Psychological stresses influence on skin appearance and health

Skin appearance potentially has a profound effect on self-confidence. Many skin diseases may not have a serious effect on general health but can significantly impact patients' lives. Mood and mental status can also manifest in the form of body-related symptoms like the appearance of the skin. Some factors—including diet, skin microbiome, environmental pollution, and infections—affect skin freshness and health. However, it seems that mental states have a greater impact on skin. People who have had a bad day and are under stress often experience dull and tired-looking skin. Therefore, physicians consider skin check-ups for such conditions.

As they do with most diseases affecting the body, physicians and specifically dermatologists traditionally prescribe medication for the treatment of skin-related conditions. But there is a significant amount of evidence indicating a strong connection between mental illnesses and skin health. On the other hand, skin diseases are closely linked to mental disorders. The prevalence of mental disorders among patients with skin disorders is higher than that of other physical diseases such as cardiovascular diseases.

Sleep disorders may affect skin health, and vice versa

In atopic dermatitis (AD), which is accompanied by severe itching, patients may also experience sleep disturbances and other mental distress. It's not just the discomfort of itching that interferes with sleep but that inflammatory molecules related to the lesions circulate systemically, cross the blood-brain barrier, and create sleep disturbance via brain mechanisms. The reverse is also true: Sleep disorders can worsen AD by disrupting the immune system and increasing oxidative stress [1].

When we cannot sleep enough or experience poor sleep quality, it is considered a sleep disorder. Sleep disorders, such as insomnia, sleep apnea, and Willis-Ekbom disease (also known as restless leg syndrome), can have a significant impact on both physical and mental health. Sleep loss causes anxiety, depression, distress, and other mood problems. It has been shown that sleeping fewer than than five hours is associated with increased all-cause mortality and, particularly, cardiovascular morbidity. As with most chronic disorders, the etiology of sleep disorders involves thethe interaction of genes and environmental factors [2].

Insomnia and other types of sleep disorder are highly prevalent among the general population. The Covid-19 pandemic worsened sleep problems for any. According to the Sleep Foundation, 52 percent of individuals with Covid-19 experience a type of insomnia known as "covidsomnia." [3]

Insomnia can be caused by several behavioral habits, such as irregular work schedules and staying up late at night. One of the most common causes of chronic insomnia at present is the blue light emitted from the screens of electronic devices such as laptops, TVs, and smartphones. Blue light disrupts the normal day/night, or circadian, rhythm of the body. The circadian rhythm regulates many biological processes such as the sleep/wake cycle, appetite, hormonal release, metabolism, immune response, and more.

The role of melatonin in skin health

The suprachiasmatic nuclei (SCN) in the hypothalamus serve as the central regulator for the circadian rhythm. They respond to light/dark information from melanopsin-expressing retinal ganglion cells and melatonin hormone from the pineal gland. As day turns into night, the human body normally releases melatonin, while the light of day normally inhibits its secretion. The main function of melatonin is to regulate the sleep/wake cycle. However, receptors for the hormone are distributed in many other organs, indicating that melatonin has multiple functions in the body. The actions of melatonin are mediated by receptors that are located on the cell membrane or inside target cells.

In aging and certain diseases, melatonin production decreases, which leads to circadian disruption. Low levels of melatonin at night may result in poor sleep quality, which is associated with many serious health problems, including cardiovascular disease, obesity, diabetes, and mental disorders. One of the target tissues of melatonin action is the skin. Melatonin receptors are expressed in skin cells, and melatonin is also synthesized in the skin, in addition to being a hormone released by the pineal gland.

Melatonin acts as a potent antioxidant in the skin and prevents oxidative stress induced by the sun's ultraviolet radiation. Melatonin has powerful anti-inflammatory properties, helps maintain the integrity of mitochondrial function, and prevents mitochondrial damage during aging. Melatonin also influences collagen production in dermal fibroblasts, and a decrease in melatonin levels in older individuals worsens the aging process.

By restoring circadian rhythmicity, melatonin supplementation can repair skin damage caused by sleep disruption. Melatonin also affects epigenetic mechanisms, which lead to the inhibition of some age-related genes and the activation of genes associated with skin health. Therefore, melatonin supplementation can be a promising strategy for preventing age-related skin disorders or disruptions of the circadian cycle induced by environmental factors [5].

Many factors related to lifestyle, such as excessive use of smartphones or tablets at night and aging, can disrupt the circadian cycle and cause sleep disorders. Recent studies suggest that melatonin supplementation may improve skin disorders associated with age and the environment.