Seasonal Affective Disorder can kick in with changes in our circadian rhythm as the number of sunlight hours drop and we have more hours of darkness. Our melatonin production may increase during the Fall and Winter due to increased hours of darkness contributing to lower energy and feeling tired more and having a hard time waking up in the morning.
The best way to combat SAD and improve your mood and motivation throughout the Fall and Winter is exposing yourself to as much bright light during the day. Wake up in the morning and use a bright light that mimics outdoor light (sunrise alarms) and open your curtains to let in any natural daylight as soon as you get out of bed – this helps to provoke a secretion in cortisol in the morning which inhibits melatonin production.
Recent research has shown a link between light and higher active serotonin levels which demonstrates that SAD can also be associated with fluctuating serotonin levels (2). Lower serotonin can lower our mood since it is a neurotransmitter responsible for regulating our calm and positive or happy mood.
Our neurons have a serotonin transporter protein (SERT) which enables serotonin to be taken back in the neurons for storage and cleared out from the active space when it is not needed (2). Light lowers this SERT activity which keeps more serotonin active – why sunlight in the summer can make us feel happier. In the winter, a study showed that some people tend to have higher SERT activity because of the low levels of light leading to more serotonin clearance and these individuals displayed signs of SAD. (2) This is another reason why exposing yourself to as much light as possible can help to increase serotonin levels.
Increased levels of serotonin can yield what we call serotonin syndrome but this is more common when one is supplementing with nutrients to boost serotonin along with taking antidepressants and highlights why it is SO important to work with a healthcare professional to ensure there are no interactions between your supplements and medications.
