|"Sunset Winter" (2007) by Jonathan Hendrick|
Seasonal Affective Disorder (SAD) is a kind of depression that ebbs and flows based on the changing of seasons. One of SAD's key symptoms is insomnia, which starts out mildly during the transition between fall and winter and which gradually worsens with the further darkening of the days.
(Interestingly, there are some people who suffer SAD only during the brighter spring and summer months.)
The changes in light that come with darker days and longer nights can negatively affect both mood and sleep patterns thanks to impacts on circadian rhythms, which align with the Earth's light and dark cycles.
The reduction in light can also alter emotional chemistry; lower light levels can lead to reduced levels of serotonin, a neurotransmitter which affects mood, resulting in depression. Another neurotransmitter, melatonin, is manufactured by the brain and this process may kick in well before one's typical bedtime as the nights grow longer, which can lead to adjustments in sleep habits that can be disruptive until the transition is complete.
Other symptoms typical to SAD include:
- Appetite changes
- Low energy
- Problems focusing
- Relationship problems
- Sleeping too much
- Suicidal thoughts
- Weight changes
If you have sudden insomnia during the transition between the fall and winter, and you have any of these other symptoms, you are best advised to see a doctor to determine if you actually have SAD instead of insomnia. Your doctor will likely ask a lot of questions and run some tests to make sure your symptoms are actually related to SAD. You could also have chronic insomnia, defined as sleepless nights that recur at least 3 times a week and over a span of 3 or more months.
Keep in mind that insomnia can also be a sign of other problems, including drug interactions or other health conditions you may not be aware you have. Don't presume that because you have some of the symptoms above that you have SAD; let your doctor help you figure that out so you can treat your issues appropriately.
Science on the Subject:
- Depression and Sleep (National Sleep Foundation)
- The role of beliefs and attitudes about sleep in seasonal and nonseasonal mood disorder, and nondepressed controls (Journal of Affective Disorders) [ABSTRACT]
- Seasonal Affective Disorder: A Review of the Syndrome and Its Public Health Implications (Biology Online) [ABSTRACT]
- Sleep and Depression. (Journal of Clinical Psychology) [ABSTRACT]
- Sleep in fall/winter seasonal affective disorder: effects of light and changing seasons (Journal of Psychosomatic Research) [ABSTRACT]