Is it winter blues or something more?

Written by: Tayah Benaissa

The transition from fall to winter may not be everyone’s favourite. With it comes inconveniences such as bulkier clothes, colder temperatures, shorter days, and little light. Our mood is susceptible to the environment around us and occasionally we can find our mentality being reflected in the murky world we are surrounded by. However, for some individuals, this is a constant state of being during the winter season. For some, it may entail a serious onset of depression, known as seasonal affective disorder (SAD).


What is SAD?

SAD is a subtype of depression that starts at the same time and ends at the same time every year (Seasonal Affective Disorder, 2018). Winter SAD is the most common, where symptoms occur in the late fall or early winter, persist throughout the winter and go away during spring or summer. It is possible to have SAD onset when transitioning into the spring or summer months. This is known as summer SAD; however, this is a very rare occurrence. To be diagnosed with SAD according to the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders), you must have experienced a major depressive episode within the same season for at least 2 consecutive years (Rohan & Rough, 2017). There must also be a clear relationship between the onset and remission of symptoms and seasonal changes. The seasonal depressive episodes must outweigh the non-seasonal depressive episodes in the patient’s lifetime.


Signs and Symptoms

Summer SAD and winter SAD share common symptoms, but differ slightly in a few aspects (Seasonal Affective Disorder, 2018). As expected, both cause the typical symptoms of depression such as low energy, agitation, moodiness, feeling worthless, disturbed sleeping patterns, change in weight, and thoughts of death or suicide. Unique symptoms of Winter SAD include weight gain, oversleeping, and craving for foods high in carbohydrates. Summer SAD, contrastingly, can result in insomnia, lack of appetite and weight loss, and anxiety. Summer SAD symptoms result in a “melancholic presentation” (Rohan & Rough, 2017), whereas winter SAD symptoms are known to produce the “atypical presentation” (Rohan & Rough, 2017). If SAD is left untreated, it can lead to school/work trouble, social withdrawal, substance abuse, other mental illnesses (eating disorder, anxiety, etc.) and suicidal behaviour (Seasonal Affective Disorder, 2018).



A definitive cause is unknown; however, melatonin and serotonin levels are known factors, as well as the body’s circadian rhythm (Seasonal Affective Disorder, 2018). It is the combination of fluctuations in serotonin levels that create an abnormal circadian rhythm (Melrose, 2015). Serotonin is a chemical neurotransmitter that is naturally produced in the body and acts as a mood stabilizer (Scaccia, 2017). Melatonin is a hormone (a chemical signal that travels via blood) that is produced at night to induce sleepiness. The circadian rhythm is a 24-internal clock that makes up our sleep and wake cycles (What is Circadian Rhythm?, 2018). This rhythm is regulated by increases and decreases in melatonin levels. In turn, melatonin levels are dependent on the time of day and levels of light exposure in the environment.

Those who have SAD release their circadian signal at different times than others. This signal indicates a change in seasons and therefore a change in day duration (Melrose, 2015). In addition, they release a greater amount of melatonin and feel lethargic for a greater portion of the day. They also cannot normally regulate the levels of serotonin in the body, resulting in lowered serotonin activity, impacting their mood. This may be in part due to differences in their levels of serotonin transport proteins, such as SERT. The higher the level of SERT in the body, the lower the activity of serotonin. The purpose of SERT is to prevent the uptake of serotonin and promote its recycling (SLC6A4, 2018). SERT transports the serotonin molecules from the space in between communicating brain cells (also known as neurons) back to the brain cell that it came from (the presynaptic neuron). This function is needed to regulate its transport, but in SAD there is a dysregulation. Other physiological and genetic factors also come into play (Rohan & Rough 2017).



There are many different ways of treating SAD. The most common treatments include cognitive-behavioural therapy, anti-depressants, and light therapy (Seasonal Affective Disorder, 2017). Currently, there is only one FDA-approved drug that specifically treats SAD - bupropion XL (Rohan & Rough, 2017). However, the most common drugs to treat SAD are SSRIs (selective serotonin reuptake inhibitors), which allow the neurotransmitter serotonin to stay in the body longer and not get recycled as quickly, resulting in a greater mood stabilizing effect. Light therapy involves being exposed to bright light from a light box once a day. Typically, 10,000 lux2 (a measure of light intensity) of fluorescent light is given for 30 minutes a day. It is meant to simulate natural outdoor lighting conditions (Light therapy, 2017). The light must enter your eyes, but the patient shouldn’t look directly into the light box, to avoid damaging the eyes. It is thought to increase serotonin levels. Studies have found that it is most effective when administered in the morning (Rohan & Rough, 2017). Cognitive behavioural therapy is a form of “talk therapy” (also known as psychotherapy) that challenges negative thought patterns that guide our behaviour (Cognitive behavioral therapy, 2017). It aims to help a person perceive events and respond to them in a different way. This can be applied to those with SAD.


Author’s Note

As with any mental illness, communication with those close to you and your doctor is key in recovery. Know that you aren’t alone and remember to take care of yourself this season!



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