Seasonal Affective Disorder and Light Therapy

Human beings have a natural reaction to the changing season. During the winter we are all used to the shortened hours of daylight and most people find that at this time of year they sleep and eat slightly more. Though none of us may welcome the dark mornings and short days, for some people this time of year can cause considerable distress. These people are suffering from SAD; seasonal affective disorder.

Symptoms of Seasonal Affective Disorder

SAD affects people in a range of ways. Most people experience the following symptoms:

• Oversleeping, though still feeling fatigued.
• Reluctance to get out of bed, often needing to take a nap during the day.
• Feelings of depression, anxiety, despair and guilt, normal daily routine may become difficult and frustrating.
• Feelings of extreme lethargy, reluctance to participate in daily activities.
• Problems interacting with family members, loss of feelings or libido.
• Overeating due to constant cravings for food.
• Physical symptoms such as joint pain or stomach cramps, often a lowered immune system.

SAD is not a psychosomatic or imaginary illness, for sufferers, it is only too real. These symptoms tend to start around September and can carry on through to April, though they tend to be worse during the winter months.

What Causes Seasonal Affective Disorder?

Research has shown that the problem stems from lack of bright light in winter. Light makes a significant difference to the functioning of brain chemistry although the exact means of effect are still unknown. It is known that the nerve centres in our brain which control our daily functions are affected by the amount of light entering the eyes. During the night the pineal gland produces a chemical called melatonin, which is responsible for making us feel drowsy. The morning light indicates to our brains that it is time to stop producing melatonin and we usually start to feel more awake. However, on door days or when light is poor indoors there may not be enough of it to trigger this effect.

Therapy for Seasonal Affective Disorder

One form of treatment, which has been shown to be effective, is bright light therapy. The recommended amount of light is equivalent to that of a clear, spring morning (this is five times brighter than a normal well lit office). For many people sitting in front of a light box for between ¼ to ¾ of an hour each day is very effective at alleviating symptoms. Bright light therapy does not entail the user looking at the light, sitting in front of it and reading or watching TV is sufficient to allow enough light to reach the eyes. At least 2500lux (lux being the special measure of brightness) is needed to be affective. Changing the light bulbs in your house to 'full spectrum' daylight bulbs will not have the same effect.

The rhythm of melatonin levels is maintained by regular daily routines. It is important to keep you mealtimes as regular as possible to keep your body in sync. Keeping your diet light at night can also benefit melatonin production. This is because after nightfall when melatonin is triggered, the digestive process is slowed. Any heavy meals eaten at bedtime can cause digestive problems and disrupt the quality of sleep. Stimulants such as coffee, tea and colas can also interfere with melatonin production and should be eliminated as much as possible. It is also best to avoid any vigorous activity late at night. Morning exercise out of doors, if possible, would be most beneficial.

Melatonin supplements are available. They should be taken two hours or less before bedtime in order to release the hormone at the same time that natural production peaks. You should not feel groggy after melatonin-assisted sleep but refreshed and alert.