How Evening Habits Can Delay Sleep by Over 1.5 Hours, Warns Psychiatrist Marine Colombel
Psychiatrist Marine Colombel discusses how evening habits, particularly exposure to blue light, can significantly delay sleep onset by over 1.5 hours.
In the latest installment of our summer series on chronobiology, psychiatrist Marine Colombel sheds light on the optimal timing for sleep based on individual chronotypes.
Did you know that your tendency to be an early or late sleeper is influenced by your biological clock? Adhering to our biological cycles helps us feel energized and recuperate from daily fatigue. Whether you sleep little or a lot, your sleep needs are governed by a small area in the brain known as the suprachiasmatic nucleus. This nucleus regulates various hormonal cycles, including those related to sleep. A key player in this process is the hormone melatonin.
Aligning Sleep with Your Internal Clock
Melatonin is a hormone that follows a circadian rhythm, with its secretion typically peaking at specific times throughout the day. Production ramps up in the evening, signaling the body that it’s time to sleep. It reaches its highest levels between two to four hours before waking, at which point it begins to decline.
To effectively synchronize your sleep needs with your internal clock, it’s crucial to pay attention to sunlight exposure. While you are in the light, melatonin production is suppressed. Conversely, dim evening environments signal the internal clock to release melatonin, promoting sleepiness.
Tips for Better Sleep
If you find yourself feeling tired and wanting to sleep earlier, Colombel advises creating a dim atmosphere in your home as soon as possible. It’s best to avoid being outdoors too late, especially during the summer months. Additionally, steer clear of sources of blue light, which mimic sunlight and can disrupt your sleep cycle.
Blue light is emitted by LED screens, such as those on smartphones, and activates the retina's photoreceptors significantly more than white light from a lamp—up to 70 times more. This blue light can delay sleep onset by over 1.5 hours, resulting in the loss of an entire sleep cycle. Therefore, it’s advisable to turn off screens at least one hour before bedtime.
About Marine Colombel
Marine Colombel is a psychiatrist, university lecturer, and author specializing in the psychotherapeutic management of burnout, stress, and psychological trauma. She also teaches mindfulness at the University of Toulouse 3. Each month, she offers insights into psychological mechanisms and shares preventive advice for readers of Psychologies.
