Shift workers are required to be awake and alert, often at times when the circadian clock is in its incompatible nighttime mode.  The ensuing lack of alertness can spell danger—on the road, operating machinery, prescribing medications in the emergency room, and so on.  Some people are more tolerant to shift work than others.  A night owl, for example, will adjust more easily than a lark to the night shift.  Switching across shifts, or alternating days off with shiftwork, presents a formidable challenge to the circadian timing system.

Research focuses on methods to expedite adjustment to the shifts—or at least partial adjustment that allows sufficient recovery sleep to maintain functionality.  There is no magic bullet, however.  We weren’t built for shift work—it is an artifice of the competitive post-industrial age, inherently dangerous to workers’ health.

REFERENCES

Reviews

Cole RJ, Loving RT, Kripke DF. Psychiatric aspects of shiftwork. Occupational Medicine: State of the Art Reviews 1990;5:301-314.
Eastman CI, Boulos Z, Terman M, Campbell SS, Dijk D-J, Lewy AJ. Light treatment for sleep disorders:  Consensus report. VI. Shift work. Journal of Biological Rhythms 1995;10:257-264.
Monk TH. What can the chronobiologist do to help the shift worker? Journal of Biological Rhythms. 2000;15:86-94.
Akerstedt T, Wright KP Jr. Sleep loss and fatigue in shift work and shift work disorder. Sleep Medicine Clinics 2009;4:257-271.
Monk TH, Buysse DJ, Billy BD, Fletcher ME, Kennedy KS, Begley AE, Schlarb JE, Beach SR. Shiftworkers report worse sleep than day.

Studies

Czeisler CA, Johnson MP, Duffy JF, Brown EN, Ronda JM, Kronauer RE. Exposure to bright light and darkness to treat physiologic maladaptation to night work. New England Journal of Medicine 1990;322:1253-1259.
Crowley SJ, Lee C, Tseng CY, Fogg LF, Eastman CI. Combinations of bright light, scheduled dark, sunglasses, and melatonin to facilitate circadian entrainment to night shift work. Journal of Biological Rhythms 2003;18:513-523.