who, what, where and why
The research team determined two occasions at which people can join the study. Charlotte: ‘First of all, we have pregnant women with their babies, who we follow until they are around seven years old. This part of the study is called YOUth Baby & Child. Then we also monitor children from the ages of 8, 9 or 10 until they are young adults. This is known as YOUth Child & Teenager. Following both groups gives us a complete picture of how a child develops, from the womb to young adulthood.’
Pregnancy and (pre)puberty are crucial moments in a young life: ‘If you want to talk about the origins of behaviour, you need to start with conception’, says Charlotte. ‘Even in the womb, children are exposed to all kinds of external influences which affect their behaviour later in life. Children who are entering puberty are also a very important group. At that time in your life, you are going through some very significant developments.’
YOUth involves children from all layers of the Dutch population: ‘In practice this is actually quite difficult to achieve, as it is hard to reach some people. Not everybody speaks or understands Dutch well enough, for example, although this is necessary if you are taking part in the study. We recruit our participants from the province of Utrecht. This keeps the travel time manageable for the participants. According to Statistics Netherlands (CBS), the Utrecht population forms a good reflection of the Netherlands as a whole.’
YOUth only studies one child in each family: ‘People often wonder why both of their children can't participate. Children in the same family grow up in the same environment and share genetic material. As a result, measurements among brothers and sisters tend to be very similar. You would therefore need far more than 6,000 children to draw conclusions which apply to all children. For this reason, we decided to only include one child per family.’
Big and small brains
Charlotte: ‘Our main question is deliberately very broad, as we wish to collect as much high-quality data as possible. This will allow us to create an infrastructure in which we can carry out high-quality scientific research in the long term. Other researchers will then be able to use our data to answer all kinds of scientific questions about children and their development. This is also what makes it challenging: we need to set up our research in such a way that we can seek answers to questions in the future that we haven't even thought about yet.’
YOUth has a clear focus: brain development and behaviour. The researchers are collecting a treasure trove of information for all the participants in these areas. They measure and weigh, ask questions and observe how children (together with their parents) talk, watch and play. Of course they also study the brain in great detail. Charlotte: ‘We measure how the brain grows and develops from pregnancy to around 18 years of age. We start out with 3D ultrasounds when they're in the womb, use EEGs for babies and MRI scans for older children. We are the only long-term study which does not just examine the shape and size of the brain, but also the brain functions: what happens in your brain when you are performing a particular task?’
The participants in YOUth Child & Teenager only attend one research day every three years. All the same, the researchers can carry out brain scans at all ages from 8 upwards: ‘Children come to us when they are 8, 9 or 10 years old, then they come once every three years. As a result, the age at which children start the research and when they return is always different. If you just measure all the children when they are 9 and then all when they are 13, you won't be able to say anything about the interim period even though these are crucial years: developments come thick and fast during puberty. It's a better idea to measure children of all ages, even though it is more of a challenge from a logistical point of view!’
What is normal anyway?
As well as being a scientist, Charlotte is the mother of three children. ‘My oldest daughter has just reached puberty. Thankfully, everything has gone smoothly with her so far. I've noticed that other people around me are having much more trouble with their children. Then I think to myself, why is that? Why does my own child sail through secondary school, while other children don't? In my environment, I have noticed that people are in need of guidance: how can I influence this myself?’
Learning to understand why one child grows up with no issues and others don't can make it easier to find solutions and to improve care and education, for example. ‘If you know how something works, you also know how to intervene.’ Numerous factors determine how a child develops and the differences between people often lie in the little things. This is why it is crucial to study as many children as possible.
‘We need a lot of data to establish what influences children's behaviour’, explains Charlotte. ‘It's not just about how your brain is growing, but also: how are things going at school, what do you eat at home, what about friends, TV, social media etc.? People will be helping us and the children of the future enormously by taking part. And of course all the data relating to our participants is completely confidential.’
Although residents of the province of Utrecht can apply for the study themselves, in order to reach more people YOUth works with local schools and midwives. ‘Many of them support YOUth and we are working with them to tell parents and children about the study. It's going really well.’ Many of the children enjoy taking part, says Charlotte. ‘I really love their enthusiasm. The MRI scan is particularly popular. And most children don't have a problem with giving blood, they're really brave. It's great for the study, as we can tell a lot from the blood.’
In fact, you can measure pretty much anything in blood. ‘For example, blood has the best quality DNA, the genetic material which you inherit from your parents. And we can also measure everything which is produced by your own body or which ends up in your body through ingestion: anything from hormones to what you have eaten. From the blood, we can also obtain information about other things such as your immune system.’
Patience is a virtue
As well as blood, YOUth also collects hair, performs buccal swabs and collects saliva from the older children. The researchers can learn a great deal from these substances: ‘For example, we can see stress hormones as well as exposure to tobacco, drugs and other chemicals in your hair. In saliva, we mainly measure sex hormones. Buccal smears are also very interesting to us, as buccal cells come from the same stem cells which make up your brain.’
It will take some time before we can expect the initial results of YOUth: ‘We want to establish what determines how a child develops as the years go by. How does what is happening now affect the child in later life? In order to do this, the children need to have visited our research centre at least twice, spanning a period of at least six years.’
The project is very exciting for the researchers themselves, as well: ‘We will collect all the data first and only analyse it afterwards. If you draw conclusions in the meantime, this influences the subsequent research. This must be avoided; we carry out thorough research which generates high-quality results. But I would rather take a look every day; like all researchers, I am extremely curious!'