In our current world, working from 9 until 5 o’clock is almost the exception rather than the rule. 20% of the working adults, the so-called shift workers, work outside these “regular office hours” to keep our economy going. However, what we sometimes do not realize is that these people often show a disrupted sleep-wake behavior, since their sleep pattern is not in tune with their biological sleeping pattern. This misalignment results in among others serious health effects of which Shift Work Sleep Disorder is one of them. This type of sleeping disorder is characterized by difficulties with falling asleep and staying asleep as well as sleepiness during work hours. Nevertheless, preventative or treatment options such as different drugs, light therapy, and Top-down Sleep Management (the employer and employee take care of the employee coming to work well-rested) are being explored, however, the use of these options in the clinic is still in its infancy. This article will shed light on these three options and the advantages and disadvantages that go along with them.
Before we dive into the current state of the art on how we could potentially tackle the effects of Shift Work Sleep Disorder, let me quickly walk you through how shift workers’ biological sleeping rhythm is organized and how shift work can result in misalignment of this rhythm. Our internal “watch” is orchestrated by approximately 20.000 neurons that regulate many different body functions in a 24-hour cycle. However, this watch does not stay precisely at the 24-hour rhythm and therefore must be updated continuously. Maybe you remember that going on your phone before bedtime is bad since the blue light makes it harder to fall asleep. Light is exactly what tunes this internal “watch”, more specifically it suppresses the release of melatonin, our sleeping hormone. Normally when it gets dark, the release of this sleeping hormone is less suppressed, setting the stage for sleep onset.
However, night shifts require employees to sleep during the day when it is light and your internal “watch” is tuned to promote wakefulness (daylight that suppresses the release of your sleeping hormone melatonin). Therefore, this type of sleep is fragmented (you wake up frequently and sleep for short periods of time) and of low quality, which consequently results in the build-up of a sleep debt by the employee. Furthermore, the work performed by the shift worker is during the night when wakefulness is required, however, their internal “watch” is tuned to promote sleepiness (no daylight, and therefore high levels of the sleeping hormone melatonin in the body). Logically, approximately 10 percent of shift workers have been diagnosed with Shift Work Sleep Disorder and except for the cessation of shift work, no cure for this sleep disorder is currently available. Therefore different strategies are currently being investigated that among others target this misalignment to get the sleep-wake cycle of shift workers back on track.
Nowadays, there are already different pharmacological interventions on the market for the treatment of Shift Work Sleep Disorder, the most common one being melatonin. We have already read that melatonin is our sleeping hormone, telling our body it is time to go to bed. Some studies have shown the potential for improvement of daytime sleep among shift workers when they take melatonin in the form of a pill. Therefore, the American Academy of Sleep Medicine recommends 3 milligrams of melatonin for shift workers before bed. However, studies are inconclusive about the effectiveness of melatonin pills. A review that combined multiple studies looking at the efficacy of this pharmacological intervention showed that the absolute increase in sleep efficiency was 1.9%, equal to an increase of 10 minutes in time spent sleeping. Importantly, we should bear in mind that studies that simulate the shift work environment and were able to observe the effectiveness of melatonin pills, do not reflect actual working conditions in which especially normal light (which as you have already read suppresses melatonin release by the brain and therefore promotes wakefulness) can easily override the effect of melatonin pills. This makes clinical implementation of melatonin administration in daily life for the treatment of Shift Work Sleep Disorder rather difficult at the moment.
Talking about light, you may already be familiar with different kinds of lamps currently on the market which improve alertness and help against the winter blues (a seasonal form of depression typically when the daylight hours are the shortest). Not only laboratory studies, but also field studies indicate a positive result of light therapy as a potential treatment of Shift Work Sleep Disorder. A study conducted among female nurses performing shift work during the evening/night exposed to artificial light for 30 minutes during their shift has shown to be effective in relieving sleep problems. Accordingly, a study among flight crew members replicated these results and showed that these employees' alertness was increasing. However, in order for this light therapy to be effective, a consistent format of light therapy concerning schedule, intensity, and duration should be figured out. Moreover, environmental factors such as background light or social/family responsibilities should be considered by the clinician to result in a realignment of the sleep-wake cycle of the shift worker. These limitations of light therapy are currently being explored in literature in order for clinicians to determine the appropriate timing and application of light therapy as a treatment for Shift Work Sleep Disorder.
A fairly new approach called “Top-down Sleep Management” is currently also being explored since a lot of behavior- and environmental factors hamper the effectiveness of earlier tried therapies (e.g. medication). However, I would like to point out that this “treatment” focuses on the prevention of Shift Work Sleep Disorder, rather than relieving the symptoms of a shift worker who is already diagnosed with this sleep disorder. Nonetheless, several organizational interventions show among others increased self-related health, and sleep quality which went hand in hand with decreases in absence, fatigue, and complaints about family life. One of the most important determinants of such an organizational intervention is the physical work environment. Despite for example a well-lighted workspace (here comes the importance of light back in this story), and maintenance of the right temperature, “nap rooms” are nowadays the golden standard in safety-sensitive industries (long-distance pilots). Nighttime naps where shift workers nap during work can result in a deeper sleep. Moreover, as portrayed in a study where male aircraft maintenance engineers were allowed to take a 20-minute nap at the workplace showed that this increased their alertness and performance as well as decreased their sleepiness. Another advantage of nighttime napping is the opportunity for the shift worker to sleep consistently at the same point each day, resulting in the stabilization of their sleep-wake cycle.
In conclusion, melatonin pills, and light therapy seem promising in relieving the symptoms associated with Shift Work Sleep Disorder. However, challenges remain with their implementation in real-life settings, since there is still much uncertainty about an exact dose or frequency of these therapies and in addition, translating the research results from the laboratory setting to real life does not lead to the desired results. Top-down sleep management seems then an interesting approach rather than treating this sleep disorder, to prevent it in the first place. However, to end on a personal note, during my interrail trip last summer I talked to two American boys who were shift workers at Facebook. They told me that there are indeed nap rooms, however, nobody uses them. I hear you thinking, why, I have just read that this could potentially prevent Shift Work Sleep Disorder right? Well, when you decide to take a nap, you risk your opportunity to get promoted, since one of your colleagues who is not napping at the time is perceived to work harder. All in all, this preventative approach is interesting and worth exploring, however, something in the work culture needs to be changed as well in order to let it succeed.
Author: Joyce Burger
Image: Joyce Burger