Friday, March 05, 2010

Depression's Cognitive Downside



Author and blogger Jonah Lehrer has a lengthy (and controversial) essay in the Feb. 28 New York Times Magazine on Depression's Upside. The main idea, that depression has cognitive and evolutionary advantages, was largely based on a review paper by Andrews and Thomson (2009). In it, they put forth the analytical rumination hypothesis: depression is an evolved response to complex problems, and focusing on them to the exclusion of everything else is beneficial. Lehrer's piece generated an outpouring of comments (both pro and con), questions, and critiques. One notably critical rejoinder (The Myth of Depression’s Upside) was written by Dr. Ronald Pies, the Editor in Chief of Psychiatric Times:
Now, with all due respect to Dr. Thomson, I am inclined to ask, “[Insights gained during depression are] worth it to whom?” Perhaps the patients Dr. Thomson has treated emerge from their three-month bouts of depression saying, “Ya know what, Doc? It’s been a bad three months—lost my job, almost killed myself, and couldn’t get a damn thing done—but overall, it was worth it!” The depressed patients I evaluated over the past nearly 30 years almost never reported that their major depressive episodes had a “net mental benefit,” to quote Lehrer’s article. Most felt that their lives and souls had been stolen from them for the duration of their depressive episode.
In other words, Dr. Pies's patients don't feel like they've solved all their problems. Most of the studies cited in favor of improved problem-solving abilities involved a sad "mood induction" procedure such as watching a 10 min film showing a death from cancer or being given false negative feedback on cognitive test performance (Forgas, 2007). It should be obvious that a transient, slightly sad state is drastically different from a prolonged major depressive episode. Jonah does acknowledge this in his article, but the distinction appears to undermine Andrews and Thomson's entire basis for asserting analytical advantages for the depressed ruminator. It's another in a long line of evo psych just-so stories.

The literature is filled with papers describing the cognitive impairments associated with major depression. Jonah recognizes this as well, but then overstates how easy it is to dispense with the deficits:
The end result is poor performance on tests for memory and executive function, especially when the task involves lots of information. (These deficits disappear when test subjects are first distracted from their depression and thus better able to focus on the exercise.)
On the contrary, numerous papers have shown that impairments in cognitive processes such as executive control, attention, and memory persist after a depressed person has recovered (Andersson et al., 2010; Baune et al., 2010; Hammar et al., 2009). In actively depressed patients, Baune and colleagues (2010) found impairments in all domains tested: immediate memory, visuospatial construction, language, attention, and delayed memory. These deficits can contribute to lower social and occupational functioning and a diminished quality of life. In addition, depression can be associated with declines in problem solving abilities on neuropsychological tests such as the Wisconsin Card Sorting Test and the Tower of London test.

A recent review of the literature provided additional support for the existence of pervasive cognitive deficits (Hammar et al., 2009):
Research during the past decade has mainly focused on cognitive functioning in the severe phase of depression, and today it is widely accepted that the disease is characterized by cognitive impairment in the acute state. There are reports of findings in different cognitive domains, such as executive functions, attention, memory and psychomotor speed.
Well (you say), what about Social Dilemmas? Aren't these different from the Stroop task? The Psych Review manifesto on the Bright Side of Being Blue states that "Complex social problems may be the primary evolutionarily relevant trigger of depression in human beings." But support for the view that depression improves the ability to solve such problems is meager, apparently consisting of two old papers (Hokanson et al., 1980; Pietromonaco & Rook, 1987). The Hokanson paper turns out to be not-so-great for the analytical rumination hypothesis: (1) The "depressed" group had scores on the Beck Depression Inventory of 10 or greater, which includes those with only very mild depression. (2) Ironically, Hokanson et al. view their own results as evidence of social skills deficits, not enhanced social problem solving:
If, indeed, depressed individuals display different social responses, depending on situational or social role variables, one might expect that real-world relations are characterized by contradictory behaviors, mixed messages, emotional ambivalence, and so forth. Such stimulus arrays may indeed evoke several competing response tendencies in others, a situation that a simple reinforcement-punishment view would be hard pressed to handle.
The conclusion of the Pietromonaco and Rook (1987) paper is even more problematic:
This work suggests that depressives' cognitive analysis of common life situations leads them to make decisions that promote their social isolation and, thereby, perpetuate their depression.
The analytical rumination hypothesis even has the potential to be harmful. Belief in the glorious "upside" of their ailment could prevent some severely depressed individuals from getting proper treatment, placing them at greater risk of suicide and other adverse events. Needless to say, such an outcome would be of no evolutionary advantage.

