Evaluation of the Effect of Light Therapy on the Evolution of Self-reported Depressive Disorders in Chronic Hemodialysis Patients

In France, the prevalence of end-stage chronic kidney disease has been increasing for several years. Chronic hemodialysis constitutes an essential renal replacement therapy but imposes a constrained lifestyle due to recurrent sessions at the dialysis center. It is frequently accompanied by a deterioration in quality of life reported by patients and a high prevalence of depressive syndromes, estimated to be between 22% and 68%. Despite this high frequency, the systematic screening of depressive symptoms is not uniformly integrated into the routine practice of dialysis centers, and there are no specific recommendations regarding the psychiatric management of dialysis patients. However, the Haute Autorité de Santé 2023 recommendations emphasize the importance of regular evaluation of quality of life and psychological burden in these patients using standardized tools. Dialysis patients often exhibit disorganization of circadian rhythms, including alterations in melatonin production, accompanied by disturbances in the cortisol cycle (reduced pulsatility and daily overexposure). This disorganization of the cortisol cycle is also observed in depressive states. These circadian disturbances are often targeted by antidepressant treatments or by non-pharmacological approaches such as light therapy. Light therapy is an intervention based on exposure to high-intensity white light (generally greater than 5000 Lux), preferably administered in the morning for approximately 30 minutes. It aims to resynchronize circadian rhythms, particularly through modulation of melatonin secretion. It has demonstrated efficacy on depressive symptoms in the general population, but few studies have evaluated its use in patients with renal failure. A randomized trial showed a reduction in the Depression Anxiety and Stress Scale 21 (DASS-21) score in the light therapy group. An open-label study reported a significant decrease in depressive symptoms assessed by the Beck Depression Inventory-II (BDI-II). However, these studies have methodological limitations and did not evaluate a treatment regimen specifically adapted to the rhythm of hemodialysis sessions (three mornings or afternoons per week). In 2024, our pilot study LUMIDIAL-1 reported a trend toward decreased depressive states in hemodialysis patients exposed to light therapy, also confirming feasibility under real dialysis conditions. These preliminary results justify the establishment of a multicenter, randomized, controlled trial with a sham comparator and enhanced blinding to rigorously evaluate the efficacy of light therapy in chronic hemodialysis patients with depressive symptoms. The coordinating investigator and the methodologist hypothesize that, in chronic hemodialysis patients presenting with self-reported depressive symptoms defined by a score ≥ 8 on the depression component of the Hospital Anxiety and Depression Scale (HADS-D), light therapy could reduce the intensity of depressive symptoms by contributing to the restoration of the melatonin and cortisol cycles. In the long term, this non-pharmacological intervention could improve quality of life and decrease reliance on psychotropic treatments.