To solve our problems, we must devote time to analyzing them, and in order to devote the appropriate amount of time, there should be minimal disruption of the problem-solving process. Depressive rumination, or the process of devoting significant cognitive effort to analyzing depression-triggering problems, is a time consuming process that has negative consequences on biological fitness by drawing attention away from sex, food, and social interactions. However, Andrews and Thomson observed in their experiment comparing accuracy on cognitive laboratory tasks that depressed people tended to outperform the non-depressed people in certain cognitive exercises. Statistically, in the results of the experiment, lower moods positively correlated with higher intelligence scores. From this study, it was apparent to Andrews and Thomson that depressive rumination facilitates the problem-solving process by sustaining the mind’s analysis of the problem, and by minimizing any disruption in the process. Furthermore, according to recent studies, the ability to execute depressive rumination is rooted in the biology of the brain.
The ability to focus with high intensity is controlled by the left ventrolateral prefrontal cortex (VLPFC). Several studies have found that in depressed people, activity of the VLPFC is much higher than in non-depressed people, with the neurons in the VLPFC firing continuously in order to keep maximum attention focused on complex problems. Andrews and Thomson interpret this high activity in the VLPFC as the biological basis of depressive rumination, enabling people to stay focused on their predicaments. Moreover, they explain that the sadness that follows depressive rumination is part of a coordinated system with the activation of the VLPFC. From these studies, it seems that if depression did not exist, perhaps humans would not be as well equipped to solve complex dilemmas.
Andrews and Thomson’s analytical rumination hypothesis has three facets: first, that depression is provoked by analytically difficult problems that impact biological-fitness related goals; second, that depression systematizes the body to promote persistent analysis of the triggering problem, an act known as depressive rumination; and third, that to solve these difficult problems, depression makes tradeoffs with other goals to spur analysis of the triggering problem. According to epidemiological evidence, the ‘triggering problem’ that initiates depression is usually an avoidable stressor rather unavoidable, and depressed people tend to apply significant cognitive strain to understand how the stressor could have been avoided.
Now the question arises: what triggered the evolution of depression in humans? To this, Andrews and Thomson have no clear answer; however, they have logical theories. Throughout the course of human evolution, humans are believed to have lived in groups. Living in groups is a beneficial practice in terms of biological fitness because of the benefits of sharing food, protection from predators, raising children, and close proximity to mates. However, introducing a social aspect into human interactions requires that humans develop the ability to cooperate with one another as well. Therefore, humans that had the ability to solve the complex social dilemmas that their fitness depended on (while still effectively competing for resources and mates) were the ones that were repeatedly selected over evolutionary time. Therefore, the development of emotions and problem-solving processes can be thought of as adaptations that gradually accumulated, giving humans the best chance for survival and reproduction. Additionally, Andrews and Thomson believe depressed individuals were also able to elicit sympathy and support from group members, an advantageous trait when conflict arose against other individuals.
Another theory that Andrews and Thomson propose is that depressive rumination is the optimum analytical tool that natural selection could produce to prevent the recurrence of suffering from avoidable stressors. For example, in the alternative problem-solving process of operant conditioning, organisms learn to avoid certain negative outcomes by associating those outcomes with environmental stimuli and using that information to avoid the causes of the detrimental outcomes. However, multiple exposures to the negative outcomes required by operant conditioning are risky if those outcomes are deadly. Therefore, it is likely that natural selection favored the more complex way of thinking (depressive rumination) that enabled humans to foresee avoidable stressors, allowing them to take the appropriate preventative measures.
Depressive rumination is a process that serves as a beneficial adaptation because it allows people to solve the problems that trigger depression in an effective way. Although depression comes with its trade-offs of low mood and sexual disinterest, the benefit of depressive rumination serves the higher goal of solving complex social dilemmas which impact biological fitness. Although no concrete evidence has proven the evolutionary basis behind the prevalence of depression, Dr. Andrews and Dr. Thomson’s work provides a stepping-stone for future research in the science of behavioral evolution.
Iyza Baig
Word Count: 934
Andrews, Paul W., and
J. Anderson Thomson. "The Bright Side of Being Blue: Depression as an
Adaptation for Analyzing Complex Problems." Psychological Review 116.3
(2009): 620-54. American Psychological Association. Web. 13 Feb.
2013. <http://psycnet.apa.org/journals/rev/116/3/620.pdf>.
Lehrer, John.
"Depression’s Upside: Is There an Evolutionary Purpose to Feeling Really
Sad?" The New York Times. The New York Times, 25 Feb. 2010. Web.
13 Feb. 2013.
<http://www.nytimes.com/2010/02/28/magazine/28depression-t.html>.
Well, this is certainly good news! Kind of... the article implies that depressive rumination leads to increased productivity. However, in the contemporary understanding of depression, individuals who are depressed exhibit symptom of apathy and despondence, which tends to add to one's problems rather than solve them.
ReplyDeleteReading about depression from an evolutionary and neuroscientific view was quite more thought-provoking than the ordinary psychological standpoint! It seems to make sense that depression is a method of solving social problems because many depressed people do hope for better futures. Do you think that depression occurs in other species and for similar reasons? I used to own a rabbit that seemed to suffered from depression because when we gave her more love and attention, her mental health improved!
ReplyDeleteGreat point, San-Pei! I didn't even think about how depression could have an effect on animals. I'm sure it would be difficult to explore that topic though since animals can't provide us insight into their thought processes. I wonder if examining their behavior alone would provide us enough data to explore the effect depression has on them.
DeleteIt is interesting to see how evolution often presents both costs and benefits to the evolution of certain traits. While the benefits of depression are rarely spoken for, it is cool to see that there are some. I wonder if there is a correlation between intelligence and depression.
ReplyDelete-Jesse Passman
This post was interesting to read after the post about schizophrenia because both demonstrate how much we overlook mental health issues and why the exist. There is often such a negative stigma surrounding mental health, and to show that there are actually positive points associated with the disorder could be useful in therapies. It amazes me to see how resilient the body and mind can be, and how there is often a purpose behind diseases and disorders.
ReplyDeleteDepressive rumination allows one to think about solving a problem, which is productive, but what would happen if a solution was not found? Would this lead to further depression and potentially suicidal thoughts? As with many things, it seems that moderation is key in terms of depressive rumination. When treating depression, could one course of action be trying to determine the problems one faces in life and addressing them in addition to treating the symptoms using drugs that affect neurotransmitters?
ReplyDeleteGreat point Sarah! I also wonder what the extent to which an individual's depression can be favorable, and at which point it can become disadvantageous.
DeleteIt is interesting to think of depression as being selected for its advantages in complex problem-solving; I examined in my post (in The Evolution of Emotions) a perspective that suggested that emotional disorders should be viewed in terms of the evolutionary advantages of the "normal" emotions they correspond with (for depression, this would be sadness). Instead of viewing depression as simply an over-expression of sadness, however, it seems equally useful to consider the evolutionary advantages it could present - and to incorporate this into the development of treatments.
ReplyDelete-Fatima Alvi
Wow I had no idea there was any helpful aspect of depression. I think possiblly focusing more on this could reduce stigma about depression and help those who have depression view it a little differently.
ReplyDeleteI agree depressive rumination is good for problem-solving. However, I believe it's a concern if the period of depressive rumination is prolonged due to an individual being unable to solve his/her problems.
ReplyDelete