A survey of almost 3,000 people in Brazil who have experienced first-episode psychosis has found that young men, ethnic minorities and people living in socioeconomically disadvantaged areas are more likely to suffer from the common symptoms.
First-episode psychosis is defined as the first manifestation of one or more severe mental disorders including bipolar affective disorder, schizophrenia and depression with psychotic symptoms such as delusions, hallucinations and cognitive disorganisation.
This is the finding of a study conducted by an international consortium, which estimated the incidence of first-episode psychosis in five European countries – England, Italy, the Netherlands, Spain and France – as well as Brazil.
Who are the most at risk?
Recent research has shown that in European countries these disorders have been more frequent in large cities than smaller towns or rural areas.
It is also fairly frequent amongst ethnic minorities such as black immigrants from the Caribbean and Africa.
Paulo Rossi Menezes, a professor in the Preventive Medicine Department of the University of São Paulo‘s Medical School (FM-USP), Brazil, said: “The study confirmed that the incidence of first-episode psychosis varies considerably between major cities and rural areas.
“It also showed that environmental factors probably play a crucial role in this significant variation.
“Until the end of the twentieth century, the etiology of psychotic disorders was believed to be mainly genetic, but the results of this study show that environmental factors are extremely important,” he concluded.
What else did the study find?
The study also showed that the incidence of first-episode psychosis was higher among men aged 18 to 24 than among women in the same age group.
Menezes added: “We don’t know exactly why there are these differences in incidence between sexes and age groups, but they may be linked to the process of cerebral maturation: the brain matures between the ages of 20 and 25, and during this period, men seem to be more vulnerable to mental disorders than women.”
Also, according to Menezes, traumatic childhood experiences or smoking cannabis when a teenager or young adult are factors that increase the risk of mental disorders.
He said: “If we can identify the risk factors for the development of these mental disorders in more vulnerable groups, we’ll be able to intervene to reduce their incidence.”
The results were published in JAMA Psychiatry.