Millions of Americans are affected each year by SAD — seasonal affective disorder. It’s a serious issue and shouldn’t be dismissed as “just a case of the winter blues.” SAD is most common during these gray winter months, especially in parts of the world like ours, far from the equator. The Mayo Clinic warns that you’re especially at risk if you’re female and if you or your family have a history of depression or similar mental health problems.

According to the Mayo, symptoms of SAD include: depression, hopelessness, anxiety, loss of energy, a “leaden” feeling in the arms or legs, social withdrawal, oversleeping, loss of interest in activities you once enjoyed, appetite changes (especially a craving for foods high in carbohydrates), weight gain and difficulty concentrating. You might also think about hurting yourself or drink alcohol frequently to try to feel better.

If you experience any of these symptoms for days at a time, you should get in touch with your doctor ASAP. SAD can be effectively treated using light therapy (spending time in front of a lamp that mimics the effects of the sun; your health insurer may offer discounts on such sunlamps), medication and psychotherapy. Exercise, spending time outside and maintaining a more brightly lit atmosphere can also help.

For more information about SAD, check out the Mayo Clinic’s website.