Seasonal Affective DisorderPresented to Breakfast Club on Dec. 3, 2013
Susan C. Jenkins, MD
Background:
First mentioned in literature in 6th century by Goth scholar Jordanes (per Wikipedia citing Jordanes, Getica, ed. Mommsen, Mon. Germanaehistorica, V, Berlin, 1882)
SAD was brought to the attention of NIMH researchers by Herb Kern, an engineer who had graphed his depressions for several years and noted the association with winter months. The researchers were interested in biorhythms. Kern suggested the cause might be waning light. The researchers devised a lightbox, and when Kern responded, began actively researching phototherapy for SAD.
Term was coined by Norman E. Rosenthal, MD of the NIMH. They published:
Rosenthal, Sack, Gillin, Lewy, Goodwin, et al “Seasonal affective disorder: A description of the syndrome and preliminary findings with light therapy” Archives of General Psychiatry 41(1): 72-80, 1984. Initially greeted with great skepticism, but Rosenthal and others repeatedly taught at APA.
Rosenthal also authored a book, Winter Blues, published in 1993; revised 2006.
Signs and Symptoms: SAD is characterized by:
- Increased need for sleep; difficulty getting going in the morning; over-sleeping
- Patient complains of apathy and lethargy; leaden feeling; “Gray” depression not “blue.”
- Carbohydrate craving – specifically, sweets & chocolate
- Due to above, weight gain is common
- Difficulty concentrating, difficulty with making decisions, planning and executing projects
- Social withdrawal
- Decreased sex drive
- Anxiety, depression, hopelessness
Confounding diagnoses:
- People with predisposition to depression are more likely to suffer from SAD.
- 20% of persons with SAD have bipolar disorder; 25% of bipolar have SAD (Bipolar II> Bip. I)
- Recurring stress related to seasonal worsening of psychosocial stresses (school anxiety)
Incidence of SAD is directly related to geographic distance from the equator.
- 9.5% of Finns in the northern part of the country (Arctic)
- 8.9% of Alaskans; 9.7% New Hampshire; 1.4% in Florida
Icelanders and Japanese are the exceptions to this rule – thought to be because of high rate of fish consumption. (90 and 60 kg/person/yr vs. 24 kg in the USA)
Spring and summer seasonality – “Summer depression” – per Mayo Clinic
Anxious, insomnia, irritability, agitation, weight loss, poor appetite, increased sex drive
Seasonal bipolar worsening in spring and summer:
Rapid thoughts and speech, persistently elevated mood, agitation, hyperactivity, increased enthusiasm out of proportion to situation
DSM-V: Bipolar with seasonal pattern:
“Regular temporal relationship between the onset of manic, hypomanic, or major depressive episodes and a particular time of year” – exclude cases with seasonal worsening of psychosocial stress like school starting. Full remission also occurs at a characteristic time of year. Documentation of 2 years of the pattern. Mood changes associated with the seasons “substantially outnumber” any other mood episodes that may have occurred over the individual’s lifetime.
Treatment:30-60 minutes daily, 30-60 cm from the eyes; October 15 – April 15
Light: 10,000 Lux of full spectrum (“artificial sunlight”)
2500 Lux of 480 nm blue light --- Philips Go-LiteBlu
350 Lux of 500 nm blue-green light
Sun exposure
Dawn simulation -- Effective 50% vs. 57% for bright light therapy – Philips Wake-up Light, White
Negative air ionization – Himalayan salt lamp
Vitamin D – inadequate ultraviolet rays on skin leads to deficiencies – studies mixed about Vit. D treatment
Both fluoxetine and light therapy are 67% effective in treatment of SAD using direct head-to-head trials. Light therapy was faster (improvement begins in one week). Compliance better with pills.
Melatonin to regulate circadian rhythm – avoid high doses in kids.
Exercise
DHA – essential fatty acid obtained in fish oil
I tell patients to get light boxes on eBay – other brands: Verilux, NatureBright Sun Touch, Northern Light Technologies
Note: Tanning beds are not light therapy