How antidepressants work. PART 3

Here is the last part of the material about Antidepressants and it is actually about them. After 2 long and sweet parts of a preface here is the last one which describes depression build-up process.

"5. Depression

People with depression usually have problems with poor sleep, low mood and appetite, loss of energy and interest or pleasure etc. It is a common illness, affecting 3% of the population per year. The main theory about why this happens is the so-called "monoamine hypothesis".

We know that serotonin and noradrenaline in the brain are involved with control of sleep/wake, emotions, mood, arousal, emotion, drive, temperature regulation, feeding etc. Thus, if a person has too little serotonin and noradrenaline in the part of the brain that controls mood, this will produce too little activity, and that part of the brain become slower and less effective. This will lower mood.

In depression, it is known that there are reduced levels of serotonin and noradrenaline. These reduced levels lead to a lowering of mood. The full reasons are not fully known but stress may well play a part in causing this.

"Normal" communication between cells:

"Reduced" nerve activity e.g. as in depression:

There are lots of other theories about how depression occurs e.g. genetics, how the brain develops, stress etc. There may in fact be many causes and in each person there may be a combination of these. Stress may in fact cause changes in the brain which then result in reduced levels of serotonin and noradrenaline. Transmitters other than much serotonin and noradrenaline are probably also involved.