The world’s leading experts on schizophrenia are gathered in Oulu this week to debate an illness which blights Finland more than its neighbours.

Schizophrenia experts from around the world have descended on Hotel Lasaretti for a major conference on the debilitating mental illness. Entitled ‘Schizophrenia: Epidemiology and Biology,’ many have travelled from as far as Australia, the USA and New Zealand to present cutting edge research into the causes of the condition, which is estimated to effect about 4 percent of people in Europe.

Characterised by delusions, hallucinations and a general breakdown in though processes, schizophrenia actually has a great prevalence in Finland – notably in certain rural areas – than in other European countries. But if one of the leading presenters at the conference is to believed levels of the condition in Finland are only set to increase.

According to Prof. Peter Jones, of the UK’s Cambridge University, there is clear evidence from England that two environmental factors explain differences in schizophrenia to a significant extent: cannabis and migration.

Research by Jones and his team has found the ‘visible migrants’ in the UK are far more prone to developing schizophrenia than the host population. Turning to northern Finland, he predicts that if migration into the area increases, levels of schizophrenia are likely to follow.

Quite why this is the case is still under debate. However, Jones suggests two possibilities. Firstly, new immigrants into an area often experience discrimination and are treated poorly. This trauma, he suggests, may lead to a rise in schizophrenia because stress seems to trigger psychotic episodes. Alternatively, it may be that a lower ability to absorb Vitamin D from the sun, caused by having darker skin in an environment with lower levels of sunlight, may also, somehow, be triggering the disorder.

He suggested to 65DN that the first explanation may explain high levels of schizophrenia even amongst native Finns.

‘It is not migration per se that explains the difference but this interacting with genes in certain individuals,’ he said. ‘It is also more likely to develop amongst people living long distances from others in isolated communities with a lack of social networks.’

It was ‘possible’ that immigrants were more likely than those they left behind to be creative. Anthony Ahmed, of George University of Medical Sciences, told 65DN that creativity was related to a psychological trait known as ‘schizotypy’ which is, in effect, on a spectrum towards schizophrenia and includes aspects of schizophrenia such as unusual though processes or mental experiences. However, Prof. Jones emphasised that immigrants often tend to be healthier, both physically and mentally, than those they leave behind, which would imply that being an immigrant is what leads to schizophrenia.

The other factor which Jones’ England-based research emphasised was the use of cannabis, and especially the industrially enhanced form of cannabis known as skunk. Eliminating other factors which might lead to schizophrenia, he found a robust connection between people using this drug – especially during adolescence – and later psychotic episodes.

‘Skunk seems to be less of a problem in England than it is Finland,’ he said, but noted that skunk has been spreading from Australia to the UK and is likely to reach Finland at some point. And when it does, he predicts, levels of schizophrenia are likely to rise.

However, not all researchers on schizophrenia are so sure about the importance of environmental factors.

Prof. Jim Van Os, of Maastricht University in the Netherlands, for example, was less sure about the common belief that Finland has higher schizophrenia levels at all.

‘The statistics are based on clinical diagnosis but contact with the healthcare services which is not a good measure of schizophrenia in a population,’ he told 65DN. ‘We need to consider untreated schizophrenia.’ He added that people in Finland may simply be more able to seek medical help for mental illness than in surrounding countries.

And many researchers at the conference stressed the strong genetic element to schizophrenia. Experiments by Holland’s Prof Inez Myins-Germeys, of Maastricht University, found that variation in a particular gene strongly explained whether or not a person would develop delusions when placed under stress. According to the researcher, those with one form of the gene responded in a ‘normal’ fashion to stress while those with another developed symptoms of schizophrenia. Those with a third variant responded normally to stress but developed symptoms of schizophrenia upon taking strong cannabis.

The apparent susceptibility of immigrants to schizophrenia is strong that Dr Atiqul Haq Muzumder, of Dhaka in Bangladesh, suggested that the only way to avoid it was to ignore feelings of discrimination and ‘be like Vikings,’ treating being abroad as an ‘adventure.’