Seasonal Affective Disorder

The discovery of light's ability to suppress the production of melatonin gave rise to a wealth of research throughout the 1980's, particularly amongst doctors and scientists looking at the cycle of depression, and other problems, associated with changes in the seasons of the year.

This research into what became known as Seasonal Affective Disorder (SAD) also prompted widespread public interest, leading to a number of best-selling books on the subject and a cottage industry of people making light boxes.

Most of us feel a bit 'down' from time to time during the short dark days of winter. You don't seem to have a lot of energy, you find it difficult to get up in the morning and you start putting on a few pounds.

Well, in the case of SAD suffers, they feel exactly the same way – except that their symptoms are magnified to the point at which they feel permanently depressed and tired.

They simply feel unable to cope with the trials and tribulations or everyday life and want to withdraw from the world.

In extreme case of SAD, sufferers' appetites become much increased and they gain a substantial amount of weight. In addition, they will often sleep more, sometimes adding as much as three or four hours to their sleep.

I should point out that SAD sufferers experience the same symptoms that many of us suffer during the winter period – they simply suffer them to a much greater degree. If you find yourself putting on a bit of weight, feeling a little depressed and sleeping a bit more, it doesn't mean that you suffer from SAD.

The key to SAD lies in the change in length between day and night during the winter months which, as the days shorten and the nights lengthen, confuses your internal body clock. As darkness falls earlier and earlier in the day your body clock starts to re-adjust and tells your brain that it's time to sleep. Similarly, as the light appears later and later in the morning, your body clock responds by telling your brain that it's not time to get up yet.

Now we don't want to get too far off track here with a discussion about SAD. After all, this book is about finding solutions to your sleeping problems and SAD falls somewhat outside of this subject area.

In relation to the use of light therapy to assist in overcoming insomnia, however, research into SAD, and in particular the changes to your internal body clock, represent the key to the use of bright light therapy to assist in the cure of insomnia.