When the days begin to shorten, many people find themselves spending less time outside. This can often lead to an increase in feelings of sadness and a loss of energy, causing a form of depression called Seasonal Affective Disorder (SAD). While more common in the winter months, SAD can also make an appearance in the spring and summer months (sometimes called Reverse Seasonal Affective Disorder).

What Is Seasonal Affective Disorder?

People with Seasonal Affective Disorder exhibit symptoms of depression such as sadness, low energy, irritability, daytime tiredness, and decreased activity during particular seasons of the year.

Seasonal Affective Disorder is a type of depressive disorder which occurs when you develop symptoms of depression such as sadness, low energy, irritability, daytime tiredness, and decreased activity during particular seasons of the year. While not considered a unique diagnostic entity, experts classify SAD as a type of recurrent major depression with a seasonal pattern.

Experts are not entirely sure why some people develop SAD, but they point to a few factors including a difficulty regulating serotonin (a neurotransmitter believed to be responsible for balancing mood), an overproduction of the hormone melatonin (which regulates sleep), and a lower production of vitamin D (which is believed to play a role in serotonin activity).

SAD affects five percent of the population (16 million Americans), but the disorder may go unreported and often undiagnosed, so experts say pinpointing prevalence can be difficult. However, there are certain groups of people where SAD is more common:

  • It occurs four times more often in women than in men.
  • The age of onset is estimated to be between 18 and 30 years old.
  • Those living farthest from the equator in northern latitudes are most susceptible.
  • Family history of other types of depression.
  • Having depression or bipolar disorder.

Summer Seasonal Affective Disorder

While not as common as winter SAD, there are individuals who struggle with a seasonal disorder in the summer months. Dr. Marc Romano, PsyD, Director of Medical Services at Delphi Behavioral Health, says there have been many theories as to why people experience depression during the summer months.

One idea, Dr. Romano says, is that a change in melatonin levels occurs in the summer months which leads to changes in the body’s internal clock or circadian rhythm. He also points to an increase in pollen counts, high temperatures, and too much sunlight as possible theories.

How Is Seasonal Affective Disorder Diagnosed?

The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria for diagnosing SAD explains that people must meet full criteria for major depression which occurs during a specific season every year and that the pattern includes having these experiences for at least the last two years. It further states that no episodes of depression occur during the season in which you experience a normal mood.

Romano says in order to determine if a patient meets the DSM-5 criteria, practitioners need to ask the right questions to determine if individuals presenting with depression are in fact, suffering from a seasonal affective disorder. This can only be done by a thorough assessment of the temporal relationship between an individual’s depressive symptoms, time of year, and history.

Common Signs and Symptoms of Seasonal Affective Disorder

  • Decreased activity
  • Anxiety
  • Irritability
  • Sadness
  • Daytime tiredness
  • Overeating and weight gain
  • Loss of interest in usual activities
  • Withdraw from social activities
  • Inability to concentrate

According to Dr. Romano, individuals who experience SAD in the summer present with the opposite symptoms of those who experience SAD in the winter. These include having more energy, sleeping less, and for some people, a decrease in appetite.

Tips to Treat and Manage Seasonal Affective Disorder

Whether it occurs in the winter or summer, the presence of a seasonal depressive disorder can be debilitating. Like many other mood disorders, there are actions you can take to lessen the severity of the symptoms associated with SAD.

Seek professional help. Romano says the use of counseling is highly recommended to treat depressive disorders and would likely benefit any individual suffering from either summer or winter SAD. More specifically, the National Institute of Mental Health (NIMH) says the use of cognitive behavioral therapy (CBT) has proven to be very effective in treating SAD.

Medication. Selective Serotonin Reuptake Inhibitors (SSRIs) are sometimes used to treat SAD. The Federal Drug Administration has also approved the use of bupropion, another type of antidepressant known as an aminoketone, for treating SAD.

Light therapy. The symptoms of SAD may be relieved by the daily use of a light box. NIMH recommends sitting in front of the box, first thing in the morning, for 20 – 60 minutes. This should be done from early fall until spring.

Seek out the sun. You need to make getting outside a priority during the winter months. The lack of sun exposure is part of what causes SAD, so it’s important to spend some time outside. If mobility issues prevent you from getting outside, experts recommend keeping your blinds open and sitting by the window.

Participate in regular exercise. Physical activity has been shown to decrease the symptoms of depression. Aim for 30-60 minutes a day, five days a week, of aerobic and strength training exercises. Getting outside for some of that time will help target the specific symptoms of SAD.