Shift work disorder (SWD) results from circadian misalignment, where the internal circadian clock fails to synchronize with external changes induced by shift work. The prevalence of SWD ranges from 2.3% to 84.0%, depending on shift type, occupation, and measurement methods [1].Currently, SWD treatments include medications or nonpharmacologic treatments to normalize the circadian cycle or alleviate symptoms like excessive sleepiness or insomnia. However, there are no treatments, whether pharmacologic or nonpharmacologic, that can completely restore altered circadian cycles to their baseline levels.This opinion outlines diverse adaptive strategies and therapeutic approaches for sleep disturbances developed in our research laboratory.
Pharmacological InterventionLimited evidence supports melatonin's efficacy in improving sleep duration after a night shift, with no impact on other sleep quality parameters [2]. Modafinil and armodafinil enhance alertness and reduce sleepiness in individuals with SWD; however, they are associated with adverse events. The combination of caffeine and naps decreases sleepiness during night shifts, though evidence quality is deemed low. Conversely, sedative-hypnotics show no improvements in sleep duration or quality after a night shift. The variability in shift schedules, melatonin dosage, and timing makes it challenging to draw definitive conclusions.So far, there is no satisfying pharmacological intervention for SWD, emphasizing the need for more advanced experimental designs considering the environmental factors of shift workers.
Bright Light TherapySimulation studies and a few field studies suggest that daylight or bright light exposure in the early morning can inhibit adaptative circadian phase resetting. In addition, the use of dark goggles was also shown to successfully inhibit phase resetting [3].However, relying solely on bright light therapy to normalize circadian rhythms disruption resulting from changing shift work is ineffective. Coordinating light therapy and melatonin with the shift work cycle is essential. Recommendations include adjusting shift work cycles, providing 4-5 days off between day and night shifts, incorporating light therapy, light restriction, and sleep timing adjustments to gradually shift the sleep phase. This complex approach, combining bright light therapy and chronotherapy, appears more effective. However, implementing such schedules requires more holidays, and increasing workforce,