The autumn blues that Donguibogam described centuries ago is actually addressed as a recognized condition in modern medicine. It is called 'seasonal affective disorder' or seasonal depression, and it tends to worsen particularly during autumn and winter. This goes beyond a simple emotional state and is deeply tied to neurotransmitters in our brain.
When sunlight exposure decreases sharply in autumn, several key changes occur in our brain. First, the secretion of serotonin, known as the happiness hormone, decreases. Sunlight is essential for serotonin synthesis, so as daylight shortens, serotonin levels naturally drop, leading to low mood and feelings of lethargy. Second, the secretion pattern of melatonin, the hormone that induces sleep, becomes disrupted. Melatonin is secreted when it gets dark. When sunlight hours decrease, the onset of melatonin secretion starts earlier or its volume increases excessively, causing daytime drowsiness and fatigue. As a result, our biological rhythm, or circadian rhythm, breaks down, which can impair sleep quality and degrade overall physical condition.
Furthermore, a lack of sunlight easily leads to vitamin D deficiency, and vitamin D plays a crucial role not only in bone health but also in brain function and immunity. Studies continually show that low vitamin D levels can increase feelings of depression and fatigue. Lastly, its connection to the stress hormone cortisol cannot be overlooked. Changes in sunlight exposure and the resulting disruption of bodily rhythms act as stress on the body, stimulating the hypothalamic-pituitary-adrenal axis and potentially increasing cortisol secretion. A chronic increase in cortisol negatively affects emotional regulation and can deepen anxiety and depression.
In this way, the movements and qi of heaven and earth and the grief of the lung in Donguibogam describe natural phenomena that, from the perspective of modern medicine, result from the complex interplay of reduced daylight from seasonal shifts, neurotransmitter imbalances, circadian rhythm disruptions, and hormonal changes. The signals sent by our bodies are too clear to simply brush off as the autumn blues. This is a time to pay close attention to your emotional state and seek help if needed.
