Seasonal Affective Disorder And Wellbutrin: An Overview

Have you considered clinical trials for Seasonal affective disorder (SAD)?

We make it easy for you to participate in a clinical trial for Seasonal affective disorder (SAD), and get access to the latest treatments not yet widely available - and be a part of finding a cure.

What is Seasonal Affective Disorder?

Seasonal affective disorder (SAD) is a subtype of major depressive disorder that occurs in a seasonal pattern, with symptoms appearing and disappearing during certain seasons each year. 

The most common form of SAD is winter pattern SAD, where symptoms begin to appear in the autumn and winter months and disappear in spring or summer. 

Some people may experience a rarer form called summer pattern SAD, where symptoms occur during the spring and summer and resolve in autumn or winter. 

Approximately 4 to 10%¹ of people experience SAD, with females and those aged between 18 to 30 more likely to experience the condition. 

SAD is also more common if you have a family history of mental illness, such as bipolar disorder, and live far from the equator.


Both SAD patterns share similar symptoms to major depression, but each pattern has its own set of typical symptoms. 

Common symptoms of winter pattern SAD include:

  • Sleeping more than usual

  • Daytime fatigue

  • Difficulty concentrating

  • Lack of interest in activities you previously enjoyed

  • Low mood 

  • Intense carbohydrate cravings

  • Weight gain

Common symptoms of winter pattern SAD include:

  • Irritability

  • Agitation

  • Trouble sleeping

  • Restlessness

  • Poor appetite

  • Weight loss

  • Low mood

Potential causes

The causes of SAD have not yet been determined, but there are several factors that may play a role. 

Neurotransmitter and melatonin levels

Research suggests that people with SAD have reduced neurotransmitter levels² in the brain, such as serotonin, or they may have difficulty regulating neurotransmitters. 

Serotonin helps regulate mood, so reduced or dysregulated levels could lead to symptoms of depression. 

Melatonin, a hormone produced in the pineal gland in the brain, may also play a role in SAD³. Melatonin levels rise in response to reduced evening light, letting the body know it's time to sleep. 

People with SAD may overproduce melatonin due to the shorter and darker winter days, causing them to feel tired and lethargic. 

This combination of increased melatonin and decreased neurotransmitter levels may cause disruptions to circadian rhythms in people with SAD. Circadian rhythms are the body's 24-hour "clock" that responds to daily and seasonal light patterns. 

People with SAD may have dysregulated circadian signals⁴, making it difficult for their bodies to adapt to seasonal changes.  

The link between vitamin D and depression

There are also associations between vitamin D levels and depression⁵. Vitamin D helps maintain healthy bones, cell growth, immune function, and it may help regulate serotonin production in the brain.

As the body produces vitamin D in response to sunlight exposure, reduced sunlight in winter could lead to decreased vitamin D levels, impacting serotonin production and contributing to symptoms of depression. 

What about summer pattern SAD?

There are fewer identified factors that may contribute to summer pattern SAD. For example, melatonin production may be disrupted by increased sunlight in summer, resulting in irritable moods and difficulty sleeping. Additionally, increased pollen⁶ in summer may also negatively impact mood. 

Various treatment options are available for SAD, including light therapy, psychotherapy, and antidepressant medications. 

If you think you may be suffering from SAD, it's important to talk to a healthcare professional about the condition and your options for managing it. 

What is Wellbutrin?

Wellbutrin is the brand name of an antidepressant medication called bupropion, an FDA-approved medication for treating major depressive disorder and SAD. 

Wellbutrin is different from more commonly known antidepressant medications like Prozac (fluoxetine) and Zoloft (sertraline). These medications are selective serotonin reuptake inhibitors (SSRIs), which prevent the reuptake of serotonin, increasing serotonin levels in the brain. 

Wellbutrin is a norepinephrine-dopamine reuptake inhibitor (NDRI), which prevents the reuptake of norepinephrine and dopamine, increasing their levels in the brain, which helps to regulate mood. 

How can you get Wellbutrin?

Your doctor can prescribe Wellbutrin for you. It is available in three different formulations, and the dosage varies depending on the formulation.

  • Immediate-release tablets (Wellbutrin) — These start working shortly after taking them to treat major depressive disorder, beginning with doses of 100mg twice a day up to a maximum of 150mg three times a day.

