Association between Ultraviolet B Exposure Levels and Depression in Taiwanese Adults: A Nested Case–Control Study

Abstract

Depression is a common mental disorder that affects more than 264 million people worldwide. Anxiety, diabetes, Alzheimer’s disease, myocardial infarction, and cancer, among other disorders, are known to increase the risk of depression. Exposure to ultraviolet B (UVB) can cause human serotonin levels to increase. The vitamin D pathway is one mechanism through which ultraviolet light absorbed through the skin can affect mood; however, UVB exposure is known to increase the risk of cancer. In this study, we explored the effects of prolonged exposure to UVB on depression. Data were retrieved from the Taiwan National Health Insurance Research Database for 2008 to 2013. Each patient with depression was matched 1:4 with a comparison patient by sex and age (±5 years); thus, the study included 23,579 patients with depression and 94,316 healthy controls for comparison. The patients had been exposed to UVB for at least 1 year to observe the cumulative effect of UVB exposure. Based on the World Health Organization UV index, we divided the observation period data into five UV levels: low, moderate, high, very high, and extreme. A multivariate Poisson regression model was used to assess the risk of depression according to UVB exposure level, adjusting for sex, age, income, urbanization level, month, and comorbidities. The results revealed that the incidence rate ratio (IRR) for patients with depression was 0.889 for moderate levels (95% CI 0.835–0.947), 1.134 for high levels (95% CI: 1.022–1.260), 1.711 for very high levels (95% CI: 1.505–1.945), and 2.785 for extreme levels (95% CI: 2.439–3.180) when compared to low levels. Moderate levels of UVB lowered the risk of depression, while high levels of UVB gradually increased the risk. We propose that UVB at normal concentrations can effectively improve depression. However, exposure to high concentrations of UVB damage DNA results in physical diseases such as skin cancer, which increase the risk of depression.

Comparing the Evidence from Observational Studies and Randomized Controlled Trials for Nonskeletal Health Effects of Vitamin D

“…Vitamin D also modulates concentrations of gut microbiota, reducing bacterially induced activation of NF-κB in the intestine, thereby reducing remote inflammation further [153]. A nested case-control study conducted in Taiwan indicated that although moderate UVB exposure reduced risk of depression, high UVB exposure increased this risk [157]. The adjusted incidence rate ratio for moderate versus low UVB exposure was 0.89 (95% CI, 0.84-0.95); for high UVB, 1.12 (95% CI, 1.02-1.26); for very high UVB, 1.71 (95% CI, 1.51-1.95); and for extreme UVB, 2.79 (95% CI, 2.…”

Association Between Sunlight Exposure and Mental Health: Evidence from a Special Population Without Sunlight in Work

“…A study demonstrated that long-term exposure to moderate levels of ultraviolet B can inhibit the development of depression in Taiwan, China. 12 Besides, light therapy is effective in treating seasonal affective disorder as well as non-seasonal depression. 13 , 14 Another study also found that mental illnesses patients living in rooms with better sunlight tend to have shorter hospital stays.…”

“…Firstly, previous studies have focused on patients with mental disorders, such as depression, 12 schizophrenia 16 and have lacked exploration of the general community population. Secondly, many of these previous studies were ecological studies of the population and presented sunlight through objective meteorological data, 12 , 17 , 21 , 22 such as daytime sunshine hours and ultraviolet (UV) index.…”

“…Firstly, previous studies have focused on patients with mental disorders, such as depression, 12 schizophrenia 16 and have lacked exploration of the general community population. Secondly, many of these previous studies were ecological studies of the population and presented sunlight through objective meteorological data, 12 , 17 , 21 , 22 such as daytime sunshine hours and ultraviolet (UV) index. This neglected the characteristics of sunlight; regional sunlight data do not represent an individuals’ actual receiving sunlight; rather, it is closely related to their living environment and habits.…”

Organic Synthesis of New Secosteroids from Fucosterol, Its Intestinal Absorption by Caco-2 Cells, and Simulation of the Biological Activities of Vitamin D

“…Vitamin D plays a multi-faceted role in human health. Specifically, its blood levels are associated with a range of health conditions and risks, including maternal and child health [3,4], reproductive functions [5][6][7], physical performance [8], renal function [9], and sleep quality [10], as well as diseases like cancer [11][12][13][14], lung disease [15][16][17][18][19], vascular disease [20][21][22], metabolic syndrome [23,24], dementia [25,26], psychiatric disorders [27][28][29][30], viral diseases [31][32][33][34][35] including COVID-19, and intractable diseases like myofibromyalgia [36]. Furthermore, adequate vitamin D levels can reduce chronic inflammation, a known trigger for various serious diseases [37,38].…”