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Summary of:
Nesse, R. M. (2000). Is depression an adaptation? American Medical Association; Arch
Gen Psychiatry, 57, 14-20. Retrieved from http://wwwpersonal.umich.edu/~nesse/Articles/IsDepAdapt-ArchGenPsychiat-2000.pdf
Summary by Andy Earle, Connor Gill, Chris Schulz, and Simon Stewart
For Dr. Mills’ Psyc 452 class, Spring, 2014
Depression affects 10% of the US population in a year. It is very difficult to
differentiate between pathological and non-pathological depression, and patients
move back and forth between syndromal and subthreshold depression over time.
The researchers set out to figure out whether or not depression is an evolutionary
adaptation. Answering this question, though, entailed several things. First,
depression needed to be determined as a defect, defense, or a malformed defense
of an individual. Second, they declared that evolutionary hypotheses necessarily and
by nature must be formed in terms of their situational origins, rather than their
functional effectiveness. Finally, low mood (which is different from depression) must
be shaped to help motivate a change in negative situations and that the self-efficacy
of an individual in a given situation should have a greater effect on mood-related
reaction to life events than the events themselves.
A primary issue in the study of depression is that of fundamentally differing
views in defining depression. Some researchers view depression from a purely
pathological viewpoint; they see depression as a disease of the mind. Others see it
as a defense mechanism, and still others see it as a malformation or defect of a
defense mechanism. These different viewpoints lead to disagreements in
terminology. “Low mood” and “depression” are difficult to distinguish from one
another because one who sees depression as purely pathological certainly would
not agree with someone who sees it as purely a defense mechanism on how to
categorize a person working for a bad boss; the former would call this employee’s
(expected) affective state low mood, whereas the latter would argue that it is
depression. To clarify terminology, depression will refer to severe states of negative
affect that are often but not necessarily pathological. Low mood will refer to states in
the common range of normal experience.
Depression can be viewed as a manner of motivation. When the chances of
favorable conflict resolution are low, it is intuitive that people are likely to develop a
low mood. When this situation recurs chronically, depression may develop.
Depression is characterized by a more pervasive pessimism, low self-esteem, and
reduced initiative. The sadness, pain, and lack of motivation may in fact stimulate the
individual to change the situation; for instance, if you have an employer who is
abusive of their position, you may develop depression due to your repeated efforts to
maintain your self-esteem and resist your boss’s annoyance being ineffective.
Standing up to your boss may cost you your job, whereas not doing so will continue
to result in feelings of defeat, ultimately leading to depression. The idea behind this
viewpoint is that depression motivates you (the individual) to disengage the conflict.
By feeling depressed, you may become motivated to either yield to the hierarchy or
find a new job. This would be useful in the EEA for obvious reasons. If one is doing
poorly hunting and foraging food in a certain area, they should become upset with
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the area and find a new one. Furthermore, if others are successfully accessing
resources (hunting and foraging) in the same area, it would make sense to either
find an area with more readily accessible resources or to humble oneself and accept
the more successful people as superior in the hierarchy. Essentially, if one finds
themselves continually losing, they would be best served to conserve resources by
competing elsewhere or reducing competition (withdrawal and depression); on the
flip side, if one finds themselves to be successfully accessing resources repeatedly,
they would be best served to invest more of their resources (time, energy) in
competing for more resources (success, power, money, etc.).
However, it seems that loss is not responsible for depression as much as the
context of the loss; events involving humiliation and/or entrapment seem particularly
predictive of depression. Negative feelings and lack of motivation make sense in
situations involving major failure, loss, or inability to challenge a superior. This holds
true in practice, which presents a strong case for depression as a regulatory
mechanism. The researchers suggest that antidepressant medication should cause
recipients to be more willing to continue an action even when the action’s costs
exceed the benefits. By the same line, depression is likely to occur when the
individual lacks the resources to accomplish their goals, as well as when people are
ambitious, because they are more likely to fail to give up their goals in response to
failure. Additionally, this means (and is supported by research) that cultures with
more rigid hierarchies experience higher rates of depression (because of limited
upward mobility), and globalization of media should also increase depression by
encouraging individuals to pursue unreasonable goals.
Determining depression to be a defect, dysregulated defense, or well-formed
defense proved an irrelevant question, as all three occur in reality and categorization
depends primarily on the terminology and particular situation. The evolutionary
bases used to support the final conclusion are valid in animal and neural models,
and explain the development of depression in terms of the situations under which it
was shaped rather than those we in the current environment. It seems likely that low
mood and the negative effects that are associated with it help organisms deal with
unpropitious situations. These passive aspects inhibit dangerous or wasteful actions
such as challenging authority, the pursuit of unreachable goals, etc. It is important to
note, though, that this by no means suggests that depression is not a disease state.
