Circadian rhythm imbalances are at the root of Seasonal Affective Disorder (S.A.D.), a number of sleep disorders, jet lag, some cases of Attention Deficit /Hyperactivity Disorder and Shift Work Disorder. (For more on how to address S.A.D, see my blog post entitled ‘How to keep the Winter Blues at Bay‘. ) It is estimated that approximately 22 million Americans classify as shift workers. Shift workers, (which includes those who work nights, early mornings and swing shifts), are more likely to have impaired work performance and increased work absences than those working day shifts. Night/rotating shift workers are 2-4 times more likely than daytime workers to fall asleep while driving.
Not all shift workers will suffer from Shift Work Disorder (SWD), but it is critical that early detection and treatment be employed for those suffering from SWD. Shift Work Disorder (SWD) is a condition that is associated with chronic partial sleep loss and misalignment of the circadian rhythm. SWD is characterized by insomnia, daytime sleepiness and decreased quality and duration of sleep. Sleep is critical to proper detoxification, neuroendocrine function (neurological and hormonal regulation) and blood glucose regulation. Thus chronic partial sleep loss can lead to a number of adverse effects: increased risk of mood disorders (depression and bipolar), anxiety disorders, substance dependence, hypertension (high blood pressure), ulcers, heart disease, obesity, diabetes cancer, musculoskeletal pain, gastrointestinal complaints and decreased fertility. Memory consolidation, alertness and learning capacity are decreased. Those suffering from SWD also miss more family and social events as their different sleep schedule tends to interfere with these events and can disrupt relationships.
Genetics and chronotype play a role in determining whether an individual subjected to shift work will suffer from Shift Work Disorder. Those with a predisposition to insomnia generally do not adapt well to shift work and are at an increased risk of developing SWD. Morning types are more likely to suffer from SWD than evening types. Further, chronotypes can be useful in determining what shift work one is more suited to. Evening types will adapt better to evening and night shifts, whereas morning types will generally adapt better to working early morning shifts. To determine one’s chronotype, the Morningness-Eveningness Questionnaire (MEQ) is very helpful. Click here for an auto-scored version.
As those suffering from shift work disorder are at an increased risk of mental illness, substance dependence, sleep disorders and physical illness, proper diagnosis and treatment of SWD is imperative. Treatment includes chronotherapeutic interventions, sleep hygiene education and the select use of sedative medications (naturopathic/pharmaceutical as appropriate).
Chronotherapeutic interventions include the use of short naps, amber glasses, regularity of sleep-wake cycle, low-dose melatonin and light therapy. Short naps (taken prior to or during a night shift) can increase alertness, improve reaction time and decrease accidents. Amber glasses, worn when working nights and/or on the drive home, can minimize the adverse effects of bright light exposure during the night. Low-dose melatonin can help one adapt to a new sleep-wake cycle – cuing the body that it is night- whether in rotating shift work, a new shift schedule, or when suffering from a skewed sleep-wake cycle (consistently waking too early or not being able to get to sleep at ‘night’. Light treatment can be used to help sync the circadian rhythm as well (advancing it if light is administered after waking & delaying it if light treatment is administered prior to bed).
To improve sleep quality, be sure to have a dark bedroom (use curtains or blinds that block out all light) and keep loud noises to a minimum (also consider wearing ear plugs and/or using a white noise machine). Avoid caffeine, alcohol, smoking and large meals before bed. See this prior blog post to learn more about sleep hygiene tips and other helpful information on sleep. Deserving of a whole blog post of its own, sleep apnea is a very prevalent sleep disorder that is important to rule out as a cause of insomnia. Sleep studies are important in accurately diagnosing sleep apnea.
Some final tips: for those working rotating shifts, shifts that rotate counterclockwise are easier for the body to adapt to than clockwise-rotating shifts. To ensure better sleep-wake cycles and improved sleep quality, it is important to maintain the same sleep and wake times throughout the week (even on days off) and to follow good sleep hygiene tips (not eating right before bed, limiting caffeine prior to sleeping and keeping stimulation to a minimum prior to bed). Shift work can be a challenge for many to maintain, but I hope that this helps you or someone you care about better sustain aberrant work schedules and to enjoy greater health as a result!
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Doghramji, K., Lenz, T.L. & Markov, D. (2011). Advances in the Management of Shift-Work Disorder. US Pharmacist, Dec., 1-32.
Wirz-Justice, A., Benedetti, F. & Terman, M. (2009). Chronotherapeutics for Affective Disorders. Basel: Karger.