SAD is a condition affects about 2-3% of the general population and describes those who have clinical depression only during the autumn and winter months. Symptoms include depression, difficulty sleeping, poor appetite, difficulty concentrating and functioning at work, extreme fatigue and even suicidal thoughts.
Reduced exposure to sunlight has prompted the recommendation of phototherapy as a means to treat SAD. Phototherapy provides broad-spectrum light that includes wavelengths between 280-320 nm which allow the skin to produce vitamin D. Vitamin D deficiency is known to be very common in North America and recent media attention has highlighted the need to supplement with vitamin D for a number of reasons including: cancer prevention, treatment of some autoimmune conditions, and in this instance, the treatment of SAD.
A 1999 study published in the Journal of Nutritional Aging compared the efficacy of vitamin D versus phototherapy for the treatment of SAD using the Hamilton Depression scale. The results of this prospective, randomized controlled trial indicated that all the subjects that received vitamin D improved in all treatment outcome measures while the group that received phototherapy showed no significant change in the measures of depression. Blood levels of vitamin D improved in both groups, however, there was a 74% increase in blood levels within the vitamin D group versus only 36% in the phototherapy group. The authors also concluded that improvements in vitamin D status was significantly associated with improvement in depression scale scores and that vitamin D may be an important treatment for SAD.
In addition to vitamin D supplementation, researchers have been studying the effects of deficiencies in omega-3 essential fatty acids on the brain. It has been suggested that alterations in mood regulating brain chemicals such as serotonin and dopamine levels is often evident in an omega-3 deficient diet. Finally, omega-3 deficiency may cause significant reduction in the levels of phosphatidylserine in the brain; this is relevant considering that phosphatidylserine has documented antidepressant activity in humans.
If you or someone you know suffers from SAD, consult with your healthcare provider to ensure that your healthcare goals are addressed and some form of treatment plan can be put into place.
