The 411 on SAD

What is SAD?

SAD stands for Seasonal Affective Disorder, a type of depression affecting people when the seasons change. Symptoms may start mildly, but they could become more severe as the season progresses.

There’s no specific cause of SAD, but when the seasons change, our biological clocks (circadian rhythm) get disrupted. The levels of serotonin (a brain chemical responsible for mood, or feeling good) and melatonin (a natural hormone produced in the brain that regulates our sleep pattern) decrease as we spend more time indoors where there is less natural sunlight.

SAD tends to affect women more than men. If you are diagnosed with depression or other mood disorders, you may suffer more acutely from SAD. 

What are the signs of SAD?
  • Lack of energy or tiredness
  • Feeling depressed most of the day or every day
  • Trouble sleeping (insomnia) or oversleeping
  • Weight gain or poor appetite
  • Losing interest in the things you enjoy
  • Anxiety
  • Difficulty concentrating 
  • Feeling hopeless or unworthy


When should you see a doctor?

It’s normal to need time to adjust to seasonal changes, but if the SAD symptoms you are experiencing worsen, please call your doctor for an appointment. Here are some resources that can help you practice self-care while you experience SAD symptoms. 

Light Therapy

Light therapy, or phototherapy, is controlled exposure to daylight as a treatment to reduce the symptoms of SAD. A light therapy box or sun lamp mimics natural daylight, thus lifting your mood. It can help reset your biological clock. Light therapy is safe to use, however it may take a few weeks for SAD symptoms to lessen. 

Check out these light therapy overviews from the Mayo Clinic and the University of Michigan.

Library Resources 

Winter Blues (e-book) – If you suffer from Seasonal Affective Disorder, this book can help with tips to feel more energized and productive all year long.

Defeating SAD (Seasonal Affective Disorder) – This book provides advice on how to identify, treat and overcome both winter and summer varieties of Seasonal Affective Disorder, as well as the less severe yet bothersome "winter blues." Also available as an e-book.