What about anti-depressants?
The most commonly prescribed type of anti-depressant now prescribed is the SSRI, which stands for Selective Serotonin Reuptake Inhibitor, an example of which is Prozac. These work on the levels of serotonin, a brain chemical which controls arousal levels, feelings of wellbeing, sleep and pain perception. They also, as do all anti-depressants, decrease the amount of REM sleep you get which, as you will learn from the Depression Learning Path, is essential to lifting depression. (However, there are much quicker ways of doing it than with drugs.)
During depression levels of serotonin drop as a result of over-arousal from negative introspection and lack of participation in pleasure-giving activity.
However, if after a course of anti-depressants, the person then goes back to negatively interpreting their life and what happens to them then it is likely that at some stage depression will return (although the relief from suffering is of course welcome).
Most anti-depressants, if they are going to work for a particular individual, will begin to work within three weeks of starting to take them. Side effects vary from drug to drug but may include drowsiness, anxiety, and sexual dysfunction as well as insomnia.
Contrary to the impression given by some advertising, no single anti-depressant has ever been shown to be more effective than any other in lifting depression.
The Depression Learning Path contains a comprehensive review of anti-depressants and their effectiveness.