Do you suffer from Seasonal Affective Disorder? What can you do?
Humans are affected by different rhythms in our surroundings. We often hear about circadian rhythm related to the day/night cycle within 24 hours. This does impact Seasonal Affective Disorder, but one other type of rhythm has even more of an impact.
Circannual rhythms refer to biological cycles or patterns that occur annually, typically within a year-long timeframe. These rhythms are found in various living organisms, influencing physiological and behavioural changes in response to seasonal environmental variations.
In animals, circannual rhythms can regulate migration, reproduction, hibernation, and moulting. For instance, birds might migrate southward for the winter in response to changes in daylight hours and temperature. Some mammals, like bears, exhibit hibernation patterns triggered by seasonal changes, allowing them to conserve energy during periods of scarcity.
In humans, circannual rhythms are generally less pronounced compared to daily circadian rhythms, but they might still influence certain aspects of physiology and behaviour. Seasonal variations can impact mood, energy levels, sleep patterns, and even susceptibility to certain health conditions.
Seasonal Affective Disorder (SAD) is one example of how circannual rhythms might affect humans, with some individuals experiencing depressive symptoms during specific seasons, particularly fall and winter, when daylight decreases.
The body's response to changing seasons, variations in daylight, temperature, and other environmental cues can subtly influence these circannual rhythms. While not as overt or immediately noticeable as daily circadian rhythms, circannual rhythms still play a role in regulating certain biological processes and behaviours in many organisms, including humans.
What is seasonal affective disorder?
Seasonal Affective Disorder (SAD) is a type of depression that typically occurs at a certain time of year, usually in the fall and winter months when there is less natural sunlight. It's believed to be related to changes in light exposure and the body's internal clock.
Melatonin: This hormone is produced by the pineal gland in response to darkness. As the days get shorter (in the Northern Hemisphere in Fall/Winter/Spring), melatonin is longer. Our physiology is impacted by the location we are on the Earth to the Sun. There are neural and hormonal changes as a result. The brain remembers what it was like yesterday (in terms of melotonin and light exposure), so as we move from winter into spring, this can be even more challenging.
Symptoms of SAD
Symptoms of SAD can include feelings of sadness, hopelessness, low energy, irritability, changes in appetite or weight, difficulty concentrating, and a lack of interest in usual activities. People with SAD may also experience oversleeping, social withdrawal, and a general feeling of heaviness in their limbs.
Practices to Support
We often recommend getting out into sunlight within 90 min of waking, but that can be a challenge when you wake up to darkness (Northern Hemisphere).
One practice, as mentioned by Dr. Andrew Huberman, is light therapy done in the early morning after waking. As fall transitions to winter, use a light source (900 lux) for 2-3 min in the early morning and gradually increase the time over the winter. This can “trick” the brain and its relationship to melatonin.
I use one all winter during my morning meditation. I purchased a simple one off of Amazon ($35) that works effectively. You can also put it on your desk or anywhere that makes sense for you to use early morning.
