The Human Mind and Migration program highlights the research that expands and reveals the impact that migration has on various communities. The neurobiological effects from reshaping of a social environment will be explored throughout the study. We interviewed Hannah Jongsma, a postdoctoral fellow at UCL’s Division of Psychiatry.

Hannah Jongsma studies the relationship of ethnic communities and their mental health and illness in new environments. We asked her to share some of the findings of the extensive European Gene-Environment Interactions (EU-GEI study). 

The Gene-Environment Interactions Study is looking at psychotic disorders such as schizophrenia, but also bipolar disorder, and depression with psychotic symptoms in minority communities in France, England, Italy, The Netherlands, Spain, and Brazil.


Hannah, the European Gene-Environment Interactions Study is extensive, both in terms of duration and geographic coverage. What are you looking to uncover?

The European Gene-Environment Interaction Study covers five European countries and Brazil. We had 17 participating sites across the six countries. The research looks at variations and incidence between ethnic groups in those countries.

We established the number of new cases per head of the population. I am looking at the case control data—the people with the first episode of psychosis at mental health services. About half of all new cases agreed to take part in the full study, and underwent about six hours worth of assessments.

How many people are participating in the study?

We have about 1,200 cases and about 1,500 general population controls recruited by general practitioners (GP). The control group in the study is still not an entirely representative population, because that’s really difficult to get. But it’s much better than asking psychology undergraduate students.

What are some of the findings?

We’ve known for quite a long time that psychotic disorders are much more prevalent in ethnic minorities. They’ve a much higher rate of disorder.

It seems to be quite specific to being an ethnic minority, not to a particular ethnicity. If you, for instance, look in the UK, the Black Caribbean group is at the highest risk. But if you look in Caribbean countries like Jamaica and Trinidad and Tobago, the risk is quite similar to the white British population. There’s a discrepancy. There’s something to being Caribbean in the UK, not being Caribbean as such.

Do you then find similar outcomes for the same minority group in different countries?

No, that’s another thing. In the Netherlands, the Moroccan people have the highest risk of psychosis. People from the Dutch Caribbean or Suriname have a slightly increased risk, but not nearly as much as Moroccans. If you look in France, there is quite a large North African population, but largely from Algeria and Tunisia. They don’t have so much of an increased risk. In France, the people from sub-Saharan Africa have a much-increased risk. It seems to be very context-dependent.

The risk of psychosis is not only increased in first-generation migrants, but also in their children—second-generation migrants. Refugee status might have to do with a traumatic migration experience and increased risk. However, that doesn’t explain everything. There are a vast number of people who are born into an ethnic minority in a certain country who never migrated. So migration itself is not a full explanation for that increased risk. There’s something about that social context.

Social context, you mean the environment migrant families live in, the connections they have with others in the community?

There are many neighborhood level influences on psychotic disorders. One of them is the ethnic density effect, which means that when people from minority backgrounds live with others from that same minority background, their risk of psychosis goes down. Or as if they live with fewer people of the same background, it goes up.

It is not a full explanation. This holds for some, but not for others, or for some in the second generation, and some for this first generation. One of the things we looked at is social disadvantage such as people’s paternal socioeconomic status. There’s no reason to suggest that a person’s illness has an influence on their parent’s socioeconomic status.

When you look at people’s own socioeconomic status, you run into reverse causality quite quickly. One of the things that happens before people develop a first episode of psychosis, they will often become quite withdrawn. People can quite easily lose their jobs or drop out of school.

What are some of the challenges when you are working with such a large data set across these many countries?

This was such a large international study. We had to look at quite broad groups, which is a bit of a disadvantage. One of our groups was black and the other group was Asian. Those are quite heterogeneous groups.

Particularly, the Asian group in Britain usually means people from the Indian sub-continent. Whereas in the rest of Europe, the group consist of mainly people from Far Asia such as China. We found that, by and large, the Asian group doesn’t tend to have so much social disadvantage. They had quite good levels of education and quite good paternal socioeconomic status.

Whereas we found that for instance the black group and the North African group faced a much higher social disadvantage.

What are the factors you examined that have not been considered before?

The other factor is this idea of how different you are to the majority population. That’s really quite tricky to capture. We go on to the idea of cultural distance, and that seems like a very vague concept.

There’s quite a large business literature, which is based on this idea of differences in managerial values. They say that linguistic distance is quite a close association. We had data on people’s first language and on people’s fluency in the majority language. We found that it seemed to play quite a large role, particularly for first generation migrants. If you’re thinking of public health interventions, language classes do seem to be quite an obvious candidate.

With the research you have seen, what would be the top two-three policy advice regarding mental health and migration.

The research ties into a lot of the literature about the social determinants in health. It seems to be that poverty alleviation: food and security, education opportunities, job opportunities play a really important role in people’s mental health, and also people’s physical health.

That’s really where we should start. The world seems to be slightly going in the opposite direction with more inequality.

