Seasonal affective disorder is a type of depression that lasts for a season, typically the winter months or only in summer, and goes away during the rest of the year. Because the symptoms of SAD are frequently more pronounced and severe during the winter months when there is less sunshine and typically get better with the approach of spring, the condition is sometimes referred to as “winter depression.” The symptoms may be distressing and debilitating and may make it difficult to go about regular activities.

SAD has been linked to a biochemical imbalance in the brain prompted by shorter daylight hours and less sunlight in winter. As seasons change, people experience a shift in their biological internal clock or circadian rhythm that can cause them to be out of step with their daily schedule. 

There are two types of SAD:

• Fall-onset:
  This is also called “winter depression.” Symptoms of depression begin in the late fall to early winter months and ease during the summer months.
  
  
• Spring-onset:
  This is also called “summer depression.” Symptoms of depression begin in late spring to early summer. This type is much less common.
  
  

Symptoms

The following are the most common symptoms of SAD:

• • Increased sleep and daytime drowsiness

• • Loss of interest and pleasure in activities formerly enjoyed

• • Social withdrawal and increased sensitivity to rejection

• • Irritability and anxiety

• • Feelings of guilt and hopelessness

• • Fatigue, or low energy level

• • Decreased sex drive

• • Decreased ability to focus or concentrate

• • Trouble thinking clearly

• • Increased appetite, especially for sweets and carbohydrates

• • Weight gain

• • Thoughts of death or suicide

• • Physical problems, such as headaches, stomachaches
    
    
    

    For winter-pattern SAD, additional specific symptoms may include:

• • Oversleeping (hypersomnia)

• • Overeating, particularly with a craving for carbohydrates

• • Weight gain

• • Social withdrawal (feeling like “hibernating”)
    
    
    

    For summer-pattern SAD, specific symptoms may include:

• • Trouble sleeping (insomnia)

• • Poor appetite, leading to weight loss

• • Restlessness and agitation

• • Anxiety
    
    
  • Episodes of violent behavior

Causes

While the exact causes of SAD are unclear, it’s often linked to the reduced amount of sunlight in winter. This can affect:

• Your body clock. Your body uses sunlight to regulate your sleep, appetite and mood. Lower light levels in winter can disrupt your body clock, leading to depression and tiredness.
  
  
• Your production of melatonin, a sleep hormone. People with SAD may produce much higher levels in winter.

How can we manage SAD?

• Take in as much daylight as possible.
  The lack of sun exposure is part of what causes SAD, so soaking up as much as you can may lessen symptoms. Sit by a window or go for a walk during daylight hours.
  
  
  
• Eat healthily.
  Comfort foods don’t have to be loaded with extra calories and lots of sugar and fat. Get creative and look for hearty, low-calorie recipes that are easy to prepare.
  
  
  
• Spend time with your friends and family.
  Spending time with friends and family is a great way to lift your spirits and avoid social isolation.
  
  
  
• Stay active.
  Research shows exercise and scheduling pleasant activities can be effective ways to lessen the impact of SAD.
  
  
  
• Light therapy.
  If increasing sunlight is not possible, exposure to a special light for a specific amount of time each day may help.
  
  
  
• Seek professional help.
  If you continue to struggle with feelings of depression, you may want to seek help from a mental health professional.
  
  
  
  
• References

• • American Psychological Association. (2014, December 15). Seasonal affective disorder: More than the winter blues. American Psychological Association. Retrieved December 5, 2022, from https://www.apa.org/topics/depression/seasonal-affective-disorder

• • Seasonal Affective Disorder (SAD). (n.d.). Mental Health Foundation. Retrieved December 5, 2022, from https://www.mentalhealth.org.uk/explore-mental-health/a-z-topics/seasonal-affective-disorder-sad

• • Seasonal Affective Disorder. (n.d.). Seasonal Affective Disorder | Johns Hopkins Medicine. Retrieved December 5, 2022, from https://www.hopkinsmedicine.org/health/conditions-and-diseases/seasonal-affective-disorder

• • Seasonal affective disorder (SAD) – Symptoms and causes. (2021, December 14). Mayo Clinic. Retrieved December 5, 2022, from https://www.mayoclinic.org/diseases-conditions/seasonal-affective-disorder/symptoms-causes/syc-20364651