Associations Between Social Capital and Depressive Symptoms Among College Students in 12 Countries: Results of a Cross-National Study.

INTRODUCTION: A mental health crisis has hit university campuses across the world. This study sought to determine the prevalence and social determinants of depressive symptoms among university students in twelve countries. Particular focus was placed on the association between social capital and depressive symptoms. METHODS: A cross-sectional study was conducted among students at their first year at university in Europe, Asia, the Western Pacific, and Latin and North America. Data were obtained through a self-administered questionnaire, including questions on sociodemographic characteristics, depressive symptoms, and social capital. The simplified Beck's Depression Inventory was used to measure the severity of depressive symptoms. Social capital was assessed using items drawn from the World Bank Integrated Questionnaire to Measure Social Capital. Multilevel analyses were conducted to determine the relationship between social capital and depressive symptoms, adjusting for individual covariates (e.g., perceived stress) and country-level characteristics (e.g., economic development). RESULTS: Among 4228 students, 48% presented clinically relevant depressive symptoms. Lower levels of cognitive (OR: 1.82, 95% CI: 1.44-2.29) and behavioral social capital (OR: 1.51, 95% CI: 1.29-1.76) were significantly associated with depressive symptoms. The likelihood of having depressive symptoms was also significantly higher among those living in regions with lower levels of social capital. CONCLUSION: The study demonstrates that lower levels of individual and macro-level social capital contribute to clinically relevant depressive symptoms among university students. Increasing social capital may mitigate depressive symptoms in college students.

Long-term exposure to high temperature associated with the incidence of major depressive disorder.

Temperature was reported to have acute effects on mental disorders. However, the effect of long-term temperature exposure is unclear, especially in warmer regions. This research aimed to evaluate the association between long-term exposure to temperature and the incidence of major depressive disorder (MDD). A retrospective population-based study was conducted using Taiwan nationwide Longitudinal Health Insurance Database 2005. Subjects without MDD diagnosis were followed from 2003 to 2013 for MDD occurrence. Weather factors including temperature (°C), sunshine duration (hrs/day), and precipitation (mm/day) were 11-year average of daily data collected from weather monitoring stations of Taiwan Central Weather Bureau. Cox proportional hazard model was performed to examine the association between MDD incidence and weather factors. Covariates including age, gender, and insurance amount were adjusted. A total of 9,539,752 person-years were followed. People residing in regions with long-term temperature of 20-23 °C had the lowest risk of developing MDD. Risk for MDD incidence was higher among residents in regions with average temperature > 23 °C, at 7% increase per 1 °C increment (95% CI = 2-12%). The elderly was more vulnerable to such impact of heat exposure. For the elderly, males were more susceptible to heat-related MDD than females (HR = 1.18 vs. 1.14). However, the younger group showed a reverse finding (i.e. females 1.07 > males 1.04). Long-term residence in regions with extreme cold or heat may increase the risk of MDD incidence, especially higher temperature. Under global warming, these findings have great health implications and warrant further confirmation.

Microfluidic chip for plasma separation from undiluted human whole blood samples using low voltage contactless dielectrophoresis and capillary force.

A plasma separating biochip is demonstrated using a capillary-driven contactless dielectrophoresis method with low voltage (~1 V) and high frequency induced electrostatics between red blood cells. The polarized red blood cells were aggregated and separated from plasma with a 69.8% volume separation and an 89.4% removal rate of red blood cells.