Seasonal Affective Disorder (SD) is a type of major depression that occurs in specific times of the year. While Seasonal Depression is considered to be a sub-type depression, studies show that SD turn into non-seasonal major depression in 33-44% of the cases.
What are the Symptoms of Seasonal Depression?
Seasonal depression is sometimes called “winter depression” on occasion. Because symptoms generally start and grow worse in the fall/winter period. The symptoms typically disappear in the spring/summer months, yet some people may experience the symptoms in the summer months as well. There is also a rare type of depression known as “summer depression”, which starts by the end of the spring and ends in the fall.
The Seasonal Depression diagnosis is based on regular cycles of depression in the fall/winter months, along with the symptoms that typically diminish in the spring/summer months and the seasonal symptoms that occur at least two years in a row.
People with Seasonal Depression experience non-seasonal depression-like mood changes and symptoms, including the following:
- An apparent loss of attention and joy in daily activities
- Low motivation
- Low energy, and tiredness
- Feeling worthless or guilty
- Low libido
- Impaired concentration
- A bad temper
The Seasonal Depression experienced in the winter months has a specific cluster of characteristic indications. Increasing sleepiness with the urge to sleep during daytime; an increase in appetite particularly for carbohydrates; and weight gain. Furthermore, it may deteriorate the functionality of the person.
Why does Seasonal Depression occur?
The causes of seasonal depression have not been fully comprehended. Nonetheless, researchers have associated SD with being less exposed to sunlight in the spring and winter days.
The most deep-rooted theory is the fact that the sunlight causes hormonal changes in the brain. Being less exposed to sunlight may cause a biochemical imbalance by preventing the proper functioning of the hypothalamus. For instance, there might be a decrease in the production of serotonin, which is the “happy chemical” in our brain, regulating our mood.
Our state of mind, our levels of energy and our appetite can get affected following the deterioration of the neural pathways affecting the emotional regulation. In people with SD, the brain might be overproducing the melatonin, which is known as the “sleep hormone” associated with the commencement of the sleep. Low levels of sunlight might be leading to SD symptoms by breaking the natural circadian rhythm of the body.
In the USA, 6% of the adults suffer from major depression that is accompanied by seasonal depression. The mean age for the initial appearance of seasonal depression in an individual is 27. SD has the highest prevalence in women in reproductive age; this disease is four times more prevalent in women than in men. The prevalence rates tend to decrease in advanced ages; women and men over the age of 65 are affected equally.
SD is less prevalent in children, with similar rates in girls and boys. The disease seemingly has a genetic component as well. If an immediate family member is affected, the occurrence of seasonal depression is more likely. Countries receiving sunlight throughout the year have less SD rates. Moreover, you will have a less chance to have SD as you move away from the equator.