Many people have heard of the condition called Seasonal Affective Disorder (SAD), characterized by a depressed mood that onsets in fall and winter. SAD is not (any longer) a distinct diagnosis, but is now a commonly used term to describe a very real condition, depression with a seasonal pattern. Winter is the most common season for this, so with fall upon us and winter quickly approaching, perhaps it is helpful to take a closer look at what seasonal depression is compared to normal mood changes that might occur with the changing seasons.
Signs of Seasonal Depression
Most sufferers of seasonal depression have similar symptoms, typically beginning in fall and increasing into winter:
- Loss of interest in normally enjoyable activities
- Increased appetite, especially cravings for carbohydrates
- Weight gain
- Sadness and frequent crying
- Suffering from joint or stomach problems
- Having trouble getting up in the morning and feeling lethargic
- Lowered sexual desire and function
- Trouble concentrating
- For women, worsened premenstrual syndrome symptoms
As spring approaches, the symptoms will lessen very quickly.
Why does it happen?
There are several hypotheses on the causes of seasonal-onset depression. One of the most promising and widely accepted explanations, referred to as the “phase shift hypothesis”, is related to disruption of our “internal clocks,” or circadian rhythms. Our circadian rhythm regulates our mood and feelings. We use sunlight to maintain circadian rhythms, so winter’s long nights cause a disruption to our internal clocks, thereby disrupting our mood and feelings.
When it’s sunny outside, the brain releases serotonin, a chemical which is linked to positive emotions and feeling alert and awake. When it is dark, the brain releases melatonin, a hormone that causes drowsiness. Because the nights are much longer in wintertime, the brain usually produces less serotonin and more melatonin. For those afflicted with seasonal-onset depression, the amount of serotonin becomes drastically lower, resulting in feelings of depression and the surges of melatonin create lethargy. It is as if a person is suffering chronic jet lag, but with intense feelings of unhappiness or irritability.
Who gets it?
Since darkness is a major factor in this illness, it’s no surprise that the number of cases increase the further north you go from the equator. Overall, between 2-3% of the general population suffers from seasonal-onset depression. Women are four times more likely than men to experience it. There is no evidence linking prevalence of seasonal depression with any ethnic groups. It typically first occurs between the ages 18-30.
Depression is not the same as the “winter blues”
An estimated 15-20% of the population experience the “winter blues.” The two share characteristics, but depression symptoms are overall much more severe and persistent. For example, choosing to stay in rather than go out more often in the winter than other seasons is normal, but someone suffering depression might feel incapable of going out on a winter night, even if they want to, or are expected to (such as a family or work obligation). Moreover, feeling blue may last only a few days at most, whereas being depressed persists for sometimes weeks at a time. Depression is marked with strong feelings of hopelessness, worthlessness, and oftentimes it is difficult to hide this mood from others. At the worst, someone with depression may have suicidal thoughts or urges.
Seasonal depression is treatable
If you believe you or someone you care about suffers from seasonal depression, don’t hesitate to contact a professional to discuss your concerns. Coping skills, self-care, and certain behavioral changes can drastically improve the severity of symptoms a person experiences. Additionally, there are many proven and promising treatments, including talk therapy, antidepressants, and even light therapy.
“In the depth of winter, I finally learned that there was in me an invincible summer.”- Albert Camus
Meesters Y, Gordijn MC. Seasonal affective disorder, winter type: current insights and treatment options. Psychol Res Behav Manag. 2016;9:317-327. doi: 10.2147/PRBM.S114906