With short days and less exposure to sunlight, everyone feels less energetic and more vulnerable to depression. Seasonal Affective Disorder, known as SAD or winter depression, is a mood disorder related to seasonal changes in sunlight.

Symptoms often last until April or early spring. SAD affects between 10 to 20% of Americans, primarily younger adults and women. Although the exact cause of SAD is unknown, experts believe changes in melatonin and serotonin levels (brain chemicals), or a disruption in the body’s internal clock may be to blame.

Dr. John Stracks of Northwestern Medicine says there are ways to beat the blues caused by SAD. He suggests those who experience symptoms visit their doctor before symptoms become severe. Symptoms include feeling low and slow, difficulty waking up in the morning, sleeping more, mid-afternoon blahs, increased appetite, and loss of interest in activities.

The primary treatment for SAD is morning bright light therapy, which has several decades of research to support its usefulness.

For most people who have mild symptoms that do not interfere with functioning, try small things to keep moods balanced:

•  Sleep well – Make sure to wake up and go to bed at the same time every day, including weekends. Doing so will keep the body’s internal clock in sync.

•  Let the light in – Get as much exposure to sunlight as possible by opening the blinds at home and making sure that work space has natural or   bright light.

•  Control cravings – Eat a balanced diet while limiting the amount of carbohydrates consumed. Carbs can provide a short-term energy boost but leave you feeling worse later in the day.

•  Embrace an exercise routine – Exercise is not only good for physical health, but also helps relieve the stress and anxiety that can increase the symptoms  of SAD.

•  Learn to manage stress – Take time to relax each day and try to manage stress so it doesn’t lead to depression and overeating.