References

Andersson S, Lövdahl H, Malt UF. (2010). Neuropsychological function in unmedicated recurrent brief depression. J Affect Disord. Jan 18. [Epub ahead of print]

Andrews PW, Thomson JA Jr. (2009). The bright side of being blue: depression as an adaptation for analyzing complex problems. Psychol Rev. 116:620-54.

ResearchBlogging.org

Baune, B., Miller, R., McAfoose, J., Johnson, M., Quirk, F., & Mitchell, D. (2010). The role of cognitive impairment in general functioning in major depression. Psychiatry Research DOI: 10.1016/j.psychres.2008.12.001

Forgas JP (2007). When sad is better than happy : Negative affect can improve the quality and effectiveness of persuasive messages and social influence strategies. J Exp Social Psychol. 43:513-528.

Åsa Hammar, Guro Årdal (2009). Cognitive functioning in major depression – a summary Frontiers in Human Neuroscience. DOI: 10.3389/neuro.09.026.2009

Hammar A, Sørensen L, Ardal G, Oedegaard KJ, Kroken R, Roness A, Lund A. (2009). Enduring cognitive dysfunction in unipolar major depression: A test-retest study using the Stroop paradigm. Scand J Psychol. 2009 Dec 23.

Hokanson JE, Sacco WP, Blumberg SR, Landrum GC. (1980). Interpersonal behavior of depressive individuals in a mixed-motive game. J Abnorm Psychol. 89:320-32.

Pietromonaco PR, Rook KS. (1987). Decision style in depression: The contribution of perceived risks versus benefits. J Personality Social Psychology 52:399-408.


Supplementary Material

Below is a box/blob and arrow diagram of the analytic rumination model (click on image for a larger view). A critique of its ludicrous biological underpinnings is beyond the scope of this post.

Figure 1 (Andrews & Thomson, 2009). A diagram of the proposed causal relationships between the variables and the constructs that are prominent in the analytical rumination hypothesis. The diagram uses the terminology of structural equation modeling [NOTE: but none of its quantitative rigor], with the circles representing latent constructs, the rectangles representing manifest variables, and the arrows denoting the hypothesized direction of causation. The plus (+) sign denotes a positive or facilitative causal relationship between variables, and the minus (-) sign denotes a negative or inhibitory causal relationship. 5-HT = 5-hydroxytryptamine or serotonin; L-VLPFC = left ventrolateral prefrontal cortex; R-VLPFC = right ventrolateral prefrontal cortex; WM = working memory.

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17 Comments:

At March 05, 2010 7:15 AM, Anonymous CM said...

Thankyou very much for this post, I tried to comment on Jonah's post but found it hard to remain dispassionate and get my point across clearly. This is spot on. The last paragraph nails it. Thankyou, thankyou, thankyou.

 
At March 05, 2010 10:57 AM, Blogger SustainableFamilies said...

Here's the thing, is it possible that some people have legitimately been through more misery and therefore a depressed mood is more accurate and therefore possibly more healthy?

I.e possibly the person who works through the thoughts emotions and grief will be better off than someone who numbs or superficially induces happiness with meds?

That's a well known theory, what are your thoughts on that?

