SAD

Question 1

Seasonal Affective Disorder.

Answer 1

Example of disorder mostly discovered, diagnosed and treated outside of medical profession & without prescriptions- not much about it in the research literature.

Winter depression/blues, linked with treatment with Bright Light Therapy- given in mornings.
-increased incidence of depressive symptoms/major depressive disorder during winter months.

Question 2

Symptoms

Answer 2

fatigue, reduction motivation, excessive sleeping (hypersomnia), increased appetite (carbs), weight gain, irritable mood, reduced sociability. Sometimes Mania in summer.

Question 3

Main theory

Answer 3

ppl with SAD are unable to adapt to shorter photo-period in winter.

Question 4

Pathology

Answer 4

lack of early morning light in winter.

• humans evolved in Africa- +/- 30 degree= similar day length in summer & winter.
• above or below= shorten at times of year.
• reduced intensity of light/cloudy weather.

Question 5

Epidemiology-

Answer 5

prevalence 0-10% with increasing latitude.

• more common in F, esp in childbearing years.
• acclimatization occurs in individuals who move to more extreme latitudes, SAD worse in recent migrants.

Longer-term adaption- (by natural selection) of populations who have been at extreme latitude for many generations (e.g. Iceland). - lower SAD prevalence than expected.
-this implies some genetic element- resistant prob resistant.

Question 6

Treatment

Answer 6

-Acclimatization- proportion ppl get better with time 1/3.

Light Therapy- seem be very effective, although it is hard to compare with placebo.
-indoor lighting 100-400 lux,
outdoor cloudy winter day 4000 lux,
bright sun 40,000 lux plus.
-treatment with “light boxes” before sunrise. admin in morning 10,000 lux for 30 mins for severe SAD.
-“light visor” close proximity of light source.

-issues funding tirals as not drug treatment= less money.