Medical Review by Jennie Stanford, MD, FAAFP, DABOM
Summary
- Seasonal affective disorder is a type of depression that occurs in fall or winter. Symptoms include sadness, fatigue, oversleeping, craving carbohydrates, social withdrawal, and difficulty concentrating.
- SAD is believed to be caused by reduced sunlight exposure, which disrupts your circadian rhythm and causes imbalances in serotonin and melatonin. Genetics and geographic location also play a role.
- Selective serotonin reuptake inhibitors are often the first choice for treating SAD, while bupropion is the only medication specifically FDA-approved to prevent it.
- Light therapy, cognitive-behavioral therapy (CBT), and lifestyle changes may also help manage SAD. Strategies include regular exercise, a consistent sleep routine, and increasing natural light exposure.
Understanding the signs of seasonal affective disorder & finding the help you need
Seasonal affective disorder (SAD) is a type of depression that follows a seasonal pattern, usually starting in the fall or winter when there is less daylight and easing up by spring or early summer. During these darker months, you might notice a dip in your mood, feel more tired, or struggle to think clearly.
SAD isn’t just about feeling down during winter—it’s a real mental health condition. It can happen on its own or as part of bipolar disorder. If you notice a pattern of feeling low during the same months each year, it could be a sign of SAD.
Fortunately, there are ways to manage seasonal affective disorder. In this article, we’ll explore its causes, symptoms, and treatment options. This can help you make informed decisions about your mental health and seek expert guidance from a healthcare professional.
What causes seasonal affective disorder?
Seasonal affective disorder happens when seasonal changes throw off your body’s natural balance. Although the exact causes of SAD are still being studied, reduced sunlight, disrupted circadian rhythms, changes in brain chemicals, reduced sensitivity to light, and genetics can all play a part.
Sunlight
Sunlight is key to keeping your body’s 24-hour sleep-wake cycle—your circadian rhythm—on track. When there’s less sunlight during fall and winter, your brain can produce too much melatonin (the sleep hormone) and not enough serotonin (the mood-boosting brain chemical). This chemical imbalance can leave you feeling tired, sad, and sluggish.
Light exposure
Light exposure also plays a big role in your mood. Special cells in your eyes respond to blue light, which helps regulate sleep, concentration, and alertness. But if you have SAD, these cells may not react as effectively to light—especially during winter—making it tougher for your brain to adjust to seasonal changes.
Genetics
Genetics might also raise your risk. If depression runs in your family, you could be more likely to experience SAD. In fact, around 15% of people with SAD have a close relative, like a parent or sibling, who also struggles with it.
Environment
Where you live in the world matters too. SAD is more common in places farther from the equator, where winter days are shorter and darker.
Symptoms of seasonal affective disorder
Seasonal affective disorder has various symptoms that range from mild to severe, impacting your daily life. These symptoms include several common signs of depression, along with more specific ones related to SAD itself.
Specific symptoms of SAD
- Oversleeping
- Overeating (particularly cravings for carbohydrates)
- Social withdrawal
General symptoms of depression
- A persistent sad or anxious mood
- Feelings of hopelessness
- Irritability that makes it difficult to cope with everyday situations
- Feelings of guilt or worthlessness
- A loss of interest in activities you once enjoyed
- Fatigue or a general lack of energy
- Difficulty with concentration, memory & decision-making
- Thoughts of death or suicide
Diagnosing seasonal affective disorder
Like any mood disorder, getting an accurate diagnosis is the first step towards effective treatment. Your healthcare provider will help you understand your symptoms by looking at important factors like:
- How long your symptoms have been present
- How often they occur
- How long they last
- How they affect your daily life
For seasonal affective disorder (SAD), having a thorough patient history and mental status examination is especially important. Your healthcare provider will conduct a detailed evaluation using established diagnostic criteria.
According to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), the criteria for depression with a seasonal pattern include experiencing depression that begins and ends during a specific season each year, with full remission during other seasons, lasting for at least two years.
Since SAD is linked to major depressive disorder or bipolar disorder, your provider will also look for signs of these conditions and see how your symptoms change with the seasons. They may use tools like the Seasonal Pattern Assessment Questionnaire (SPAQ) to gather information about your symptoms.
SAD can often co-occur with other mental health issues, such as alcohol abuse, anxiety disorders, and personality disorders. Providing honest information about these factors during your evaluation is crucial, as they can complicate your diagnosis and treatment.
Treatment approaches
Light therapy
Light therapy involves using a light box that gives off a bright white light, similar to natural sunlight. For your brain, this artificial light works just like the real thing. To get the best results, make sure your lightbox provides 10,000 lux of exposure. (Lux is a measure of how intense the light is—a sunny day can reach 50,000 lux or more).
When using the lightbox:
- Don’t stare directly at the light. Keep your eyes open, but look just past it.
- Place the box about a foot away in front of you or slightly to the side.
- Spend around 30 minutes in front of the light each morning, ideally before 10 a.m.
You’ll usually start feeling better after 2 to 3 weeks, but it’s best to continue light therapy until your symptoms naturally improve in the spring or summer.
Light therapy is generally safe, with only minor side effects like headaches or eye strain. However, if you have any eye conditions, it’s a good idea to check with an eye doctor before starting.
Medication
Selective serotonin reuptake inhibitors (SSRIs), like Lexapro, Zoloft, or Prozac, are often the first choice for treating seasonal affective disorder (SAD). You can use them on their own or along with light therapy for better results.
Bupropion is the only medication specifically FDA-approved to prevent SAD. Research shows that starting bupropion between September and November, before symptoms usually appear, can help lower the risk of depressive episodes during winter.
How quickly medications work depends on factors like the type, dosage, and your overall health. Some people may start to feel better within the first week, while others may need up to 6 weeks to feel the full benefits.
Cognitive behavioral therapy
Cognitive-behavioral therapy (CBT) can help you identify and change negative thought patterns, which has been shown to be effective in reducing depression symptoms.
For individuals with seasonal affective disorder, CBT-SAD is a tailored approach that targets the unique challenges of seasonal depression. This version of CBT focuses on identifying negative thoughts related to the changing seasons and replacing them with more positive ones.
CBT-SAD also encourages behavioral activation techniques—the process of deliberately practicing certain behaviors to positively change the way you feel. This can help you stay active and engaged during especially difficult months.
Lifestyle modifications and home remedies
Having a good sleep routine and staying active may help improve symptoms of seasonal affective disorder. These strategies are safe and offer additional health benefits:
- Avoid screen time before bed
- Stick to a regular sleep-wake schedule
- Spend time outdoors or adjust your workspace to increase natural light exposure
- Do exercises like walking, running, or cycling to boost your mood
While some supplements, such as vitamin D, melatonin, and St. John’s wort, may offer limited benefits, but this is based on small studies that produced limited evidence.
These lifestyle changes and supplements might complement other treatments, but it’s always a good idea to check with your healthcare provider before starting any new therapies.
Get your mental health back on track with Lemonaid Health
If you or someone you know may be showing signs or symptoms of seasonal affective disorder, reach out to a healthcare provider for help as soon as possible. Working with a qualified medical professional is the best way to develop a treatment plan that is safe and effective for you.
Our team at Lemonaid Health can help. Find support for SAD with a qualified US-based health professional who can help you understand your symptoms and find appropriate solutions—including FDA-approved medication in clinically indicated cases.
