Nesse’s article, “Is Depression an Adaptation?”, suggests that “low mood” and depression may have the adaptive function of decreasing motivation in situations in which the likelihood of a successful outcome is low or when pursuing further action could be potentially dangerous. This hypothesis seems somewhat problematic, especially applied to depression.
According to this article, “low mood” is within the range of normal experience, and it seems likely that it decreases motivation to pursue unreachable goals. But how do we define depression? Sure, the DSM-V has a definition of depression for us, but that definition is based on arbitrary criteria (number/duration/frequency of symptoms) that change with every new edition of the manual. How, then, could someone claim that depression is an adaptation if there isn’t even a clear, objective way to define it? Maybe I’m being overly critical here, but branding depression as an adaption could have serious implications in terms of the way in which people who suffer from clinical depression are treated and/or perceive their condition.
Those who suffer from severe depression don’t only have their mental health to worry about. Depression can also have grave physical health consequences. On top of that, there are thousands of depression-related suicides each year (although the number of suicides is low in comparison to the the total number of people who suffer from depression). However, the adverse health effects of depression and, especially, the incidence of suicide do not make sense from an adaptive perspective, because both of these things could result in a reduction in fitness.
To conclude, low mood is quite possibly an adaptation that allows us to give up on pursuits that could have negative costs to us in the future, but depression, a prolonged and intensified version of that low mood, is potentially maladaptive. We should be careful not to conflate the two.
I agree that an incompletely defined state of depression should not be hastily concluded as an adaption. You make an excellent point that the various specifications provided in the multiple editions of the "Diagnostic and Statistical Manual of Mental Disorders" are not concrete.
ReplyDeleteIn my opinion, the DSM's method for defining depression does not work well for a generalized public. Depression seems to me as a subjective ailment, meaning that the specifics, like frequency and duration, all vary from person to person. As such, diagnosing people with depression based on data from all people instead of the individual can lead to many false positives and false negatives. If I am correct in saying that the DSM uses statistics to define depression, then that explains why their definition changes for all new editions, as new data may have different results than old data.
On the other hand, Nesse uses the term, depression, to mean “severe states of negative affect that are often but not necessarily pathological.” (Nesse, 15) His usage of the word differs from that of the DSM’s usage in that his definition is more encompassing and I think that when Nesse’s definition of depression is used, depression can be concluded as an adaption, because now we have a more concrete description of depression to use.
Depression seems to be a more potent form of low mood. It could be that depression was an adaptive trait that kicked in when low mood was not an intense enough trait to stop wasted energy on unachievable goals. As support, Nesse remarks that “clinicians have long noted that depression is common in people who are pursuing unreachable goals.” (Nesse, 16) Nesse also makes mention of Klinger’s incentive-disengagement theory on page 16. Basically, Klinger’s theory is that there are states of motivation that individuals go through that eventually lead to the accomplishment of the goal, or giving up and not wasting any more energy on achieving the goal. Depression serves a role of disengaging individuals if low mood does not suffice.
I agree with the idea that how we define depression is ever changing with no good way to define it and I also agree that the way we characterize depression affects those who have it, by way of how society treats them. However, I don’t agree with the idea that low mood, but not depression may decrease motivation in situations in which the likelihood of a successful outcome is low or when pursuing further action could be potentially dangerous.
ReplyDeleteLet me first start off with the things that I agree with you on. How we characterize depression effects how society treats people with depression. Depression is not an easy thing to define because it has so many forms of variation in it. No two forms of depression are the same. Much of society tiptoes around people who have depression because they don’t want them to go off or become more depressed. If we were to “brand” depressed people as having an adaption as you said, I one hundred percent agree with you that it would have implications in society because even right now, if you are diagnosed with depression you have implications in society. This would open the gates for even more special treatment, which is not really something that depressed people want in their lives.
On the other hand, I have to disagree with you and agree with Nesse when you talk about how depression doesn’t cause us to give up on pursuits that could have negative costs to us in the future. I can definitely see your point, however growing up with a mom who had depression; I have a different point of view on this topic. Often times as a kid, my mom would not do things in which she thought she would fail. When you see the world through a depressed state of mind, you pretty much think that you are going to fail at anything you do. Sometimes she wouldn’t even drive me places because she believed that with her luck, we would get in a car crash and something bad would happen. I think that low mood is a sub category of depression and the two go hand in hand. Therefore, while I see where you are coming from, I think that both low mood and depression may decrease motivation in situations in which the likelihood of a successful outcome is low or when pursuing further action could be potentially dangerous.