Daylight Bulbs

What is seasonal affective disorder (SAD)?

Seasonal affective disorder (SAD), also known as winter depression affects around two million British citizens each year. Symptoms are more common in people aged 18-30 years. We think two times more women than men are affected, but this could be explained by the fact that men are less likely to admit to being depressed.

People usually experience no mental health problems in most of the year, but tend to develop depressive symptoms during the winter months. Often the symptoms appear in patients between September and April each year with symptoms to their lowest in December, January and February.

Symptoms of SAD

The symptoms of SAD varies between different people. A small percentage of SAD sufferers are struggling to cope during the winter without continuous treatment. However, for the majority of SAD sufferers, symptoms tend to be less intense and last for short periods of time.

The common symptoms of SAD (many of which are related to the general depression) include:

• General Depression - feeling glooming
• Mood Swings
• Social withdrawal - not wanting to see people
• Anxiety - inability to cope
• Lethargy / fatigue - no energy for everyday tasks
• Sleep disturbances - sleeping too much and not wanting to get out of bed
• Overeating - carbohydrate cravings, which causes weight gain
• Frequent illness - thanks to a weakened immune system
• Difficulty concentrating or making decisions
• Loss of libido

What causes SAD

The exact cause of SAD is still unknown. However, most theories center on the deficiencies identified during the winter months because of reduced hours of daylight and lack of sunshine.

Light can trigger messages part of the brain called the hypothalamus, which helps control mood, sleep and appetite. A lack of exposure to light and problems with certain chemicals in the brain is thought to prevent the hypothalamus from working properly.

It is common for SAD sufferers have low levels of a brain chemical called serotonin. Serotonin helps to transmit messages from nerve cells in the brain and plays a role in "lifting the state of mind. It is believed that the development of serotonin is affected by exposure to sunlight and thus a lack of exposure to sunlight means that less serotonin is produced.

SAD sufferers are likely to respond to a dimming of lights producing more of a chemical called melatonin during the winter than non SAD sufferers. Melatonin helps to slow the biological clock affects sleep patterns and mood changes. When patients are treated with intense light, their melatonin levels tend to return to normal. However, the use of light therapy to affect melatonin levels will not completely cure SAD.

The diagnosis of SAD

A GP will be able to advise you if these symptoms are caused by SAD. SAD is difficult to diagnose because the symptoms are very similar to those of other types of depression and other mental health problems.

An appearance of the symptoms listed above does not automatically mean that you SAD.

Diagnosis will usually take place when symptoms were experienced during the same period (usually winter), followed by symptoms of compensation within a month (spring), over a period of two or more consecutive years.

Treatment for SAD

Recent research has shown that SAD sufferers responded dramatically to the "light therapy". By exposing SAD sufferers t.