Less daylight during the fall and winter causes depression in some people.

Other factors contributing to seasonal affective disorder (SAD) may include genetics and age. We know that neurochemicals are involved in the regulation of our mood and functioning.

Melatonin is a hormone that our brains produce during the hours of darkness. It is involved with regulation of sleep, body temperature and release of hormones. As with any hormone, the amount produced is important.

People with SAD produce too much melatonin. This disrupts our internal body clock leading to depressive symptoms. If you have had episodes of depression that clearly have an onset in fall or winter followed by remission of symptoms in the spring or summer, you may have SAD.

Symptoms of winter-onset seasonal affective disorder include:

• Depressed mood
• Irritability
• Hopelessness
• Anxiety
• Loss of energy
• Social withdrawal
• Oversleeping (feeling like you want to hibernate)
• Loss of interest in activities you normally enjoy
• Appetite changes, especially a craving for foods high in carbohydrates such as pastas, rice, bread and cereal
• Weight gain
• Difficulty concentrating and processing information

Medications or light therapy (phototherapy) can be used to treat SAD. The type of light used, distance from the light, and amount of time, are very specific. The light should be of adequate intensity, 10,000 lux (lux is a measurement of light intensity). At 10,000 lux, the amount of time required in front of the light is 30 minutes.

If the light is 5,000 lux, then the amount of time will be 60 minutes. You need to have your eyes open, so that the light can reach the retina in the back of your eye. You do not have to look directly at the light. You can read, knit, etc. The light purchased should have information on exactly how to use the light effectively. The distance you sit from the light will range from about 12-18 inches. The light will not emit damaging UV rays.

Speak with your health care provider if you think you may have SAD. Treatment is available. There are possible side effects, such as eye strain and headaches. Typically, light therapy is done in the morning, as it can cause insomnia if done too late in the day. If you struggle with bipolar, a hypomanic or manic episode can be triggered by light therapy, so should be used with extreme caution.

You can purchase a phototherapy light without a prescription, but speak with your provider first. Treat SAD, so you can enjoy this beautiful time of year!