By Edward Pullen, MD. Check out drpullen.com, a medical blog for the informed patient.

SAD is the acronym for seasonal affective disorder, and as we head into the long nights and short days of the northern winter, which, at least in Washington, are made even darker by overcast skies nearly every day, I see my usual patients for SAD.  Some come in with a clear history of becoming depressed, tired, irritable and even suicidal each winter, and the diagnosis is very clear.  Other patients don’t recognize the pattern, or have recently moved to the north, and it can be more difficult to recognize the problem.  At any rate, SAD is one of the problems that we have become quite good at treating, with many of the selective serotonin reuptake inhibitors (SSRI) being very effective. Some patients even feel that frequent trips to the sunny south are helpful, but for most this is not a viable option.

If you think you have SAD, there are some symptoms you should look out for. Here are the most common ones:

• Increased sleep
• Increased eating
• Loss of energy
• Not enjoying activities you usually do, including sex
• Becoming more anti-social
• Being especially anxious

Having a tougher time at work and not being able to handle as much stress as usual

SAD was really only documented and made a diagnosis after 1984, and in the last couple of decades has become better understood.  It is great that we now have SSRI antidepressants to treat this with, but many patients either prefer not to take medication, have side effects from the drugs, or just want a more natural remedy.  Full sunlight wavelength light therapy has been shown to help in these patients, and although it is neither easy nor convenient, it does have good evidence of effectiveness.  Patients can purchase lights for therapy in many shapes and sizes, or can build their own light boxes.

I came across a great post by Tara Parker-Pope in the N.Y. Times you may enjoy and learn from:

Light Therapy for Dark Days

By Tara Parker-Pope

For the millions of Americans who suffer from mild to severe winter blues — a condition called seasonal affective disorder, or S.A.D. — bright-light therapy is the treatment of choice, with response rates comparable with those of antidepressants, reports today’s Consumer column.

Many experts think light therapy is underused, given its affordability and relative lack of side effects, in large part because there is little profit to be made from it and no commercial incentive to promote the treatment.

Patients generally sit in front of the light box, which can be as small as 9 by 11 inches and 5 inches deep, with the bright light emanating from the square surface, in the morning. “With the natural dawn being later in winter, the body rhythms drift late,” Dr. Lewy said. “If you can fix the drift, you can fix the depression.”

Light therapy may even help with major nonseasonal depression, experts say, and with sleep disorders. And because it has few side effects, researchers are studying whether light therapy can help with depression during pregnancy and be used to treat elderly people with dementia. It is also being investigated for the treatment of bulimia nervosa, severe premenstrual syndrome and even attention deficit hyperactivity disorder and bipolar disorder.