Clinical symptoms of psychotic episodes and 25-hydroxy vitamin D serum levels in black first-generation immigrants
- Preliminary results were in an oral presentation: ‘Does a recently occurred vitamin D deficit explain the excess of psychosis and schizophrenia in black first-generation immigrants?’ at the symposium: ‘What explains the schizophrenia epidemic among immigrants to Western Europe?’ organized by Jean-Paul Selten and Wim Veling, with John McGrath as discussant, at the 3rd Biennal Schizophrenia International Research Society Conference, Florence, Italy, April 14-18, 2012.
Dark-skinned immigrants have a higher risk for schizophrenia and other psychoses than other immigrants. The first British studies reported that first-generation immigrants (FGIs) from the Caribbean presented atypical psychoses. This study examines the characteristics of psychotic episodes in black FGIs to Canada.
The charts of 18 FGIs from Africa and Haiti, extracted from a series of 20 black patients consecutively admitted to Psychiatry, were retrospectively reviewed regarding clinical features, diagnoses and vitamin D levels.
Young FGIs presented acute psychotic episodes with abrupt onset, florid positive symptoms, few negative symptoms and good evolution. The onset was more insidious in older FGIs. Overall, catatonia was very frequent (28%), and mood symptoms still more frequent (44%). No cognitive decline was observed during follow-up. Serum levels of 25-hydroxy vitamin D were in the insufficiency range. Supplementation at 1000 IU/day did not restore normal levels.
The clinical features of psychotic episodes in black FGIs are similar to those reported in dark-skinned FGIs to other countries. They are also observed in other immigrants and in non-immigrants. These atypical psychoses are possibly related to a recent vitamin D deficit. This hypothesis should be tested by clinical trials of sufficient vitamin D supplementation.