I understand that during and even after a depressed period a person may fall behind in many areas of life those who never had depression, however that doesn't mean we know it wasn't something they needed to go through rather than suppress.

Or do we?

More studies seem to coming out linking childhood abuse, neglect, rape, incest etc with depression, and I'm sure that in these cases we should expect there to be no cognitive/emotional affects on people who have gone through such things.

It could be that people with depression have also often experienced life events that have impaired their cognitive abilities and their perceptions about their fellow human beings.

 
At March 05, 2010 11:13 AM, Anonymous Anonymous said...

Thank you for posting the excellent "take down" of the so-called analytic-rumination hypothesis, first posed on Psydir.

Incidentally, there is no credible evidence that antidepressant medication--which I emphatically do not recommend for ordinary "grief" or sorrow!--"numbs" the depressed individual or "induces happiness."

Antidepressants appear to work by inducing changes at the level of the gene, probably affecting nerve growth factors, such as BDNF. (One caveat: in perhaps 10-20% of patients taking a purely serotonergic agent, the medication sometimes does "blunt" affect or mildly interfere with cognition--but this is a minuscule effect, compared with the effect of major depression itself). For more on the mechanism of action of antidepressants, please see my remarks on Jonah Lehrer's website.
http://scienceblogs.com/cortex/2010/03/critiques.php

Ronald Pies MD

 
At March 05, 2010 2:12 PM, Blogger SustainableFamilies said...

Ok, so I'm pretty far from an MD but as a "lay person" if you will this subject is particularly interesting to me. I could try to google DNA changes through life but you probably already have seen the study I'm thinking of that discuss that DNA actually changes through out our lives and in a number of different ways.

So here's a question, could DNA be negatively influenced by a depressed mood, and further, could DNA be positively influenced by a positive mood?

People seem to say that because biological changes are present in depressed patients that dictates causality but there is nothing that proves that the biological changes don't result from the emotions, or the traumatic experiences a person has gone through.

Biological depression may not be a disease so much as an observable physical and biological condition that results from having a normal response to an abnormal situation.

(Depression is such a vague term and I believe there are a huge number of variables that cause the various states that are labeled as "depression" so it's often hard discussing it in it's most generalized form.)

So going back to observable biological "malfunction" in the brain, could it be that these observable problems may heal with time if the depressed person moved through the depressed emotions and was living a healthy life with healthy lifestyle changes?

(PS I'm not going to be sold on psych meds ever, but I'm equally skeptic of new agey cures... the science behind all this is intriguing and important. Be skeptic. Be skeptic of skepticism... lol)

 
At March 05, 2010 4:56 PM, Anonymous Anonymous said...

I'm glad to read this. Having experienced severe depression, I can say for sure that for me (and it could be different for other people) it most definitely did not make me think more clearly or have any better understanding of the world whatsoever. It made everything, including thinking on the most basic level, very very difficult.

And antidepressants have not numbed my emotions or made me feel happy and unaware of any underlying problems. They've made me able to think clearly and have taken away or reduced the symptoms of depression, so that I'm more able to experience the normal emotions which were numbed when I was depressed.

My experience of depression has taught me what it's like to be depressed. I think I can empathise with people with horrible problems more than perhaps I could have otherwise, which might make me better at my job working with people with mental health problems. But it's not worth it, and I probably could have achieved a lot more had I not suffered from depression (and I mean suffered not experienced).

It really annoys and offends me when people think that arguing against medication = standing up for people with depression, when they clearly have no understanding of the difference between depression and unhappiness. So I appreciate you questioning them, and hope you'll carry on.

 
At March 06, 2010 5:50 AM, Blogger The Neurocritic said...

Anonymous - It does seem rather insulting to be told that the pain and suffering of severe depression is adaptive. Can't think or analyze anything? Failed to gain any insight from your depression? It doesn't matter! In fact, there's nothing wrong with you. You don't even have a disorder:

"There is another possibility: that, in most instances, depression should not be thought of as a disorder at all. In an article recently published in Psychological Review, we argue that depression is in fact an adaptation, a state of mind which brings real costs, but also brings real benefits."
-Andrews & Thomson, Depression's Evolutionary Roots (Aug 2009 SciAm).

