SAD

It is that time of year again when the cold weather reminds us that the change of season is upon us. It has prompted me to reassess my winter wardrobe (which is sadly lacking) and I am finding it just that bit harder to get out of bed in the morning. But then again I have children who take care of that. My mood has altered somewhat and I also find myself hoping that we will be blessed with just a few more lovely sunny days.....

As I understand it, all these feelings are normal. For some people however, there is a very real winter related disorder called Seasonal Affective Disorder or SAD for short. It is also commonly confused with the winter blues or winter depression but the two are in fact different. There has been much written on this topic since it was first defined in an article published in a Psychiatry paper in the early eighties.

The American Psychiatric Association recognizes SAD as a sub type of a major depressive disorder.

Symptoms of SAD include lack of energy, difficulty getting up in the mornings, overeating, craving carbohydrates (and weight gain), difficulty concentrating and completing tasks, withdrawal from usual social activities and friends/family. Of course this leads to depression. Symptoms typically begin in autumn, peak in winter and usually disappear in spring and summer. These people are known to experience normal mental health throughout the rest of the year.

There are four major criteria as set out by the American Psychiatric association DSM -IV which must be met in order to diagnose SAD:

Depressive episodes at a particular time of year

Remissions or mania/hypomania also at characteristic time of year

These patterns must have lasted two years with no nonseasonal major depressive episodes during that same period and

These seasonal depressive episodes outnumber other depressive episodes throughout the patient’s lifetime.

Winter blues is considered to be much more mild than SAD. Symptoms still include feeling sad and a lack of energy but the key difference is that these people can still function. People diagnosed with SAD, typically find it difficult to perform normal activities of daily living.

Apparently many more women are affected by SAD than men. While it is far more common in the Northern Hemisphere than Australia, it has been estimated that one in three hundred Australians are affected.

It is also worth noting that there are a small number of people who display depressive symptoms such as insomnia, decreased appetite, weight loss, irritability, anxiety, and decreased sex drive in the SPRING and SUMMER months (Summer SAD). These people may also have short bouts of mania/hypomania behaviour at this time of year.

Classic major depression often (but not always) presents with decreased appetite (weight loss) and decreased sleep patterns.

Research shows that it is the lack of light during the winter months which leads to SAD. The brain does not produce enough serotonin which has been found to lead to depression. Serotonin is a neurotransmitter which is produced by the brain and relays messages from one part of the brain to other parts. It has a major influence on mood, and our serotonin levels are lowest in winter. Put simply, serotonin stimulates us during the day time but it is another hormone, melatonin whose job it is to promote sleep.

In the evening the body (or more accurately the pineal gland) responds to decreased light by making melatonin. Usually the secretion of melatonin peaks in the middle of the night when we are in our deepest sleep but is switched off by the pineal gland in response to light exposure in the mornings.

During winter, people affected by SAD commonly have higher levels of melatonin during the day which leads to many of the previously discussed symptoms associated with SAD. The body’s internal body clock is out of “synch”.

Light therapy, either bright white light/blue light has been used to effectively treat SAD by suppressing melatonin and stimulating serotonin production. It helps to reset the body’s natural sleep/wake cycle. Other treatments such as taking melatonin or other antidepressants used in conjunction with light therapy have proven to be effective. Or one could just head outside for a natural dose of light – great in the summer months but harder to use effectively in the colder winter months.

During my research I was also surprised to learn that it has been estimated that up to 20% of people with SAD already have/ go on to develop bipolar disorder. Interestingly, some studies have indicated that people with dark coloured eyes react differently to light than those with light coloured eyes. Also that genetic differences in photoreceptors and glucose metabolism also play a role.

Lisa