Circadian-Based New Technologies for Night Workers.

Abstract

Night work is becoming increasingly common. Unfortunately, humans are physiologically unsuited to inverted schedules, leading to negative consequences for shift workers, employers, and society. The circadian and homeostatic processes which govern sleepiness and alertness are improperly aligned for night workers. We review a number of laboratory studies designed to treat circadian maladaptation to night work by shifting the circadian clock with light, exercise, or melatonin. There is substantial evidence that bright light treatments can successfully overcome the circadian misalignments associated with night work. The evidence for the efficacy of non-photic synchronizers such as exercise and exogenous melatonin is equivocal. Nevertheless, our expanding scientific understanding of the nature of the problem has generated a promising range of options for shift workers.

What Keeps Us Awake?—the Role of Clocks and Hourglasses, Light, and Melatonin

“…However, despite the fact that scheduled bright light and darkness can phase shift the circadian clocks of night workers for complete adaptation to a night work with day sleep schedule, few night workers would rather be out of phase with the diurnal world on their days off. Similarly in other situations, such as rapidly rotating shifts and the normal office environment, it is more appealing to time light exposures toward improving alertness without phase shifting (Horowitz and Tanigawa, 2002). However, given that there is no dead zone for phase shifting the circadian system in humans (Khalsa et al, 2003), it is not conceivable to enhance alertness with light without affecting circadian phase.…”

Appreciation of localised task lighting in shift work—A field study in the food industry

“…Depending on the time, bright light affects the human rhythms in different ways. In principle, strong light in the late evening will delay the circadian rhythm so that workers are better able to adapt for the night shift (Horowittz and Tanigava, 2002).…”

Bright-Light Therapy in the Treatment of Mood Disorders

“…Since then, a remarkable number of studies have been able to prove the relevance of BLT in the treatment of seasonal and nonseasonal mood disorders. Moreover, BLT was also investigated in other problems and disorders associated with circadian rhythm disturbances (jet lag, shift work or dementia) [2][3][4][5] , sleep disorders [6,7] , bulimia nervosa [8][9][10][11] and adult attention-deficit/hyperactivity disorder [12] . The purpose of this article is to give an overview on up-to-date chronobiology research, and to try to elucidate the links that exist between basic and clinical aspects relevant to light treatment in psychiatry.…”