CM - I did notice that you commented on Jonah's latest entry in the debate, More on Depression. Thanks for mentioning this post.

Dr. Pies - Thanks very much for your comments and your ongoing contributions to this debate from the perspective of a psychiatrist who treats mood disorders.

One small note: PsyDir actually steals content without permission and without obvious attribution (in some cases, the links don't show the original source).

SustainableFamilies - You asked a lot of questions here. Is depression a rational response to an insane world? Is suffering better than numbing? For the latter, it depends on what you mean by "works through" -- working through one's emotions and grief does not require that you be depressed. "Inducing happiness with meds" applies more accurately to drugs of abuse than to antidepressants.

I'm completely puzzled by your comment that childhood abuse, neglect, rape, incest etc should not cause cognitive/emotional effects on those who have gone through such things. Why would they NOT cause cognitive/emotional effects??

 
At March 06, 2010 10:52 AM, Blogger SustainableFamilies said...

I must have not spoken clearly! I do believe such things can cause cognitive damage!! I was saying (forgive me if this is unclear again)

If depression is correlated with trauma, difficult life experience, and difficult childhoods, and cognitive impairment is correlated with the same things, it would be hard to determine which caused what.

Ie did the trauma cause the depression which caused the cognitive impairment? Or did the cognitive impairment occur due to the factors that caused the depression in the first place?

Does that make my question more clear, or more confuddled...? hmmm.

The question may have been answered by this research, I'm not savvy enough to see if they addressed this.

 
At March 06, 2010 1:55 PM, Anonymous Anonymous said...

Anonymous... you wrote:
I'm glad to read this. Having experienced severe depression, I can say for sure that for me (and it could be different for other people) it most definitely did not make me think more clearly or have any better understanding of the world whatsoever.
...
It really annoys and offends me when people think that arguing against medication = standing up for people with depression, when they clearly have no understanding of the difference between depression and unhappiness. So I appreciate you questioning them, and hope you'll carry on.

I could have written just the same... Thanks for explaining it here. I too had one severe depression (and 2 depressions that were not so deep). And it's true: it's the hell you're in. It's dying or really, really hoping you'll die. Because you can't stand it anymore. I remember the day, after +/- 5 months, that I saw for the first time in these 5 months that the sun was shining and that the flowers were deeply red. For a few seconds I realized it, again. It felt well, even if it was still short. But it was the beginning of being better... After 5 months I felt some beauty again. All the prvious months, the only thing I felt was darkness, sadness, severe anxiety and grief.

So it makes me angry too when reading that sort of nonsense of 'adaptive', 'no medication', etc...

MP

 
At March 07, 2010 9:38 AM, Blogger Unknown said...

I have had severe depression with several serious suicide attempts, including one hospitalization.... This work on the adaptive potential for depression is actually uplifting for me.

This is because in my deepest, grayest of depressions I have come up with the best research work (as did Darwin and Newton). I view these depressive moods as a dangerous gift, as does the Icarus project, http://theicarusproject.net/ . I think it is insulting and intolerably cruel to tell a human being that they are fundamentally cognitively impaired for the rest of their life unless they constantly take medication.

 
At March 07, 2010 11:00 AM, Blogger The Neurocritic said...

SustainableFamilies - It would seem that trauma can cause both depression and cognitive impairment. Trauma can also cause PTSD of course, which has been associated with cognitive impairments as well. Although there is high co-morbidity between depression and PTSD, they are distinguishable from each other and from prolonged grief disorder.

MP - Thanks for giving such an eloquent description of what it was like to emerge from a severe depression.

