Irene Pappa studied biology and medicine in Greece and chose to specialise in psychiatry. She likes the range of patients in psychiatry, she says: "From one session to the other, you can really see the impact of your work on their lives, the difference you’re making. And you don’t need any sophisticated tools: it's just you, your knowledge and the other person."

Biological psychiatry
Until now, there has been a lot of prejudice against biology in psychiatry, Irene explains. "It’s considered a more theoretical science and very often it’s seen differently from other sciences in the field. But with biological psychiatry, you can really see that psychiatric diseases are in fact biological diseases that can be treated, and the causes of which can be resolved."

Behavioural problems in children
In 2012, Irene moved to the Netherlands to begin her PhD research into the genetic and epigenetic (cellular and physiological trait variations not caused by changes in the DNA sequence) determinants of children's behavioural problems at the Erasmus Department of Pedagogical and Educational Science.

Irene: "I wanted to combine biology and psychiatry, and this project was an exact combination of the two. My focus within the research is on behavioural problems in children, such as ADHD, sleep problems and aggression. We’re using genetic tools to see if there’s a link between specific genes and these traits."

"The best thing was that my professors gave me the time to discover and learn all the things I needed to know, such as different statistical methods I didn’t know before. That first year, I took different courses, attended meetings and conferences and discussed the topic with lots of different people, which was really helpful."

Generation R
Her PhD project is a result of the collaboration between the Erasmus University Rotterdam, the Generation R study and Leiden University (Centre for Child and Family Studies). The Generation R study started in 2002 and is examining the growth, development and health of 10.000 children growing up in Rotterdam. The children are followed from early pregnancy to young adulthood. The central question is why one child develops well while another child does not, or less well.

Erasmus Medical Centre has an enormous dataset with the whole spectrum of genes for every child within the Generation R study. Irene and her team have measured different phenotypes and different problems in children. Irene: "I try to see if the kids that are more aggressive, for example, share more common genes than other kids. This statistical analysis shows that this is indeed the case for a few kids with highly problematic behaviour. Understanding the genetic underpinnings of behaviour, it becomes easier also to understand the psychopathology and how it developed."

Heritability
A topic she's currently working concerns estimating heritability. Irene: "We always have the impression that certain traits in children are heritable, but we have never really measured the extent to which this is true. In this analysis, we make estimates and see that, as we suspected, ADHD for example is to a great extent heritable – depression, on the other hand, not so much."

"In our research we have discovered things previous researchers were unable to identify. If we can use this information to identify a group of kids at high risk, we can intervene at an earlier stage or give them different treatment. Our research could potentially add to the understanding of the severity of each individual case."

Promotion nearing
With her promotion date in sight (20 November, 2015), Irene spent the last couple of months mostly behind the computer, statistically analysing the data she generated in the lab, and writing her thesis. It might sound boring to other people, but it's definitely not to Irene.

"I just have a great interest in this topic and I want to see whether the hypotheses I had when I started are true. We generally have some ideas: for example, that aggression or depression runs in certain families, and now I can actually see whether this is true or not."

Step by step
People don't always understand her excitement when she discovered, for example, that a certain genetic variation is associated with problem behaviour in children, Irene says. "You’re happy because you found this tiny, little thing?", they ask. But to me it's special. The findings I have might be small advances, but together with all other small steps they can in the end give us the big picture."

Solving the mystery
"It motivates me that eventually I may find something that can explain even a very small part of the variance we see. That I can explain why one person responds well to therapy and another person doesn't. It’s like solving a little bit of the mystery. Sometimes we say that it’s a matter of chance why a child has certain behavioural problems, but then I can explain that it’s not chance, it’s biology."