What is Seasonal Affective Disorder?

SAD can be difficult to diagnose. In some cases, there may be a lack of noticeable external symptoms. Some symptoms of SAD are caused by a lack of proper diet, exercise and effort. It is often dismissed as being all in a person's head.

Though chronic, consistent fatigue may manifest visibly, symptoms of SAD may be primarily mental and emotional. Many patients are debilitated by psychological symptoms.

6% of Americans suffer from serious SAD.

14% of Americans suffer from a less serious form of holiday blues.

Women are four times more likely to have SAD than men.

During the winter months, there are dramatically fewer hours of daylight and sunshine. This lack of sunshine leads to a lower production of serotonin, which causes issues with mood regulation. Studies have even suggested disruptions in melatonin as a cause of SAD. 

There's no doubt changing seasons may lead to changing symptoms. If you’ve noticed a change in your mood or energy levels, here are a couple of symptoms to look out for:


People with seasonal affective disorder experience a shift in mood that begins at the end of fall or the start of winter. Activities may seem less pleasurable, and disinterest and disconnection become more common. For some, this may cause sluggishness or an easily agitated temperament. Suicidal thoughts may be more common, too.

Weight Fluctuations

SAD is associated with weight gain and weight loss, depending on the individual reaction. It is also one of the more visible symptoms. Mood-related disorders may cause a loss of appetite or an increase in appetite. People may depart from their regular diet and begin to crave foods high in carbohydrates.

Disturbed Sleep 

Some people may not feel rested despite adequate hours of sleep. Difficulty falling asleep, staying asleep, or other abnormal sleep patterns may arise. Conversely, oversleeping is also a possible symptom of SAD. 

People with SAD report sleeping an average of 2.5 hours more in winter than in the summer, according to an interview published in the journal Psychiatry.

Chronic Fatigue

Activities like grocery shopping, paying bills, or showering may become difficult. Weakness and low energy levels are common, which can affect the ability to work or maintain relationships. Note: It's important to differentiate seasonal fatigue with chronic fatigue, which may be related to an autoimmune disease or brain/spinal cord inflammation.

Brain Fog

Difficulties with brain function can be hard to recognize, but it's often described as a lack of sharpness. Brain fog is associated with memory issues, and an inability to recall details. It causes concentration problems which may affect overall productivity and creative output. 

During this time, we lean towards introspection and reflection. We begin to analyze all we’ve accomplished and all we’ve yet to accomplish.

Once you've identified you're in a seasonal funk, arm yourself with crucial knowledge and sage advice that lets you focus on self-care. In the United States, SAD commonly begins in December and ends in April, though each individual may experience it differently. 

SAD is still stigmatized, but medical professionals have options for treatment. Some treatments include light therapy (phototherapy) or medication. Talk to your doctor about your symptoms to learn more about tailored options to treat SAD.