Your Bad Mood Could Be Seasonal Depression — Here Are the Signs to Look Out For

"Seasonal affective disorder is a type of depression that affects people at the same time each year, typically over the Winter. People have a circadian rhythm, or biological clock, that is driven by serotonin and melatonin levels and can be thrown off course by prolonged dreary weather," Dr. Yeager told POPSUGAR.

According to Dr. Yeager, symptoms of SAD may include fatigue, sadness, depression, hopelessness, social withdrawal, and weight gain. "Some people may experience anxiety, loneliness, mood swings, or a loss of interest in activities they previously enjoyed," he explained. "Sleep problems, including excess sleepiness, insomnia, or sleep deprivation may occur."

Although Winter SAD is the most common type of seasonal depression, SAD can also be experienced during the Summer months. According to the National Institute of Mental Health (NIMH), Summer SAD is "less frequently occurring" with symptoms including:

• Poor appetite with associated weight loss
• Insomnia
• Agitation
• Restlessness
• Anxiety
• Episodes of violent behaviour

Now that you know the symptoms of SAD, it's important to know the demographic that is at risk for SAD.

Women are four times more likely to experience SAD than men, the NIMH reported. SAD is also more frequently diagnosed in those who live far north or south of the equator. "People with a family history of other types of depression are more likely to develop SAD than people who do not have a family history of depression," the NIMH reported on its website. Finally, younger adults have a higher risk of SAD than older adults, according to the NIMH.

If you have been diagnosed with SAD, there are multiple ways you can manage and treat your depression. Dr. Yeager recommends doing the following:

• Take a daily walk outside to boost your mood within a few hours of waking up since exercise releases endorphins, which are chemicals that create a positive, euphoric feeling in the body. It's important to walk in the morning because the morning sunlight exposure will keep your body's clock on track, Dr. Yeager explained.
• Make sure your office and home have lots of natural light. If you don't have a lot of natural light sources in your home, Dr. Yeager recommends buying a light box, which mimics natural light outdoors, and place it by your desk or chair for 30 minutes each day. "The light box turns off melatonin production and helps boost the serotonin in your body," Dr. Yeager said.
• Dr. Yeager also recommends asking your doctor about vitamin D supplementation; according to the NIMH, "the evidence for its use has been mixed."
• "Stay social and active through the stretches of cold, rain, and grey. Sign up for a class, recruit an exercise buddy, or schedule regular outings with friends," Dr. Yeager said.
• If you have the means, he also recommends taking a holiday to somewhere with lots of sun.