Year after year, when winter rolls around, some people may repeatedly experience a significant change in the way they feel and behave. Starting in late fall and subsiding in early spring, they may feel especially sad, irritable, or sluggish, want to sleep more, and crave sweets and starchy foods. They might notice a lack of interest or pleasure in usual hobbies or friends, or a decreased interest in sex. These are all possible signs of Seasonal Affect Disorder (SAD), a type of depression experienced by an estimated 10% of people living in northern countries. If you are wondering whether you have SAD, take this short quiz: http://www.msnbc.com/modules/SeasonalAffectiveness/default.asp Causes of SAD: SAD is thought to be caused in part by genetic factors (it can run in families), as well as by the chemical changes that occur with reduced sunlight. Reduced sunlight can cause changes in one’s circadian rhythm, the body’s “internal clock.” It can also affect the body’s production of melatonin (a sleep hormone), as well as serotonin (a chemical in the body that helps regulate mood). When these systems become disrupted, depression can result. What to do: One way to correct this disruption is to increase the amount of light you are exposed to during the winter months. Take advantage of those sunny winter days by bundling up and spending time outdoors when you can. When indoors, spend as much time as possible in the sunnier areas of your home or workplace. If this is not adequate or possible, another option is to purchase a special type of light bulb that mimics outdoor light. Some examples of these “light therapy” products can be found at the following website: http://www.northernlighttechnologies.com/splash.php. It is recommended that you consult with a mental health professional prior to beginning light therapy, as well as if your depression feels severe and/or does not go away.