Seasonal Affective Disorder (SAD)

Many people go through short periods where they feel sad or different than usual. Sometimes, these mood changes begin and end with the changing seasons or times of the year. The relationship with seasonal changes, especially the decrease in exposure to sunlight during the winter months, is a distinctive feature of Seasonal Affective Disorder (SAD).
The lack of natural light can affect the biological clock and sleep patterns, as well as influence serotonin and melatonin levels, neurotransmitters related to mood. People may start feeling sad when the days shorten in the fall and winter, which is also called «winter blues.» They begin to feel better in the spring when there are more hours of sunlight.

SAD is a type of mood disorder that is related to seasonal changes in sunlight. The symptoms of SAD are similar to those of major depression:
Continuous sadness
Trouble concentrating
Fatigue and lack of energy
Changes in appetite (too much or too little)
Feelings of hopelessness or helplessness
Sleepiness
Social isolation
Loss of interest in activities previously enjoyed
Irritability
On the other hand, there are fewer common cases of people experiencing depressive symptoms in spring or summer. For seasonal affective disorder with a summer pattern, additional specific symptoms may include:
Difficulty sleeping (insomnia)
Loss of appetite, resulting in weight loss
Feeling restless and agitated
Anxiety
Episodes of violent behavior

What treatment is effective for SAD?
Light therapy – exposure to bright light, especially during the early morning hours
Psychotherapy – Cognitive Behavioral Therapy to identify and change thought patterns that may affect the individual’s emotional and behavioral state
Antidepressant medications – under medical supervision
Vitamin D – consult with a healthcare professional
Exercise
Stress management activities
References:
Seasonal affective disorder – National Institute of Mental Health (NIMH)