Study finds that working in shifts can cause depression

Research published in the journal JAMA Network Open reveals that individuals employed in shift work face a 22% higher likelihood of developing depression compared to those with regular daytime schedules. The study also identifies a 16% increased risk of anxiety among shift workers. In this context, shift work is defined as job schedules that deviate from the typical 9am to 5pm, encompassing evening or night shifts and potentially involving rotating schedules.

These findings stem from an analysis of employment and health data involving 175,543 participants, predominantly middle-aged, monitored over approximately a decade. This cohort included nearly 28,000 individuals engaged in shift work. Throughout the study period, approximately 2% of the workers were diagnosed with depression, and a similar percentage developed anxiety. Shift workers were shown to have a heightened likelihood of experiencing both conditions.

The study also highlights that the risk level is more pronounced among those who are newly exposed to shift work. A separate study, focusing on the health implications of shift work and published in the journal PLOS ONE, reported elevated rates of cognitive impairment among middle-aged and older adults engaged in night shifts or rotating shifts. This study identified detrimental effects on shift workers’ memory and executive function, encompassing planning, decision-making, and organisational abilities.

The research suggests that the disruption of shift workers’ circadian rhythms, which regulate the body’s natural sleep-wake cycle, contributes at least partially to these adverse outcomes.

Furthermore, the JAMA study proposes that the connection between shift work and depression and anxiety may be “partially explained” by lifestyle factors such as smoking, sleep duration, and sedentary behaviour. The researchers conclude that their study supports the notion that shift work should be regarded as an occupational hazard.