A new study released by the BMJ medical journal has said that migrants suffer from mental illnesses like paranoid schizophrenia, psychotic disorders and depression at far higher rates than their Swedish counterparts.

Sweden’s Karolinska Institute and University College London used information obtained from 1.3 million teenagers by the Swedish national register who kept track of them for 13 years, reports The Local. The sample group was split into Swedish born citizens with Swedish parents, asylum seekers, and migrants from the Middle East, North Africa, Southern Africa, Asia and Eastern Europe.

In every 10,000 migrants they found that 12 or so exhibited signs of schizophrenia or suffered from psychotic episodes compared to only 4 in 10,000 for native Swedes.

Anna-Clara Hollander, who heads the study for the Karolinksa’s Department of Health said, “the dramatically increased risk among refugees shows that life events are a significant risk factor for schizophrenia.”

Another separate study of 15 year-olds also saw a dramatic rise in mental illness. The study by the World Health Organization states that Swedish 15 year-old children have the highest rate of mental illness of anywhere in Europe, and they also have one of the the lowest rates of alcohol and cigarette use.

Swedish boys who say that they drink alcohol at least once a week fell 9.5 pe rcent from 2010 to 2014 and the figures were even more dramatic for girls who saw an 11.4 per cent decrease in alcohol consumption. The figures have made Sweden one of the five countries with the lowest alcohol use among teens.

Other Scandinavian countries have followed a similar trend in regards to drinking among teens but Sweden, it is said, is the only one to see a spike in mental illness.

In 2010 Sweden had an average rate of mental illness rating at about 19th out of 39 countries studied. In 2014 Sweden was rated 8th out of 42 countries studied. The other Nordic countries, Norway, Denmark and Finland are the opposite and rank among the five countries with the lowest rates of mental illness.