News — The annual pattern of winter depression and melancholy – better known as – suggests a strong link between your mood and the amount of light you get during the day.

To put it simply: The less light exposure one has, the more one’s mood may decline.

Wintertime blues are common, but about 10 million Americans are affected every year by a longer lasting depression called . Along with low mood, symptoms include anxious feelings, low self-esteem, longer sleep duration, constant craving for carbohydrates and low physical activity levels.

, and my research focuses on the effects of diet and lifestyle factors on functions such as mental distress, resilience and motivation.

Through my research, I have learned that seasonal affective disorder can strike anyone. However, people with a . In particular, young adults and women of all ages .

Why seasonal depression happens

When daylight saving time ends each fall, the one-hour shift backward reduces the amount of light exposure most people receive in a 24-hour cycle. As the days get shorter, people can experience general moodiness or a longer-term depression that is tied to a shorter exposure to daylight.

This happens due to a misalignment between the sleep-wake cycle, eating schedules and other daily tasks. Research shows that this mismatch may be associated , such as anxiety and depression.

Our sleep-wake cycle is controlled by the , an internal clock regulated by light and darkness. Like a regular clock, it and controls metabolism, growth and hormone release.

When our brain receives signals of limited daylight, it – even though we still have hours left before the typical bedtime. This can then affect how much energy we have, and when and how much we eat. It can also alter the brain’s ability to adapt to changes in environment. This process, called , involves the growth and organization of neural networks. This is crucial for brain repair, maintenance and overall function.

It is possible to to better align with the new light and dark schedule. This means getting daylight exposure as soon as possible upon waking up, as well as maintaining sleep, exercise and eating routines that are more in sync with your routine prior to the time change. Eventually, people can gradually transition into the new schedule.

The intimate connection between serotonin and melatonin

Serotonin is a chemical messenger in the brain that is a key player in regulating several functions such as . Serotonin also converts to melatonin with lower light intensity. As mentioned above, melatonin is a hormone that regulates the sleep-wake cycle and signals the brain that it’s time to sleep.

Less daylight exposure during winter months leads to the conversion of serotonin into melatonin , since it gets dark earlier. As a result, this untimely melatonin release causes a disruption in the sleep-wake cycle. For some people this can cause moodiness, daytime sleepiness and loss of appetite regulation, typically leading to unhealthy snacking. People with seasonal affective disorder often , because there is an intimate connection between .

Strategies to combat the winter blues

In winter, most people leave work when it’s turning dark. For this reason, for those who experience seasonal affective disorder, or even shorter periods of seasonal funk.

This can be as simple as getting some light shortly after awakening. Try to get at least one hour of natural light during the early morning hours, preferably about when the circadian clock is most sensitive to light. This is true no matter what your wake-up time is, as long as it’s morning. For people living at northern latitudes where there’s very little sun in winter, light therapy boxes – – can be effective.

You can also improve your sleep quality by avoiding stimulants like coffee, tea or heavy meals close to bedtime. – it increases serotonin production and supports circadian regulation. A balanced diet of complex carbs and healthy proteins , and practicing downtime before bed can reduce stress.

Taking these small steps may help the circadian rhythm adjust faster. For the millions with mood disorders, that could mean happier times during what are literally the darkest days.