  • Sustained-release formulations (Wellbutrin SR) — Usually taken as one 150mg dose per day, which can be increased to a maximum of 200mg twice per day to treat major depressive disorder. 

  • Extended-release formulations (Wellbutrin XL) — Taken once per day, typically 150 mg but can be increased up to 450 mg, to treat major depressive disorder and prevent SAD.

What does the research show?

Bupropion XL is currently the only antidepressant medication licensed for the prevention of SAD. 

In three clinical trials, Wellbutrin XL was effective at preventing SAD⁷ in people who had previously experienced the condition by varying the dosage during different seasons.

A 2019 review⁸ of second-generation antidepressants for SAD treatment, including bupropion XL, found that it effectively prevented SAD in people with a history of the condition. 

However, the medication was found to cause a higher risk of insomnia, headaches, and nausea. In addition, in trials, bupropion XL has only been compared to a placebo medication and has not yet been compared to other antidepressant medications. 

As a result, it is unknown whether Wellbutrin/bupropion is more or less effective than other antidepressant medications for the treatment or prevention of SAD. 

Wellbutrin risks and side effects

If you are considering taking Wellbutrin to treat your SAD, it's important to know the risks of this medication. Make sure to discuss these risks with your healthcare provider to determine whether Wellbutrin is an appropriate treatment option for you.

The two most serious potential side effects are seizures and suicidal thoughts:

  • Suicidal thoughts — Wellbutrin may increase the risk of suicidal thoughts and behavior in young people up to age 24, so it’s crucial to keep track of any issues you experience, particularly when first taking it.

  • Seizures — While rare, Wellbutrin can increase seizure risk. Before taking Wellbutrin, inform your healthcare provider if you have ever had a seizure. 

Wellbutrin may also negatively interact with some medications, reducing its effectiveness or increasing the risk of side effects. These medications include:

  • Blood-thinning medications

  • Antipsychotic medications

  • Monoamine oxidase inhibitors (MAOIs)

  • Other antidepressant medications, such as Prozac and Zoloft

Be careful with how much alcohol you consume while taking Wellbutrin, as alcohol can increase the side effects of the medication, including seizures and suicidal thoughts. 

Wellbutrin can lead to less severe side effects, which typically go away within a few weeks of starting the medication. These include:

  • Gastrointestinal issues

  • Loss of appetite

  • Headaches

  • Insomnia

  • Increased sweating

  • Dizziness

  • Drowsiness

  • Restlessness

  • Nervousness

Some Wellbutrin side effects may be severe and potentially life-threatening, including:

  • Fainting

  • Aggressiveness

  • Chest pain

  • Trouble breathing

  • Irregular or rapid heartbeat

  • Dark-colored urine

  • Severe nausea or abdominal pain

  • Severe headaches

  • Seizures

  • Allergy symptoms such as hives, itching, breathing difficulties, or abnormal swelling

  • Yellowing skin and eyes

When should you seek medical help?

If you experience any of the above side effects while taking any form of Wellbutrin, seek immediate medical assistance. It's also important to consult your healthcare provider if you experience less severe side effects that become difficult to manage or don't subside after a few days.

Ensure you don’t suddenly stop taking the medication without seeking medical advice, as this may worsen your symptoms of depression.

Can I take Wellbutrin while pregnant?

Current data⁹ has not identified any risks of congenital disabilities when taking Wellbutrin while pregnant during the first trimester.

While there is some evidence for adverse effects on fetuses in animal studies, there is not enough data on whether these risks occur in humans.

The benefits of treating depression symptoms in pregnancy may outweigh the possible risks. Still, a doctor can help you assess whether taking antidepressants is safe and beneficial during pregnancy.

The lowdown

Seasonal affective disorder is characterized by recurrent depressive episodes that coincide with seasonal changes. Symptoms typically appear during a particular season and disappear when that season ends.

Wellbutrin is an antidepressant medication approved for treating SAD that helps to regulate neurotransmitter levels. Studies have shown that Wellbutrin is effective in preventing SAD.

As there are potential risks and side effects, ensure you speak to your healthcare provider about whether Wellbutrin treatment is right for you.

Have you considered clinical trials for Seasonal affective disorder (SAD)?

We make it easy for you to participate in a clinical trial for Seasonal affective disorder (SAD), and get access to the latest treatments not yet widely available - and be a part of finding a cure.

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