An Evolutionary Perspective on Anxiety and Anxiety Disorders

Anxiety and depression are two of the negative emotions described by Levenson (1994). These emotions, along with anger, tend to disrupt the emotional homeostasis of the body, while the positive emotions such as contentment tend to restore homeostasis. The actions of anxiety and depression may be synergistic but they differ in important respects. Anxiety usually has an obvious cause and also a goal (safety, and the avoidance of danger), whereas depression usually has no obvious cause and also has no goal. Depression is thought to be related to social factors in relation to other human beings, whereas anxiety is related partly to social situations but also to non-social dangers. The strategies for dealing with human danger include submission, whereas this is not an appropriate response to non-human dan‐ ger. Anxiety is classically thought to be concerned with the threat of danger, whereas de‐ pression is thought to be the result of danger. I will describe later how the negative emotions can be divided into the escalating emotions such as anger and the de-escalating emotions of anxiety and depression