For some individuals, episodes of depression recur every year at the same time. For most people with this type of depression, the symptoms begin in the fall and continue through the winter. The shorter days of gray, cloudy weather and lack of sunshine have both a psychological and physiological impact that triggers the depression. A smaller percentage of individuals, however, may experience their recurring episodes during the spring or summer.
This type of seasonal depression is known as “Seasonal Affective Disorder”, or SAD for short. Typically, the symptoms start out mild and become more intense as the season progresses.
Symptoms of SAD
With SAD, the symptoms are different depending on the time of year the depression occurs. Symptoms for those who struggle with fall / winter depression are very similar to those of major depressive disorder (MDD). They include:
- Depressed mood
- Sense of hopelessness
- Hypersomnia (sleeping excessively)
- Decreased energy
- Decreased interest in things you normally enjoy
- Weight gain
- Appetite changes (often include cravings for carbohydrate-rich foods)
- Poor concentration
- Withdrawal from social interaction
For those who become depressed during the spring or summer, symptoms include:
- Difficulties sleeping
- Weight loss
- Irritable mood
- Increased libido
- Decreased appetite
Causes of SAD
The winter version of SAD is much more common, and more likely to be diagnosed because the symptoms are more easily identified. The exact cause is not known, but most experts believe that hormonal changes play a significant role. Serotonin, a chemical in the brain that helps regulate mood, appetite, and sleep, is believed to decrease during the months when there is less sunshine. Since serotonin helps boost mood, lower levels can lead to depression, low energy, weight gain, and cravings for foods high in carbohydrates. Carbohydrates help increase serotonin levels.
The decrease of sunshine during the winter also impacts the body’s circadian rhythms – which regulate your sleep patterns. When these are disrupted, depression may result. Melatonin levels are also disrupted when the seasons change. Melatonin is an important hormone that impacts both mood and sleep.
It shouldn’t come as much surprise that SAD is much more common in locations further from the equator, where there is less sunshine during the winter.
Risk Factors for SAD
You may have a greater risk of developing SAD if:
- You have a family history of depression
- You are female
- You already have major depressive disorder or bipolar disorder (seasonal changes can make either of these worse)
- Live somewhere significantly north or south of the equator, where sunshine is limited during the winter and summer days are long
Treatment for SAD
As with other types of depression, the treatment for SAD may include a combination of psychotherapy and medication. However, with SAD, a therapy known as phototherapy or light therapy is an important part of treatment, as it is often very effective.
Light Therapy – Light therapy, or phototherapy, utilizes a special type of light box that imitates natural light. This type of therapy is important in the treatment of SAD. Light therapy involves daily sessions in which you sit just a couple feet from the bright light. The light helps balance brain chemicals that affect mood and re-adjust your circadian rhythms. This helps reduce symptoms of depression. The benefits of light therapy often start to take place within the first few days.
Psychotherapy – Even though hormones and brain chemistry are believed to play a significant role in SAD, psychotherapy can help you make necessary changes in your actions and thoughts that may be contributing to your depression. A skilled therapist can also help you develop effective coping skills and learn how to manage the stress that is an inevitable part of life.
As with all types of depression, cognitive behavioral therapy (CBT) is one of the most effective types of therapy for SAD. CBT helps you identify and change irrational thought patterns and beliefs that contribute to depression.
Medication – If the symptoms of SAD are severe, antidepressant medication may be necessary. The most common types of medications for SAD are SSRIs – such as Zoloft or Paxil – or an SNRI like Effexor. SSRI stands for “selective serotonin reuptake inhibitor”. SSRIs primarily target serotonin. SNRI stands for “serotonin-norepinephrine reuptake inhibitor” and target both serotonin and norepinephrine (another brain chemical that affects mood). Other types of antidepressants may also be prescribed.