Seasonal Affective Disorder Causes

(Also Known As: Seasonal Affective Causes, Depression Causes, SAD Causes, Seasonal Mood Disorder Causes)

(Reviewed by: Paul Peterson, Licensed Therapist)

What Causes Seasonal Affective Disorder?

According to most experts, the depression being felt by individuals suffering from seasonal affective disorder is caused by the reaction of the brain to decreased exposure to daylight. No one can really explain the reason for such occurrence. Current studies on the cause of seasonal affective disorder believe that the sun plays a crucial role in the ability of the brain to produce key hormones.

Experts believe that the chemicals melatonin and serotonin may have a role in the development of seasonal affective disorder. These two hormones are responsible for the regulation of an individual’s sleep and wake cycle, mood, and energy level. The shorter days and longer nights during winter bring about an increase in the level of melatonin and depletion in the supply of serotonin, leading to the depression.

The chemical melatonin is related to the sleep cycle of an individual. At night when there is no sunlight, there is an increased production of melatonin. As a result, it would lead to the individual becoming lethargic and sleepy.

The chemical serotonin works in a slightly different manner. During the day, the production of serotonin is higher so an individual will have decreased serotonin levels during the winter. In order to combat depression, the level of availability of serotonin should be increased.

The specific factors that can be a cause seasonal affective disorder are still not known. It is believed that the age, state of mental health, and natural chemical makeup of an individual has an impact in the development of seasonal affective disorder. 4

Studies also believe that the reduction of sunlight during the fall and winter months may disrupt the circadian rhythm in certain people. This is a process that helps in the regulation of an individual’s internal clock—reminding them when to go to sleep or wake up. Any disruption in the circadian rhythm can lead to depression on the part of the individual.

Could You Have Seasonal Affective Disorder?

Seasonal Affective Disorder Topics

Related Conditions

Adjustment Disorder – psychological response to a known stressor, emotional changes
Anxiety Disorder NOS – pathological fear and anxiety, chronic anxiety, panic disorder, phobias
Bipolar Disorder – psychosis, hallucinations, delusions, suicide, hypomania, hypermania