Scientists have identified groups of people at increased risk of developing serious mental disorders by conducting a multinational study in six countries around the world. It turned out that young men (up to 24 years), ethnic minorities, and people living in socially and economically disadvantaged areas are more likely to experience one or more severe mental disorders, including schizophrenia, bipolar affective disorder, and depression with psychotic symptoms , such as hallucinations, delusions and cognitive disorganization.

This is the main conclusion of the study conducted by an international consortium that estimated the frequency of the first psychotic episode in five European countries - England, France, Italy, the Netherlands and Spain, as well as in Brazil. The results were published in JAMA Psychiatry.

Studies in recent years have shown that the frequency of the first psychotic episode varies depending on the regions and population groups. In European countries, these disorders are more common in large cities than in small settlements or rural areas. In addition, such cases are often found among ethnic minorities, such as black migrants from the Caribbean and Africa. The Consortium of Scientists decided to confirm or disprove these observations through a study conducted in 17 urban and rural areas in six countries between 2010 and 2015.

For the beginnings they have revealed 2774 persons with suspicion on the first episode of a psychosis which addressed for psychiatric help in those areas in which there was a research. Of these, 1,578 were men, and 1,196 were women. Their average age was 30 years. The analysis of the data showed eight-fold discrepancies in the frequency of the first episode of psychosis in the surveyed areas. Thus, in Santiago, Spain, 6 new cases per 100,000 inhabitants per year were identified, in Paris, France - 46 per 100,000, and in Ribeirao Preto, Brazil - 21 cases.

The study also showed that the frequency of the first episode of psychosis was higher among men aged 18 to 24 than among women in the same age group. This discovery confirms previously published data. But as we approach the age of 35, the data for men and women gradually equalize. At the same time in women aged 45-54 years the probability of the first episode of psychosis is slightly higher than among men in the same age group.

"We do not know exactly why there are these differences between the sexes and age groups, but they can be related to the process of brain maturation: the brain ripens between the ages of 20 and 25, and during this period, men appear to be more vulnerable to mental disorders than women, "said Paulo Menezes.

Researchers also found that the frequency of the first episode of psychosis is high among ethnic minorities, as well as among residents of disadvantaged areas.

In this case, traumatic childhood experiences or smoking in adolescence were factors that increase the risk of mental disorders.

"This suggests that the socio-economic conditions and the environment in which people live, play an important role in the etiology of mental disorders. Now we need to better understand the mechanisms that cause differences between population groups. If we can identify the risk factors for developing these mental disorders in more vulnerable groups, we can intervene to reduce the incidence, "Menezes concluded..