Depression is a condition that causes a person to feel sad or miserable most of the time. It is a common condition that affects physical and mental health and can interfere with a person's ability to carry out daily activities. There is a range of treatments and support services available to help people recover.…
Seasonal affective disorder
What is seasonal affective disorder
Seasonal affective disorder is a type of depression that is related to the different seasons. Generally a person with seasonal affective disorder will experience periods of depression that begin and end in a certain season. It is thought to be related to the amount of sunlight a person is exposed to.
The most common type of seasonal affective disorder occurs during the winter months. This is known as winter-onset seasonal affective disorder and is more common in countries that have very short days in winter.
The exact causes of seasonal affective disorder are not clear. It is thought to be associated with a lack of exposure to sunlight during the shorter days of the year. The amount of sunlight that is passed through the eyes to certain regions of the brain directly affects the levels of particular hormones and neurotransmitters in the brain.
The reduced levels of sunlight associated with the winter months can lead to higher-than-normal levels of the hormone melatonin. Melatonin is involved in regulating sleep patterns, and when it is produced in higher amounts, it can lead to sleepiness and decreased energy levels.
Serotonin is a chemical messenger in the body involved in the regulation of mood, appetite and sleep. The production of serotonin is related to the amount of sunlight that passes through the eyes. In the winter months, the limited sunlight results in less serotonin being produced, which may trigger depression.
The body uses sunlight to set its regular biological functions and processes, such as regulation of sleep, appetite, mood and energy. This regulation is known as the circadian rhythm, or biological clock, which usually occurs over a 24-hour cycle. When there is a change in the amount of exposure to sunlight, this rhythm is disrupted and is associated with some of the symptoms of seasonal affective disorder.
Although there is no single gene associated with the onset of seasonal affective disorder, genes are thought to play a role, and people with a family history of depression may be more likely to experience seasonal affective disorder.
Adverse childhood experiences
For some people, experiencing a traumatic childhood event such as abuse or neglect may cause the onset of their seasonal affective disorder.
Summer-onset seasonal affective disorder
Although seasonal affective disorder usually begins during the winter months, some people may experience periods of depression that are associated with the summer months. As well as changes to the circadian rhythm (see above), summer-onset seasonal affective disorder may sometimes be triggered by other factors including:
- A disruption to routine due to the holiday season;
- The humidity and heat making normal functioning unpleasant;
- Body-image issues related to having to wear less clothing during the warmer weather, and;
- Financial concerns associated with family holidays.
Factors that may increase a person's chance of developing seasonal affective disorder include:
Signs and symptoms
The main symptom of seasonal affective disorder is a period of depression that begins and ends during a specific season every year, usually autumn or winter (winter onset), but occasionally spring or summer (summer onset). Usually a person with seasonal affective disorder will not experience any symptoms beyond the problematic season.
During a period of depression, a person with seasonal affective disorder may experience a range of behavioral and physical symptoms, or have certain thoughts and feelings:
A person with seasonal affective disorder may be likely to:
- Want to stay at home, rather than go out;
- Stop doing usually enjoyable activities;
- Withdraw from family and friends;
- Have trouble concentrating;
- Not get much done at work or school, and;
- Experience irritability or agitation.
Physical symptoms may include:
- Extreme tiredness;
- Difficulty sleeping, or sleeping too much;
- Change in weight;
- Change in appetite, and;
- Headaches and muscle pains.
Thoughts and feelings
During periods of depression, a person with seasonal affective disorder may feel like they are a failure, or that life is not worth living. They may also lack confidence, have difficulty making decisions, experience feelings of disappointment or feel overwhelmed.
For some people these feelings may be mild, while in others they may be very severe and cause a person to have trouble carrying out everyday tasks.
Methods for diagnosis
To diagnose seasonal affective disorder, a doctor may ask a person about their medical history and the type, onset and duration of symptoms. In some cases a doctor may order some laboratory tests.
Seasonal affective disorder may be diagnosed when:
- Symptoms begin and end during a specific season every year;
- Symptoms have occurred for a minimum of two years, and;
- No symptoms are experienced beyond the problematic season.
Types of treatment
There are several ways to treat seasonal affective disorder. Treatment may involve a combination of light therapy, medication, psychotherapy and self-care treatments.
Light therapy, or phototherapy, involves exposing a person to a very bright light, typically from a special fluorescent lamp, for 30-90 minutes a day during winter. This is usually done early in the morning, to mimic sunrise.
The intensity of light treatment depends on the power of the light source being used and how far it is placed from the person. This is expressed in a unit of measure of illumination called lux. The light used in light therapy is typically in the order of 10,000 lux, which is around 10 times brighter than sunlight an hour before sunset. At the intensity of 10,000 lux, spending just 15 minutes in front of the light provides the exposure equivalent of two hours outside in the sun.
Psychotherapy is sometimes referred to a 'talking therapy' and describes the process of treating a mental health condition by helping a person to understand their condition and manage their symptoms. If someone has depression, meeting regularly with a therapist to discuss their thoughts and feelings, and any problems they may be having, may help them manage their condition.
Antidepressant medication may be prescribed to people with more severe forms of seasonal affective disorder, or for those for whom light therapy is ineffective. Antidepressants help to control mood by restoring the balance of chemicals in the brain, such as serotonin and dopamine.
Antidepressant medications generally need to be taken for at least two weeks before any improvement in symptoms is seen. Medication may also need to be continued for a time even after the symptoms have gone, to prevent them from coming back. When stopping antidepressant medication, the dose usually needs to be reduced gradually over time, in consultation with a doctor, to prevent any withdrawal responses.
