Shift work sleep disorder (SWSD) belongs to a family of sleep disorders known as circadian rhythm sleep-wake disorders. Its defining clinical feature is a misalignment between an individual’s body clock and the sleep-wake schedule imposed by external factors such as a work schedule.
It can be difficult to distinguish between SWSD and other sleep disorders or, simply, occasional sleep disturbances. Sleep-related complaints are very common in people who work non-traditional shifts regularly. However, these sleep problems are not necessarily indicative of a sleep disorder.
Research shows that approximately 25% of rotating shift workers and 33% of night workers suffer from a sleep disorder as a direct consequence of their work schedule. According to the American Academy of Sleep Medicine, SWSD is characterized by excessive sleepiness during night shifts and daytime insomnia during periods allocated to sleep. People suffering from SWSD tend to get less sleep, take longer to fall asleep, and have a harder time staying asleep compared to non-shift workers.
The symptoms of SWSD are essentially a natural response of the body to external circumstances that go against our biological rhythms. Humans are a diurnal species, which means that we are biologically designed to be active during the day, with sleep occurring at night. However, for some shift workers, work overlaps with this natural sleep period. This means that the body receives a powerful sleepiness signal at night, during work hours when alertness and productivity are much more important than sleep. Then, during daytime hours, which may be a shift worker’s only opportunity for sleep, the body receives alertness signals.
Other factors may further contribute to sleep issues in shift workers. For example, night workers often do not spend as much time as they wish with family and friends due to conflicting personal lives and work schedules. This can understandably lead to social isolation, elevated stress, and low mood.
Studies show that working non-traditional or irregular hours can have various physical and psychological effects. For instance, shift workers are at increased risk of developing chronic health conditions, including obesity, insulin resistance, heart disease, gastrointestinal disorders, and metabolic and hormonal imbalances. Shift workers are also at greater risk of experiencing anxiety, depression, and elevated stress. Some of these mental health effects may further contribute to sleep problems. For instance, anxiety and preoccupations about poor sleep are among the greatest enemies of sleep, creating a vicious cycle.
In addition to its health effects, SWSD is associated with important public health issues. It generates high financial costs for society, attributed largely to absenteeism and low productivity in the workplace. It also increases the risk of workplace injuries and vehicle accidents, both of which carry potentially fatal consequences.
If your work schedule is negatively impacting your sleep and you are unable to make a change toward a more traditional work schedule, there are evidence-based solutions that can help. Cognitive behavioural therapy for insomnia, or CBT-I for short, has been shown to be effective for shift work sleep disorder. At HALEO, we have adapted our CBT-I program to help individuals suffering from SWSD, so that you can regain better sleep and minimize the effects of shift work on your health and well-being.
Read more: Napping Tips for Night Workers and Shift Workers