Effect of Bright Light Therapy on Depressive Symptoms in Middle-Aged and Older Patients Receiving Long-Term Hemodialysis

Depressive symptoms are common psychiatric comorbidities among individuals receiving long-term hemodialysis. The aim of this two-arm parallel design study is to assess the effects of bright light therapy (BLT) on depressive symptoms among middle-aged and older adults receiving long-term hemodialysis. Study participants are recruited using convenient sampling from four dialysis clinics in eastern Taiwan. The eligible participants are block-randomized to either the BLT group (n = 30), with 30 min sessions of BLT five times a week for six weeks at their own home, or to the routine care control group (n = 30). The Beck Depression Inventory-II (BDI-II) scores and the salivary cortisol levels are obtained from the participants at three time points: baseline (T0), week 3 (T1), and week 6 (T2). The results, from the generalized estimating equations, indicate that the decline in the BDI-II scores over time is significant in the BLT group at T1 (β = −7.57, p < 0.001) and at T2 (β = −6.20, p = 0.002) compared to the control group. The decrease in salivary cortisol levels at each visit is also significant in the BLT group at T1 (β = −7.37, p = 0.017) and at T2 (β = −12.22, p = 0.005) compared to the control group. Our findings support the hypothesis that a six-week program of BLT is able to alleviate depressive symptoms in middle-aged and older patients who receive long-term hemodialysis.