Institute of Medical Psychology

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Shift Work

Project leader: Dr. Céline Vetter

celinevetterAlleviating the detrimental effects inherent to working in shifts represents one of the most prominent issues in the field of work-time management. Sixty percent of the general population suffers from a discrepancy between body clock and social clock (social jetlag), but shift-workers are exposed to the most extreme form of this modern syndrome. Shift-work research is therefore an excellent basis to identify and understand the consequences of social jetlag in work-time settings. The circadian clock modulates physiology, cognition, metabolism and behaviour; internal time (the time produced by our body clock) rather than social time (as shown on our clocks and watches) is therefore the adequate basis to understand the consequences of living against the body clock.

While 9 a.m. might mean lunch-time for a very early chronotype, it may correspond to the end of the biological night for a very late type. While the physiology of an early type will be drastically affected in a night shift, late types will suffer more during early shifts. Thus, innovative work schedules have to consider chronotype as one of the mediators for health, wellbeing, and safety. 

The first circadian-oriented work schedules were successfully implemented in the 70s; yet, increasing evidence shows that individual biological time (i.e., chronotype) has a major impact on sleep, metabolism, and cognition dependent on work schedules and social constraints.

The shift-work group aims at increasing working time flexibility thereby decreasing social jetlag, optimising sleep duration and quality, resulting in improved living conditions. Since light is the most potent signal to set circadian clocks, we also devise and evaluate strategies on how to use light (spectral composition, light intensities, exposure time) to alleviate the adverse effects of shift-work schedules.

While we are currently focussing on understanding the effects of shift-work on different chronotypes, any work-schedule is potentially on the test bench for improvement, i.e., for adjusting work to individual biology and vice versa. People who can sleep according to their individual biological time are more efficient, more content and healthier both at work and during their free time.

Our methods, i.e., the integration of circadian principals and the notion of individuality in circadian timing, are always adapted to social and production/managerial constraints.


  • Prof. Dr. Till Roenneberg
  • Dorothee Fischer (Dipl.-Psych., Psychology), PhD Student
  • Joana Mehlmann (B.Sc., M.Sc., Biology & Business Administration), PhD Student
  • Alexandra Bader (cand. Dr. med), Research assistent
  • Tina Egger (cand. Dr. med), Research assistent


  • Dr. Myriam Juda (University of British Columbia, CA)
  • Dr. Thomas Kantermann (University of Gronigen, NL)

Former Projects

Recent Publications

  • Vetter C, Juda M, & Roenneberg T (in press) The influence of internal time, time awake and sleep duration on cognitive performance in shiftworkers, Chronobiology International
  • Roennebert T, Allebrandt KV, Merrow M, & Vetter C (2012) Social Jetlag and Obesity, Current Biology 22(10), 939-943.
  • Vetter C, Juda M, Lang D, Wojtysiak A, Roenneberg T (2011) Blue-enriched office light competes with natural light as a zeitgeber Scandinavian Journal of Work, Environment and Health 37(5), 437-444.
  • Kantermann T, Juda M, Vetter C, Roenneberg T (2010) Shift-work research: where do we stand, where should we go? Sleep and Biological Rhythms 8(2), 95-105
  • Blautzik J, Vetter C, Peres I, Gutyrchik E, Keeser D, Berman A, Kirsch V, Mueller S, Pöppel E, Reiser M, Roenneberg T, Meindl T.Classifying fMRI-derived resting-state connectivity patterns according to their daily rhythmicity.Neuroimage. 2013 May 1;71:298-306
  • Juda, Myriam, Vetter, Céline, & Roenneberg, Till:The Munich ChronoType Questionnaire for Shift-Workers (MCTQShift), J Biol Rhythms April 2013 vol. 28 no. 2 130-140