Depression has a dramatic effect on quality of life because it results in a persistent low mood that is accompanied by a low self-esteem and a loss of interest in things that give pleasure.
Elske de Haas, Ph.D. studied the effects of fearfulness on the chickens' own behavior and physiology, but also what it did to other individuals.
Fear is something we all know. It changes our behavior: we freeze, try to escape, or respond with aggression. Fear can also cause anxiety, which is a more complex phenomenon.
Anxiety. It is nature’s way to keep us out of harm’s way, so it is a useful emotion. At times, though, it can also be overwhelming. For some, it gets out of control, irrational, and even disabling.
The most common psychiatric disorders are mood and anxiety related. However, the underlying mechanisms of these diseases are still largely unknown. This complicates the development of effective treatment and drugs.