How Can Sleep Patterns Influence Your Mood?
It’s no surprise that after pulling an all-nighter, we tend to be more quick-tempered, irritable, and stressed out. However, these “symptoms” tend to go away after a long needed rest. Our sleep-wake cycle is determined by our circadian rhythm, otherwise known as our body’s internal clock. Similar to other clocks, our biological clock resets everyday, and cycles between sleepiness and alertness at regular intervals. The circadian rhythm also “controls memory consolidation, the timing of hormone secretion, and body healing” (Epstein and Hassan). Typically, the circadian sleep phase occurs at night and is adjusted by light exposure in the morning. Hence, most people tend to sleep at night and wake up during the day. However, there is a range of times when the sleep phase can occur. Morning birds are programmed to sleep from early evening to early morning while night owls stay up late and sleep much later. But how can this sleep cycle impact our mood?
Research studies have determined that significant disruptions in circadian rhythms are found in people with bipolar disorder, anxiety, and depression. Our circadian rhythms not only impact our sleep/wake activity, but can also influence our body temperature, and hormonal cycles. Difficulty sleeping is sometimes one of the first symptoms of depression. Around 15-20% of people who have insomnia will develop major depression. It is also suggested that night owls have a greater predisposition to psychological disturbances. One study found that night-shift workers are 40% more likely to develop depression than their daytime counterparts. For the case of seasonal affective disorder, people feel more depressed during winter months. One possible explanation for this is the fact that our circadian cycle is disrupted as a result of the seasonal changes in daylight. Conversely, one of the many successful treatments of depression include bright light therapy, wake therapy, and interpersonal and social rhythm therapy; all of which directly impact our circadian rhythms (Epstein). Hence, in the case of people with seasonal affective disorder, one can try to use artificial light in the morning to realign their sleep-wake cycle.
While it is quite difficult to change our “circadian type” as it is genetically determined, we have all probably altered our circadian rhythm before without trying. This includes traveling to another time zone, working a new job with different work hours, or even adjusting to daylight savings time. After the initial jetlag, crankiness, and confusion, our body will sync in with the new time. Typically our circadian rhythm responds well to light cues, but even exercising, and the time of day we eat can change our body’s internal clock and adjust to the new conditions better. Our circadian sleep phase also tends to shift later during adolescence, but shifts earlier as we age further past adulthood.
Thus, it is the best if we all get a full night’s sleep to improve our general health. Most adults need between seven to nine hours of sleep to function at their best. Typically, it is best to wake up at around the same time every morning as it helps align our circadian rhythms. Developing a relaxing bedtime routine, turning off bright lights, and avoiding screen time for an hour before bed, can improve our sleep quality. Like diet and exercise, sleep is important, but it is also important to adjust in small increments and according to your own level of comfort.
References:
https://www.health.harvard.edu/blog/why-your-sleep-and-wake-cycles-affect-your-mood-2020051319792
https://ibpf.org/articles/circadian-rhythms-and-mood-control/
