This is a mood disorder that causes endless feelings of sadness and loss of interest in any kind of activity. This disorder affects how you relate to everything around you and at the end of it all you will fail to attend to your normal duties as it causes emotional and physical problems, it will control your thoughts and your behavior. It&rsquo's accompanied by a feeling of worthlessness and this explains why most people who commit suicide do so because of depression. Contrary to what people think depression is more than just a feeling of "lows" that you can easily escape from. It requires long-term treatment to be fought effectively.