Association between solar insolation and a history of suicide attempts in bipolar I disorder

In many international studies, rates of completed suicide and suicide attempts have a seasonal pattern that peaks in spring or summer. This exploratory study investigated the association between solar insolation and a history of suicide attempt in patients with bipolar I disorder. Solar insolation is the amount of electromagnetic energy from the Sun striking a surface area on Earth. Data were collected previously from 5536 patients with bipolar I disorder at 50 collection sites in 32 countries at a wide range of latitudes in both hemispheres. Suicide related data were available for 3365 patients from 310 onset locations in 51 countries. 1047 (31.1%) had a history of suicide attempt. There was a significant inverse association between a history of suicide attempt and the ratio of mean winter solar insolation/mean summer solar insolation. This ratio is smallest near the poles where the winter insolation is very small compared to the summer insolation. This ratio is largest near the equator where there is relatively little variation in the insolation over the year. Other variables in the model that were positively associated with suicide attempt were being female, a history of alcohol or substance abuse, and being in a younger birth cohort. Living in a country with a state-sponsored religion decreased the association. (All estimated coefficients p <0.01). In summary, living in locations with large changes in solar insolation between winter and summer may be associated with increased suicide attempts in patients with bipolar disorder. Further investigation of the impacts of solar insolation on the course of bipolar disorder is needed.Peer reviewe

Abnormalities in the migration of neural precursor cells in familial bipolar disorder

Cellular migration is a ubiquitous feature that brings brain cells into appropriate spatial relationships over time; and it helps in the formation of a functional brain. We studied the migration patterns of induced pluripotent stem cell-derived neural precursor cells (NPCs) from individuals with familial bipolar disorder (BD) in comparison with healthy controls. The BD patients also had morphological brain abnormalities evident on magnetic resonance imaging. Time-lapse analysis of migrating cells was performed, through which we were able to identify several parameters that were abnormal in cellular migration, including the speed and directionality of NPCs. We also performed transcriptomic analysis to probe the mechanisms behind the aberrant cellular phenotype identified. Our analysis showed the downregulation of a network of genes, centering on EGF/ERBB proteins. The present findings indicate that collective, systemic dysregulation may produce the aberrant cellular phenotype, which could contribute to the functional and structural changes in the brain reported for bipolar disorder. This article has an associated First Person interview with the first author of the paper

Novel infectious agents causing uveitis

10.1007/s10792-009-9319-6International Ophthalmology1-1

Exploratory study of ultraviolet B (UVB) radiation and age of onset of bipolar disorder

Peer reviewe