Seasonal Depression (Seasonal Affective Disorder)

Overview 

Seasonal affective disorder (SAD) is a type of depression that's related to changes in seasons — SAD begins and ends at about the same times every year. If you're like most people with SAD, your symptoms start in the fall and continue into the winter months, sapping your energy and making you feel moody. These symptoms often resolve during the spring and summer months. Less often, SAD causes depression in the spring or early summer and resolves during the fall or winter months.

Treatment for SAD may include light therapy (phototherapy), psychotherapy and medications.

Don't brush off that yearly feeling as simply a case of the "winter blues" or a seasonal funk that you have to tough out on your own. Take steps to keep your mood and motivation steady throughout the year.

Symptoms

In most cases, seasonal affective disorder symptoms appear during late fall or early winter and go away during the sunnier days of spring and summer. Less commonly, people with the opposite pattern have symptoms that begin in spring or summer. In either case, symptoms may start out mild and become more severe as the season progresses.

Signs and symptoms of SAD may include:

Symptoms of SAD most commonly begin around late fall or early winter and end in the spring. However, it’s possible to experience symptoms at other times of the year. You also may not experience the condition every year.

• Feeling listless, sad or down most of the day, nearly every day 
• Losing interest in activities you once enjoyed
• Having low energy and feeling sluggish
• Having problems with sleeping too much
• Experiencing carbohydrate cravings, overeating and weight gain
• Having difficulty concentrating
• Feeling hopeless, worthless or guilty
• Having thoughts of not wanting to live

Fall and winter SAD

Symptoms specific to winter-onset SAD, sometimes called winter depression, may include:

• Oversleeping
• Appetite changes, especially a craving for foods high in carbohydrates
• Weight gain
• Tiredness or low energy

Spring and summer SAD

Symptoms specific to summer-onset seasonal affective disorder, sometimes called summer depression, may include:

• Trouble sleeping (insomnia)
• Poor appetite
• Weight loss
• Agitation or anxiety
• Increased irritability

Seasonal changes and bipolar disorder

People who have bipolar disorder are at increased risk of seasonal affective disorder. In some people with bipolar disorder, episodes of mania may be linked to a specific season. For example, spring and summer can bring on symptoms of mania or a less intense form of mania (hypomania), anxiety, agitation and irritability. They may also experience depression during the fall and winter months.

When to see a doctor

It's normal to have some days when you feel down. But if you feel down for days at a time and you can't get motivated to do activities you normally enjoy, see your health care provider. This is especially important if your sleep patterns and appetite have changed, you turn to alcohol for comfort or relaxation, or you feel hopeless or think about suicide.

What is seasonal affective disorder?

Seasonal affective disorder (SAD) is another term for major depressive disorder (MDD) with seasonal pattern. It’s a type of depression that’s provoked by seasonal change. Usually, symptoms begin in the fall or winter.

The condition affects between 0.5 and 2.4 percent of people in the United States. SAD most often occurs in women and young adults, particularly those who live farther north.

Risk factors

People who live in areas that have long winter nights (due to higher latitudes) and less sunlight are more likely to experience SAD. For example, the condition is more common in Canada and Alaska than in sunnier Florida.

The condition occurs more frequently in women than men, and it’s most likely to begin in younger adults between the ages of 18 and 30.

People with a family history of SAD and other psychological conditions are at greater risk for SAD.

Additionally, individuals with other mental health conditions are more likely to experience SAD. Around 25 percent of people with bipolar disorder and between 10 to 20 percent of people with major depressive disorder also have SAD.

Light Therapy

Another treatment for wintertime SAD is light therapy. This involves using a specialized light box for at least 30 minutes each day during the winter to replicate natural light.

Side effects of light therapy may include dizziness, eye fatigue, or headaches. You may need to avoid light therapy if you:

• have certain eye diseases
• recently had eye surgery
• are sensitive to light due to other medications
• have bipolar disorder

Another similar treatment option is a dawn simulator. It uses a timer-activated light to mimic the sunrise, which helps to stimulate the body’s clock.

Light therapy should be used only under a doctor’s supervision and on approved devices. This therapy may work best in combination with other treatments, like medications.

Side effects of Light therapy

Some people shouldn’t use light therapy, especially those who:

• have medical conditions that make eyes sensitive to light
• take medications, like some antibiotics or antipsychotics, that increase light sensitivity

If you’re considering this therapy, you should consult a doctor if you have any of the following conditions:

• sensitive skin
• eye conditions
• a history of skin cancer

Some people may also experience euphoria or irritability, which is a sign to stop using the device and speak with a doctor.

For those who can use light therapy, there are still potential side effects. Usually, these can be dealt with by adjusting the duration, intensity, or timing of the sessions.

Side effects may include:

• headaches
• eyestrain
• agitation
• irritability
• problems with sleeping
• fatigue
• blurry vision

You can discuss these side effects with a doctor, but you may also find relief through some simple changes. Avoid using the lamp before bedtime to prevent insomnia, and place the light box further away from you to prevent eyestrain and headaches.

Outlook

If you regularly feel depressed and have difficulty sleeping during certain seasons, especially the winter, you may be experiencing SAD.

Treatments like counseling, medications, and light therapy are often effective for reducing SAD symptoms. Increasing your exercise and natural light exposure may also help.

If you have symptoms of SAD, talk with your doctor. They can work with you to create a treatment plan to best manage the condition.

How to do light therapy at home

Before you start light therapy, it’s a good idea to talk with a doctor or mental health professional. Light therapy may interact with other treatments you’re currently taking, such as medications.

Once you’ve had a doctor’s sign off, you can start by reading the instructions provided by the light box manufacturer.

A light with lower intensity may require longer exposure time — meaning you’ll have to sit in front of the box longer. The instructions can also help you identify specific risks and hazards for the brand of the light.

To use a light therapy lamp with 10,000 lux intensity, follow these steps:

• Place the lamp on a counter, desk, or other surface.
• Sit or stand at the correct distance from the lamp according to the manufacturer’s instructions.
• Keep your eyes open and do not sleep during light therapy sessions.
• Do not stare directly at the light box or lamp.
• Start with 30 minutes of exposure per day.
• Schedule light therapy sessions as soon as possible after waking up, between 6:00 a.m. and 9:00 a.m.

You can adjust this schedule and the duration of sessions according to how you feel. You can also try passing the time in front of the light box with an activity like reading a book or working, as long as you’re still facing the light.