As with most medications, some people may experience side effects when taking antidepressants. Some common side effects include nausea, dizziness, tiredness and sexual dysfunction. Some antidepressants can have more serious side effects if they are taken with certain other medications or herbal remedies, or when combined with alcohol. A person's doctor will work with them to find the medication that is best for them.
Very rarely, some antidepressants may increase suicidal thoughts and the risk of suicide. The risk is highest in the first week after starting antidepressant treatment, or when the dose of the antidepressant is changed. If someone experiences suicidal thoughts, it is important to contact a doctor immediately.
Simple things that can be done at home to help manage seasonal affective disorder include:
- Increasing general exposure to sunlight by taking long walks outside during the daylight hours (for winter-onset seasonal affective disorder);
- Getting early-morning sunlight, which effectively shifts the body clock forward for summer-onset seasonal affective disorder;
- Adjusting work or a home office to be closer to a natural source of sunlight;
- Maintaining good sleep patterns;
- Eating a balanced diet;
- Regular exercise, and;
- Avoiding alcohol and other drugs, which may worsen depression.
If it is left untreated, the symptoms of seasonal affective disorder may become severe, with extreme cases having a risk of suicide. Other potential complications include:
- Substance abuse;
- Social withdrawal, and;
- Impaired school or work performance.
With treatment, the outlook for people with seasonal affective disorder is generally good. Most people eventually get better and return to their normal daily activities. However, recognizing the signs and getting treatment early may help them get better sooner. Some people may need ongoing treatment, as their condition may return with the problematic season.
Although there are no clear ways of preventing seasonal affective disorder, individuals who are prone to it may benefit from the following measures:
- Beginning light therapy before the onset of winter months;
- Spending time outside every day, even if it is cloudy (for summer-onset cases, spending time outside in the early mornings);
- Eating a well-balanced diet;
- Exercising regularly, and;
- Avoiding social withdrawal.
If you or someone you know needs help, please call or visit:
Support Groups - Online Support Groups Call 1-800-273-TALK or Text MHA to 741741
National Suicide Prevention Lifeline Lifeline Call 1-800-273-8255
The Lifeline provides 24/7, free and confidential support for people in distress, prevention and crisis resources for you or your loved ones, and best practices for professionals.
- Signs of Seasonal Affective Disorder. Health.com. Accessed October 23 2014. link here
- Board A. D. A. M. Editorial. “Seasonal Affective Disorder.” PubMed Health March 8 2013. link here
- Choices N. H. S. “Seasonal Affective Disorder - NHS Choices” September 10 2014. link here
- Depression.” Better Health Channel. Accessed October 23 2014.
- How to Deal with SAD (seasonal Affective Disorder) - Women’s Health & Fitness.” Accessed October 23 2014. link here
- myDr. “Seasonal Affective Disorder - myDr.com.au.” Resource. Accessed October 23 2014. link here
- Seasonal Affective Disorder.” Text. Accessed October 23 2014. link here
- Seasonal Affective Disorder | Definition & Patient Education.” Accessed October 23 2014. link here
- Seasonal Affective Disorder | Psychiatry.org.” Accessed October 23 2014. link here
- Seasonal Affective Disorder (SAD) Prevention - Diseases and Conditions - Mayo Clinic.” Accessed October 23 2014. link here
- Seasonal Affective Disorder (SAD)-Topic Overview.” Accessed October 23 2014. link here
- Seasonal Affective Disorder: Summer Triggers Rare Form of Depression.” AccuWeather. Accessed October 23 2014. link here
- Seasonal Affective Disorder Symptoms Causes Treatment - What Causes Seasonal Affective Disorder?” MedicineNet. Accessed October 23 2014.
- link here
- Seasonal Depression (SAD) | Center for Behavioral Health.” Cleveland Clinic. Accessed October 23 2014. link here
FAQ Frequently asked questions
What is seasonal affective disorder?
Seasonal affective disorder is a form of depression that is associated with the start of a particular time of year. The vast majority of cases are associated with the start of winter.
What are the symptoms of seasonal affective disorder?
The symptoms may be similar to those of depression and may include: feeling sad; feeling anxious; having feelings of worthlessness, guilt or hopelessness; becoming easily irritated or angry; losing interest in activities that normally …
What causes winter-onset seasonal affective disorder?
Although the exact cause of winter-onset seasonal affective disorder is not clear, it is thought to be due to changes in the levels of specific hormones and neurotransmitters in the brain and changes to the biological clock.
Who gets seasonal affective disorder?
Seasonal affective disorder is more common in younger adults and in women. There is also a genetic link to the condition, meaning that it tends to run in families.
How is seasonal affective disorder diagnosed?
The diagnosis of seasonal affective disorder is based on a person experiencing depressive-like symptoms for at least two years, with the symptoms being isolated to the specific season, i.e., winter-based seasonal affective disorder only causes …
How is seasonal affective disorder treated?
The main types of treatment for winter-onset seasonal affective disorder includes light therapy, lifestyle modifications and, in more severe cases, taking antidepressant medication.
What can be done at home to treat seasonal affective disorder?
To help manage the symptoms of seasonal affective disorder, apart from undertaking light therapy, lifestyle changes can be made that may include eating a balanced diet, seeking daily sunlight exposure, getting the right amount …
What is the outlook for seasonal affective disorder?
With proper treatment, seasonal affective disorder usually has a good outcome. Some people may need ongoing treatment, as their condition may persist throughout their lifetime.
How common is seasonal affective disorder?
Winter-onset seasonal affective disorder is more common in countries farther from the equator and summer-onset seasonal affective disorder is more common in countries closer to the equator. In Australia, winter-onset seasonal affective disorder is …