What is Seasonal Affective Disorder?
When the weather is sunny and bright people tend to feel more upbeat and positive. When the weather is gloomy, cold and dismal, moods tend to slump and often people feel a little down.
However, for certain individuals these mood shifts develop into a type of depression that accompanies seasonal changes and affects their ability to function normally. Recurrent episodes of clinical depression that surface during seasonal changes, particularly winter, are referred to as Seasonal Affective Disorder (SAD).
This condition is caused by a biochemical imbalance in the hypothalamus – the part of the brain that governs the primary functions of the body such as appetite, temperature, sleep, sex drive, mood and activity.
The hypothalamus is stimulated by natural light entering the eye and striking the retina. When the days are short and sunlight is reduced, the hypothalamus has to adjust its response to the various body mechanisms, slowing down these functions.
What is Winter Depression?
A milder form of this type of depression is more commonly referred to as winter depression, winter blues, cabin fever or hibernation reaction. While winter depression can be uncomfortable, the condition is not unbearable.
The classic symptoms of winter depression include fatigue, oversleeping, carbohydrate craving, weight gain, lack of sex drive, and sometimes even hopelessness, social withdrawal and suicidal thoughts. These symptoms are similar to those of SAD - Seasonal Affective Disorder – but not as severe.
Winter depression usually begins in late fall or early winter and generally disappears by the summer (begins in October or November and subsides in March or April). It frequently affects people living in the northern geographic regions. People with winter depression are affected by the changes in environmental light such as overcast weather or dim lighting which worsens their depression.
Winter is not the only season responsible for mood slumps - a less common type of Seasonal Affective disorder is called summer depression and it usually begins in late spring or early summer and goes away by winter.