The Director of Centre for Research on Migration and Mobility in Hong Kong has also seen mental health issues being more prevalent among the foreign domestic migrants. We also spoke about race and ethnicity. People from Mainland China who are migrants into Hong Kong are of the same race as Hong Kong Chinese people. And yet, they face integration issues. Have you come across this issue about race and ethnicity?

Yes, for my PhD, I had to write a statement about why we look at ethnicity and why we don’t look at race anymore.

There’s a whole radicalized history behind looking at race, with phrenology: measuring people’s skull size [and predicting personality traits]. It’s all meant to show that white people are superior somehow. Race is based on the idea that there are biological subspecies of humans.

Humans are one species and there are different ethnic groups within that. The way ethnicity is ascribed is also quite different in every country. In the UK, for instance, it’s very much self-described as what you fill in on the census.

I think that quite accurately reflects the kind of social identity of ethnicity. Because you’re only one ethnic group compared to what’s around you. In the UK, I’m classed as White Other, whereas back in the Netherlands, I would just be [White] Dutch. Your ethnic identity is very much dependent on your context.

What have you experienced as a migrant?

I sound English and I could as well be English. We also tried to look at people who were of White ethnicity, but didn’t live in a country they were born in—economic migrants like myself. It takes quite something to move countries. Generally, people who voluntarily move countries tend to have quite good physical and mental health.

To me, the study is pretty alarming—a lot of people dealing with mental health issues go untreated, right?

Yes, people can’t hold on their job, people go on support. Even people who do receive early intervention services, they’re often limited to three years of service. Then people are discharged to carry on as normal. We would never do that with someone who’s got cancer.

We wouldn’t say after three years, well, there you go. Go back to your GP [general practitioner] and come back once every year to review your medication. The way we treat people with mental illness is not okay. It doesn’t carry the same importance as other illnesses.

I was wondering if you could talk about some of the confounding variables in your research.

With respect to confounding variables, we know that psychosis peaks, particularly in men, before the age of 35. In women, it peaks in the 18 – 24 age group. There’s always this idea that men have a higher risk of psychosis than women. That’s true overall, but it’s only true in earlier age groups. After age 50, we find it is about the same. Women were at a slightly higher risk. Sex is quite a confounding factor and also childhood trauma.

Childhood trauma, and particularly things that are carried out with an intention to harm, so abuse. Your parent dying when you’re five is childhood trauma, but there’s a lot less malicious intent. [Developmental psychopathologist] Helen Fisher discovered that child abuse may be one of the causes of psychosis.

I noticed that the numbers in Brazil were really high in comparison to other areas that you looked at. Did you have a larger group in Brazil?

Yes, we had a really large sample from Brazil. We had 17 settings where we recruited people [to participate in the study]. In total we found about 2,400 people with their first episode of psychosis. Brazil contributed quite a lot in proportion: some 600 cases.

Brazil is very different [compared to the European countries in the data set]: it’s the only lower-middle income country. It’s also the only country [in the study] that has been colonized.

There have been a lot of ethnic minorities for quite a long time in Brazil. There was no one in our Brazilian sample that didn’t have Portuguese as their first language. We can’t quite apply certain things to Brazil, but some of the problems still seem to play it out.

In general, the countries that we have in our sample have very different migration histories. In Italy and Spain, migration’s really quite a recent phenomenon. There’s always a lag time between when people arrive and when they tend to develop psychosis. Whereas in France, the Netherlands, and the UK, mass migration started much earlier.

This research topic has been in the field for 20-25 years. What’s the evolution of this topic? What has now become much more of a problem, what has affected these groups much more? Obviously, technology is much prominent nowadays in communities.

It’s always easy to say that we haven’t quite cracked what causes death, right? In the last few decades we’ve found quite a lot of things that don’t seem to cause mental disorders.

What we have settled on is that there seems to be two things: traumatic migration experience; refugees have higher risk of disorder than economic migrants. Second, the pre- and post-migratory social context, for example, people’s loss of social status—when people go from a good job to being a cleaner after migration.

I’m wondering, but I fear the answer, if there is a country that has policies around the health issues of migrants that have contributed to healthier communities?

There are countries where there’s not such a big increase in mental disorders. Canada is one of them, but part of that is because Canada has a really strict migration policy. The people that Canada gets in tend to be people with quite high socioeconomic status and quite highly skilled. You’d expect them to have not such a high instance [for psychosis]. The other country, interestingly, is Israel. Quite often people who migrate to Israel go from a position of exclusion to a position of inclusion. Then, even Israel, because there is quite a lot of migrants from the Horn of Africa, have an increased risk of mental disorder.

I don’t think there is a country that’s doing spectacularly well in this respect, I am afraid.

Why did you make this subject your study? Why is this important to you?

To me, it is important, because there is no obvious reason why one particular ethnic group should have an increased risk. It differs per country what particular minority population is affected by mental disorder. What got me thinking were the Moroccans in the Netherlands and black Caribbean people in the UK. It also happens to be the groups that society point to, if something in society goes wrong—in the UK that has been shifting towards Muslims. That’s what got me interested, is there some kind of relationship between how we view certain minority groups and their mental health?