Depression can manifest in the form of a disease, as a result of dysfunctional
regulation of a defense, or as . At the present time, we do not have enough empirical
evidence that suggests that depression is an adaptation, but after further research,
we should be able to prevent and relieve mood disorder and low moods that are
normal but unnecessary.
Outline
1.
Issue of different fundamental views
· Some researchers view depression from a purely pathological viewpoint
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o They see depression as a disease of the mind.
· Others see it as a defense mechanism, and still others see it as a
malformation or defect of a defense mechanism.
2.
Distinguishing Depression and low mood
·
Depression will refer to severe states of negative affect that are often
but not necessarily pathological.
·
Low mood will refer to states in the common range of normal
experience
3.
Functions of Depression
·
Depression is painful and interferes with normal function
4.
Global Evidence
·
Do the global characteristics of low mood or depression give clues
about their adaptive significance?
o
Since depression is painful and interferes with normal function
it seems maladaptive but other characteristics are useful
§
Nausea
§
Fatigue
o
The intrinsic aversiveness of low mood suggests it to be a
defense
·
Major depressive disorder affects 10% of the US population in a year
·
Depressive syndromes are even more common throughout a
population.
·
The incidence of depression is highest at the ages of reproductive
value which is a pattern characteristic of few diseases
·
Defenses are regulated by cues associated with situations in which
they are useful, defects are not
o
The regularity of relationship between loss and negative affect
and proportionality of low mood to the magnitude of loss imply that
mood is regulated
5.
Possible Functions
·
Depression in adults has the capacity to arose pity from others
o
Also has been interpreted as communication designed to
manipulate others into providing resources
·
Conservation-withdrawal is useful in that someone who is depressed
is saving energy during bad times.
·
Yielding in a hierarchy conflicts
o
Researchers noticed that people with depression were
unwilling to yield to a more powerful adversary
o
If they finally did, the powerful adversary would not see them as
a threat, the conflict would end and the depression would cease.
·
Depression is common in people who are pursuing unreachable goals
o
When a subject realizes that the goal is unobtainable, feelings
of sadness may be a useful stimulus in changing the situation
o
Also the low mood helps disengage the commitment and end
the cycle
6.
Situations in which depression is useful
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7.
8.
·
Decreased motivation and activity are very useful in situations that
may be futile or dangerous
·
Organisms carefully regulate when and where they exert effort
o
Foraging theory offers the prediction as food in a patch is
depleted, organisms give up on that patch at close to the optimal time
o
If a deer is foraging in the winter and the foraging for food may
cost the deer more energy than it can gain, its best option would be to
stand still and wait
Core Aspects that are useful
·
The start-up cost of another enterprise, be it marriage or another job,
are huge and the uncertainty that it will pay out is very large.
·
Depression is seen as a state shaped to cope with unpropitious
situations both to decrease investment in the current unsatisfying life
enterprise and also to prevent the premature pursuit of alternatives
·
Failure to disengage can cause depression
Conclusions
·
Its seems likely that low mood and related negative affects were
shaped to help organisms cope with unpropitious situations.
·
Some negative and passive aspects of depression are good in that
they inhibit wasteful and dangerous actions in situations characterized by;
o
The pursuit of an unreachable goal
o
Temptations to challenge an authority
o
Insufficient internal reserves to allow action without damage
·
An important aspect of depression is acknowledging that disease
states are one of the most serious medical problem in the world
Critical Review
Aggreances:
1.
Addresses (but does not fully resolve) the issue of terminology; how we
define “depression” versus “low mood” and other negative affects is absolutely key to
further research.
2.
Depression is not one thing and one thing only; depending on context and
viewpoint, it can be a disease of the mind, a defense and motivator against
unfavorable (or unpropitious) situations.
3.
Makes reasonable assumptions and conclusions regarding the possible
function of depression (i.e., in regards to conservation-withdrawal, hierarchy conflict
resolution, etc.)
Shortcomings:
1.
Failed to answer the first thesis laid out (depression as a defense/defect/malregulated defense.
2.
Does not call for more rigid and particular use of terms or for agreement on
terminology.
3.
Argument is poorly laid out; the author makes heavy use of and reference to
separate research, usually without pretense, and out of context from the questions
they answer (skips around often).
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Test Questions
1.
Research has shown that depression is likely a purely pathological state of
being. (T/F) [F]
2.
Depression is NOT generally useful for which of the following: [D]
a. conservation-withdrawal
b. Hierarchy conflict resolution
c. disengagement from unfavorable situations
d. a motivator for improving physical health
3.
Low mood is suspected to have evolved to help organisms deal with
unpropitious situations (T/F) [T]