By: Adam Perrault

Introduction
Seasonal Affective Disorder (SAD) is a common type of depression/mood disorder that recurs in the winter, with a recovery in the following spring or summer (Felix Torres,2024). The most common reason is that exposure to sunlight decreases. There are two types of SAD known as the winter pattern and summer pattern (Felix Torres,2024).
Signs Symptoms
SAD is a form of depression that is characterized by a seasonal pattern, with symptoms persisting for around 4 to 5 months each year (NIH, 2023). The signs and symptoms of SAD feature typical depression-related symptoms, which vary between winter-pattern and summer-pattern SAD (NIH, 2023).
Most symptoms are similar to depression such as feelings of being sad, worthless, guilt, and/or hopelessness, loss of pleasure or interest in activities/hobbies, difficulty remembering, concentrating, or making decisions, decreased fatigue, feeling slowed down, and loss of energy (NIH, 2023).
For the winter pattern of SAD, some different symptoms may include social withdrawal (isolate oneself from others), oversleeping, and overeating (can lead to weight gain) (NIH, 2023).
For the summer pattern of SAD the symptoms differ with symptoms like trouble sleeping, anxiety, poor appetite (can lead to weight loss), aggressive or violent behavior, and restless/agitation (NIH, 2023).
Causes
There is no specific reason discovered why people can get SAD, but some factors that come into play are cardiac rhythm (your biological clock), melatonin levels, and serotonin levels (Mayo Clinic, 2021). The decrease in sunlight during the fall/winter time can interrupt your body’s internal clock which can lead to feelings of depression and is a cause for Winter-pattern SAD (Mayo Clinic, 2021). Melatonin is a sleep-related hormone that can change from sunlight so less sunlight can change your mood and sleep patterns (Mayo Clinic,2021). Serotonin is a brain chemical that affects your mood and plays a role in SAD (Mayo Clinic,2021). Reduced sunlight can drop your serotonin levels which may lead to depression (Mayo Clinic,2021).
Relation to Epilepsy
Individuals with epilepsy are five to seven times as likely to experience SAD (Kanner, 2016). There isn’t a direct cause and effect between epilepsy and SAD, but rather a pathogenic mechanism, where the existence of one condition may contribute to the onset of the other. (Kanner, 2016). Shared mechanisms between depression and epilepsy refer to common underlying factors such as irregular CNS activity in multiple neurotransmitters, particularly norepinephrine, serotonin (5-HT), GABA, dopamine, and glutamate (Kanner, 2016).
Diagnosis and Treatment
There are multiple ways of treating SAD and ways to help relieve the symptoms. Treatments for SAD include psychotherapy, light therapy, and antidepressants (NIH, 2023). Psychotherapy is known to be called counseling or talk therapy and is helpful because it can teach new ways of “thinking and behaving and changing habits that contribute to depression” (NIH, 2023). Light therapy has been around since the 1980s to compensate for the reduced natural sunlight during the darker months. It involves sitting in front of a bright light box that’s around 20x brighter than normal outdoor light for 30-45 minutes every day (NIH 2023). Antidepressant medication can be used in a combination alone or along with talk therapy. How it works is that it changes certain chemicals in your brain involved in stress or mood (NIH, 2023). When starting antidepressants, they can take on average around 4-8 weeks before they take effect. Before taking full effect, problems regarding appetite, concentration, and sleep can take place (NIH 2023).
Other ways to ease the symptoms of SAD are exercising regularly, talking to others about how you feel, and doing things that make you feel better like going on a bike ride, gardening, eating healthy, or doing something nice for others (John Hopkins Medicine, n.d.).
Conclusion
Seasonal Affective Disorder (SAD) is a type of mood disorder/depression that is common and more common in people with epilepsy. There are many different symptoms one can experience and there are different treatment options available to help alleviate symptoms.
References
Johns Hopkins Medicine. (n.d). Seasonal affective disorder. Johns Hopkins Medicine. https://www.hopkinsmedicine.org/health/conditions-and-diseases/seasonal-affective-disorder
Kanner A. M. (2006). Depression and epilepsy: a new perspective on two closely related disorders. Epilepsy Currents, 6(5), 141–146. https://doi.org/10.1111/j.1535-7511.2006.00125.x
Mayo Clinic. (2021). Seasonal affective disorder diagnosis & treatment. Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/seasonal-affective-disorder/diagnosis-treatment/ drc-20364722
National Institute of Mental Health. (2023). Seasonal affective disorder. National Institute of Mental Health. https://www.nimh.nih.gov/health/publications/seasonal-affective-disorder Torres, F. (2024). Seasonal affective disorder. American Psychiatric Association. https://www.psychiatry.org/patients-families/seasonal-affective-disorder