How to buy a SAD light Seasonal affective disorder treatments

Seasonal Affective Disorder (SAD) is a severe depression experienced during the winter months.

It has been reported in some people to start between the ages of 20 and 30 but it can develop at any age and affects at least twice as many women as men. 

Many more people suffer from the 'winter blues' - a less severe form of the condition and a normal response to gloomy winter days. 

Symptoms of SAD

Some sufferers report SAD as beginning when the clocks go back in October but may start before this.

The symptoms of SAD include: low mood; low self-esteem and confidence; a loss of pleasure in usual activities; marked lethargy; feelings of guilt; and social withdrawal. 

It may even lead to suicidal thoughts. Unlike sufferers from non-seasonal depression, people with SAD tend to sleep more rather than suffering from disturbed sleep. 

SAD sufferers may also crave carbohydrate-rich and sweet foods which can lead to an increase in weight.

Causes of SAD

The NHS states that the amount of sunlight you receive affects some of the chemicals and hormones in your brain but its not clear exactly what the effect of this is. 

One theory is that light stimulates a part of the brain called the hypothalamus, which controls mood, appetite and sleep. 

In people with SAD, lack of sunlight and a problem with certain brain chemicals prevents the hypothalamus working properly. 

The lack of light is thought to have three effects:

• It affects the production of the hormone melatonin
• It affects the production of the hormone serotonin
• It disturbs your circadian rhythm (the psychological process that regulates your body's internal clock)

People with SAD produce much higher-than-normal levels of melatonin in winter. This results in symptoms such as sleepiness and a lack of energy.

SAD sufferers usually have lower-than-average serotonin levels during the winter months which may be the cause of symptoms such as low mood.

Light therapy 

Light boxes are a form of light therapy used to treat SAD or regularly occurring episodes of depression during specific times of year.

Light therapy is a recognised therapy which logically replaces the sunshine you would see in summer. 

Bright light hits the retina at the back of the eye and sends nerve signals to parts of the brain, affecting chemical and hormone levels and improving mood.

Light therapy is thought to work by simulating the sunlight that is missing during the darker winter months.

The additional light encourages your brain to reduce the production of melatonin - the hormone that makes you sleepy - while increasing the production of serotonin - the hormone that affects your mood.

SAD lights

SAD lights are used to treat more severe seasonal depression. 

The light given out by a SAD light is like sunlight without the ultra-violet rays so it will not hurt the eyes or skin. 

Ordinary light bulbs are not strong enough. 

You will need to spend some time each day in front of the SAD light which exposes you to light almost ten times the intensity of lighting within the home.

The benefits continue as long as the lamp is used daily. 

But if you are experiencing symptoms before using the light you are less likely to see benefits and should probably start using it earlier the following winter. 

It should take one to two weeks for symptoms to lessen, but may only take a few days. 

Research into the efficacy of SAD lights is often on a small scale but there is evidence that SAD lights using both white and blue light are effective. Blue light produces a more intense beam.

Side effects are rare but could include mild headaches or dry or burning eyes and mucous membranes particularly in the first few days of use. 

You could try decreasing the time spent in front of the light or sit slightly further away or use a humidifier or artificial tears to combat dryness. 

Very bright light may not be suitable for those with an eye problem or eyes that are particularly sensitive to light. It may also be unsuitable for epilepsy sufferers or those on certain anti-depressants.

Dawn simulators

Dawn simulators are devices that slowly increase the light in the room over a period of up to 90 minutes just before you would normally wake up in the morning. 

Using one can help reset the daily body clock or Cicadian rhythms which can be disturbed by lack of sunlight causing disrupted sleeping and waking patterns.

The light intensity is not as high as a light box. 

And although they may be used in conjunction with a light box for treating symptoms, they are not a medical device and would not be used alone for treating the severe symptoms of SAD.

Self-help

The Royal College of Psychiatrists says that self-help can also be used to help the symptoms of SAD.

This includes going outside as much as possible during the winter and continuing any regular exercise, ideally outdoors. 

 If you work in an office you might try a daily walk in the park at lunch-time. 

This could give 3,000-4,000 lux even on a cloudy day and as much as 10,000 lux (what a SAD light generally emits) on a sunny summer morning. 

Even going to a window to absorb natural daylight can help.

You could also switch on more lamps, have ceiling lights put in, or use more standard lamps to increase brightness. 

A winter holiday in the sun may help, but unfortunately only for as long as you are away.

Other options

Alternatives include anti-depressants which may be helpful in severe SAD particularly if taken before symptoms emerge.

Or talking therapies such as cognitive behavioural therapy (CBT), or counselling or psychotherapy may help you cope with symptoms. 

If your symptoms are so bad that they are affecting normal life adversely, see your GP for medical help.