A person with a lifestyle of getting up early in the morning and going to bed early in the evening is called a morning person. The book Mystery of Morning Person written by Hiroshi Saisho in 2001 was sensational in Japan and South Korea [1]. Saisho insisted that a morning person is more energetic, creative, and socially successful. At the time, exploring the genetic factors that determine chronotype, I thought it was wrong to force a person to be morning-oriented because chronotype is genetically determined. But this idea had changed. Chronotype has innate genetic factors but can be sufficiently altered by the environment and individual’s efforts. And I believe that the lifestyle of morning types is healthy, so I recommend patients to be morning-oriented.
This change in my idea is attributed to the research I have conducted that tracks the shifting of the circadian rhythm of patients with mood disorders. In the study with 31 bipolar disorder patients, my team analyzed the circadian rhythm of clock gene expression and levels of cortisol in depression patients and found that the circadian rhythm was about five hours and more than 12 hours delayed in manic patients. In both cases, normal circadian rhythm was restored when they recovered from depression and mania after treatment [2,3].
It is relatively well known that insomnia, depression, and bipolar disorder all occur more frequently in evening people [3,4]. This may be related to the easy delay of circadian rhythms. Then what are the ways to prevent this? It is to be a morning person. Even if you are an evening person, if you wake up early in the morning and see enough bright light and engage in physical activities, your circadian rhythm can be advanced and become a morning person.
Recently, as a book titled The Miracle Morning by Hal Elrod became popular worldwide [5], many people are trying to be morning-oriented. Messages of The Miracle Morning are same as the takeaways of Saisho’s book. They argue that waking up earlier than others can make an energetic and successful life. What makes Elrod different from Saisho was that he presented a more specific way to become a morning person by creating something called a morning routine.
Very recently, research showing the advantages of living a morning-oriented life has been published in JAMA Psychiatry. After collecting data from 85,000 individuals wearing activity trackers for seven days and 250,000 who filled out sleep questionnaires, Daghlas et al. [6] found that those who went to sleep an hour earlier and got up sooner than usual showed a reduced risk of depression by 23 percent. Also, adjusting the waking time to two hours earlier reduced the risk of depression by 40 percent. Although there are still debates, the advantage of morning chronotype seems to be increasingly established, at least in terms of mental health.
In Mystery of Morning Person and in The Miracle Morning, Hiroshi and Elrod strongly recommended waking up early in the morning. However, “how” to become a morning person was overlooked: it is to see a bright light in the morning. Of course, if you are active early in the morning, you are naturally exposed to light. Understanding the importance of light in controlling circadian clocks in our bodies and utilizing such insight will make it easier to become a morning person. That is, if you see enough light immediately after you wake up, your circadian rhythm is pulled forward and you naturally become a morning person who goes to bed early and wakes up early. In addition to studying circadian rhythms in many ways, it is also the role of researchers in chronobiology to inform the public of how to manage circadian rhythms for health.