Evolutionary Approaches To Depression - Possibilities of Depression As A Dysregulated Adaptation

Possibilities of Depression As A Dysregulated Adaptation

Depression, especially in the modern context, may not necessarily be adaptive. The ability to feel pain and experience depression, are adaptive defense mechanisms, but when they are “too easily triggered, too intense, or long lasting,” they can become “dysregulated.” In such a case, defense mechanisms, too, can become diseases, such as “chronic pain or dehydration from diarrhea.” Depression, which may be a similar kind of defense mechanism, may have become dysregulated as well.

Thus, unlike other evolutionary theories this one sees depression as an maladaptive extreme of something that is beneficial in smaller amounts. In particular, one theory focuses on the personality trait neuroticism. Low amounts of neuroticism may increase a person's fitness through various processes, but too much may reduce fitness by, for example, recurring depressions. Thus, evolution will select for an optimal amount and most people will have neuroticism near this amount. However, genetic variation continually occurs, and some people will have high neuroticism which increases the risk of depressions.