Erick - I'm glad you were able to be productive during your depressive episodes. Other commenters have considered their severe depressions to be a living hell, not a gift. And your view on medication is not shared by all. Some think it would be insulting and intolerably cruel to be denied the right to take antidepressant medications.

 
At March 07, 2010 12:25 PM, Blogger Unknown said...

Neurocritic: I agree that nobody should be denied the right to take any drugs whatsoever needed to help them (including those other than antidepressants). That is intolerably cruel to people who struggle with their depression. Saying that there is no other option besides medication for those who want to excel in life is just as cruel. This is especially true for those who do not respond to medication, who are, by your argument, condemned to lifelong idiocy.

 
At March 07, 2010 12:50 PM, Blogger The Neurocritic said...

I never recommended that everyone must take antidepressants (or mood stabilizers) for their depression. Of course there are drug-free options, and of course people are free to choose them.

I don't see where I said that those who are medication-resistant are "condemned to lifelong idiocy" -- that's rather inflammatory and not a very effective way of making your point.

Actually, the post cites studies showing that people who *do* respond to medications and go into remission still show some deficits on cognitive tests. That doesn't make them all idiots.

 
At March 07, 2010 1:45 PM, Blogger Unknown said...

I agree you didn't directly state that.

However, you presented evidence that depression untreated by medication has been linked to cognitive impairment. A logical conclusion from this is that those depressed folks who are not on medication are cognitively impaired. Many individuals who do not respond to medication go off of it. They are thus, by your argument, going to be cognitively impaired. This is far from idiocy, I agree that was overstated and inflammatory.

 
At March 10, 2010 8:47 PM, Blogger The Neurocritic said...

Dave - Thank you for alerting the readers to your new post (and for mentioning my piece there). It's "complexicated"...

 
At March 17, 2010 2:12 AM, Blogger Neuroskeptic said...

I'm far from being convinced that depression has to have an evolutionary purpose. Sadness presumably does because it's something that happens to everyone, but severe depression is quite rare and that suggests it's not all that useful. Also, I think it is unlikely that psychosis or full-blown mania are adaptive - they seem fairly clearly pathological - severe depression is just as, well, severe, so I'm pretty sure it is too.

As I said, sadness as an emotion is another story. And bereavement. I think if you read what people say about "depression's upside" to refer to those states instead of severe depression, it makes more sense.

 
At March 17, 2010 3:00 AM, Blogger The Neurocritic said...

Jonah is actually more measured in his article than Andrews and Thomson (2009) are in their Psych Review paper. The analytic rumination hypothesis dismisses any distinction between sadness and severe depression:

“It is not uncommon to see arguments that depression might be adaptive at low levels but is maladaptive at levels that reach DSM criteria (Dobson & Pusch, 1995; P. Gilbert & Allan, 1998; L. Lee, Harkness, Sabbagh, & Jacobson, 2005; Markman & Miller, 2006; Nettle, 2004; Price et al., 1994; Wolpert, 2008). These arguments implicitly assume that clinical and subclinical episodes are qualitatively different. Because we think that the clinical significance criterion leads to the overdiagnosis of depressive disorder, we intend our arguments to apply to a range of depressive symptoms, from transient sadness to much of what would currently satisfy DSM–IV–TR criteria for major depression. A good deal of evidence supporting the analytical rumination hypothesis comes from samples that satisfy DSM criteria, and there is little evidence that clinical depression is qualitatively different from subclinical depression…”

There is one highly adaptive aspect of mania, however, that confers a reproductive advantage: hypersexuality!

 
At August 01, 2010 1:11 AM, Anonymous Karl the Depression Helper Guy said...

The article was well researched, carefully considered. Not to mention... the theory is out there. I agree with the comment of SustainableFamilies. I believe that aside from emotions, depression can be get from our mindset. Over thinking can cause you depression and may lead to mental disorder, as what i've noticed. Better ask any medical authority if these may arise. Or someone knowledgeable and experience to handle such stress and depression problems.

 

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