Seasonal Affective Disorder and Fibromyalgia Syndrome

Nearly everybody finds that their mood changes with the seasons, but these changes are much more extreme for people with seasonal affective disorder (winter blues or winter depression – also aptly known as SAD). People with seasonal affective disorder find that their moods can alter severely as the days get shorter, particularly becoming depressed and low during the autumn and winter. Some people have the less common reverse seasonal affective disorder (summer depression or summer seasonal affective disorder [SSAD]), which occurs during the summer rather than the winter.

Symptoms of Seasonal Affective Disorder

Seasonal affective disorder symptoms include depression, anxiety, irritability and crying, social withdrawal, a craving for starchy and sweet foods, overeating and weight gain, oversleeping or insomnia, problems with concentration, aches, loss of libido, decreased activity levels, tiredness and a lack of energy. People with reverse seasonal affective disorder may find it hard to cope with high temperatures.

Causes of Seasonal Affective Disorder

The cause of seasonal affective disorder isn’t clear, but one theory is that it is caused by disruptions in melatonin, a hormone produced by the pineal gland in the brain. The production of melatonin is controlled by light – more is produced at night than during the day. Melatonin helps sleep and keeps the body to its 24-hour rhythm, and disrupted levels of melatonin can cause problems with sleeping. Another theory is that seasonal affective disorder is linked with a lack of serotonin, which is the precursor to melatonin.

Seasonal Affective Disorder and Fibromyalgia Syndrome

Up to 50% of people with fibromyalgia syndrome also report symptoms of seasonal affective disorder. According to a study carried out in Sweden, people with fibromyalgia syndrome tend to produce lower levels of melatonin at night, which may explain the problems with sleep at night and the tiredness during the day, as well as the increased rate of seasonal affective disorder.

The symptoms of seasonal affective disorder, especially the anxiety, depression and tiredness, can make it harder for people with fibromyalgia syndrome to cope with their muscle pain.

Treatment of Seasonal Affective Disorder

Getting out into daylight, especially when it’s sunny, can help, as keeping the house well lit with full-spectrum light bulbs, which produce light equivalent to daylight. Daily treatments of 30 to 60 minutes exposure to the very bright light (around 25 times brighter than normal household lights) produced by specially designed light boxes can also be used to treat seasonal affective disorder.

Some people have reported that light therapy also helps fibromyalgia syndrome symptoms, including fatigue, sleep and pain, but this has not been supported in clinical trials.

Exercise, especially outdoors, is a good idea for people with seasonal affective disorder, both because of the increased exposure to daylight and the natural mood lift that exercise brings. People with fibromyalgia syndrome can also find that exercise helps with the pain and tiredness and promotes sleep (see ‘Exercise and Fibromyalgia Syndrome’). Eating food rich in omega-3 fatty acids, including fish, helps seasonal affective disorder in some people. Antidepressant treatments, especially selective serotonin reuptake inhibitors such as Prozac (fluoxetine), may also be helpful.