# Depression and diminished capacity for pleasure



## David Baxter PhD (Aug 13, 2009)

Diminished cravings for pleasure linked to core depression symptom
? H E ? fulltxt :: email
posted Thursday, 13 August 2009

Melanie Moran - Vanderbilt University 

New research indicates that decreased cravings for pleasure may be at the root of a core symptom of major depressive disorder. The research is in contrast to the long-held notion that those suffering from depression lack the ability to enjoy rewards, rather than the desire to seek them. 

The research, led by Vanderbilt psychologists Michael Treadway and David Zald, is published in the online journal _PLoS One_. 

"This initial study shows that decreased reward processing, which is a core symptom of depression, is specifically related to a reduced willingness to work for a reward," Treadway, a graduate student in psychology, said. 

Decreased motivation to seek and experience pleasurable experiences, known as anhedonia, is a primary symptom of major depressive disorder. Anhedonia is less responsive to many antidepressants and often persists after other symptoms of depression subside. However, understanding the different components of anhedonia - the desire to obtain something pleasurable versus experiencing pleasure - has been difficult for researchers to determine in humans. 

"In the last decade and a half, animal models have found that the neurotransmitter dopamine, long known to be involved in reward processing, is involved in craving or motivation, but not necessarily enjoyment," Treadway said. "To date, research into reward processing in individuals with anhedonia has focused on enjoyment of rewards, rather than assessing the drive to work for them. We think this task is one of the first to do that." 

Treadway and his colleagues devised the Effort-Expenditure for Rewards Task, or EEfRT, to explore the role of reduced desire and motivation in individuals reporting symptoms of anhedonia. EEfRT involved having individuals play a simple video game that gave them a chance to choose between two different tasks, one hard, one difficult, to obtain monetary rewards. Participants were eligible but not guaranteed to receive money each time they completed a task successfully. 

The "hard" task required pressing a button 100 times within 21 seconds using one's non-dominant little finger and carried a potentially higher reward than the easy task, which required pressing a button 30 times in seven seconds using one's dominant index finger. The subjects were told at the beginning of each trial whether they had a high, medium or low probability of winning a prize if they successfully completed the trial. The participants could choose which trials they completed and were given 20 minutes to perform as many tasks as possible. 

The researchers found that subjects who reported symptoms consistent with anhedonia where less willing to make choices requiring greater effort in exchange for greater reward, particularly when the rewards were uncertain. 

"Consistent with our hypotheses, we found that individuals with self-reported anhedonia made fewer hard-task choices," the authors wrote. "These findings are consistent with theoretical models linking anhedonia to decreased (dopamine levels)." 

"By addressing the motivational dimension of anhedonia, our findings suggest a plausible theoretical connection between dopamine deficiency and reward processing in depression, which may eventually help us better understand how anhedonia responds to treatment," Treadway said. 

The study was supported by funding from Vanderbilt University and the National Institute on Drug Abuse. 

*Source:* Treadway MT, Buckholtz JW, Schwartzman AN, et al. Worth the 'EEfRT'? The Effort Expenditure for Rewards Task as an Objective Measure of Motivation and Anhedonia. _PLoS ONE_ 4(8):e6598   [Full text]


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## Andy (Aug 13, 2009)

I was actually looking up anhedonia the other day. I was wondering if it is possible to have chronic anhedonia? Is that a stupid question?


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## David Baxter PhD (Aug 13, 2009)

It's not a stupid question. I think the answer is yes.


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## Banned (Aug 13, 2009)

Would that in line then with dysthymia, or are they separate?


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## Andy (Aug 13, 2009)

Yeah, that's a good question Turtle. Would it be a symptom of dysthymia or the same...can it be a condition all on it's own?


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## David Baxter PhD (Aug 13, 2009)

Anhedonia is basically a symptom - inability to feel pleasure or loss of enjoyment in things that used to be or should be pleasurable.

It may be a symptom of dysthymia or depression. The major difference between the two is severity.


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## Daniel (Aug 13, 2009)

> "By addressing the motivational dimension of anhedonia, our findings suggest a plausible theoretical connection between dopamine deficiency and reward processing in depression, which may eventually help us better understand how anhedonia responds to treatment," Treadway said.





> "To date, research into reward processing in individuals with anhedonia has focused on enjoyment of rewards, rather than assessing the drive to work for them. We think this task is one of the first to do that."


My goodness.  This seems more like stuff that should have been done in the 1980s now that Wellbutrin has been widely available for depression.

In any case:



> Exercise is the best way to stimulate dopamine production.
> 
> movement.html


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## Andy (Aug 13, 2009)

One of the meds I am on is Wellbutrin. It doesn't always work I'm guessing.


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## David Baxter PhD (Aug 13, 2009)

STP said:


> One of the meds I am on is Wellbutrin. It doesn't always work I'm guessing.



In my experience, it's sometimes helfpul as an adjunct to an SSRI/SNRI, but of limited benefit as a stand-alone antidepressant.

It may also be helpful to counter side-effects of some SSRIs.

And it's sometimes used as adjunct therapy for bipolar disorder.


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## Andy (Aug 13, 2009)

I'm on...my pdoc explained this to me but I might not of took it in correctly. I am on meds that work on 3 neurotransmitters. DA,SNRI,Mood stabilizer/anti psych. That could be so wrong??
I am one of those people that has a hard time finding a cocktail that works and stays working. I have to increase my meds because they stop working on me, and I can only increase them so high. 
That could be what's happening with the wellbutrin and I am only on it as an agreement with my Dr.


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## David Baxter PhD (Aug 13, 2009)

STP said:


> I'm on...my pdoc explained this to me but I might not of took it in correctly. I am on meds that work on 3 neurotransmitters. DA,SNRI,Mood stabilizer/anti psych. That could be so wrong??
> 
> I am one of those people that has a hard time finding a cocktail that works and stays working. I have to increase my meds because they stop working on me, and I can only increase them so high.
> 
> That could be what's happening with the wellbutrin and I am only on it as an agreement with my Dr.



Yes, that sounds about right to me. 

And as always, continue to follow your doctor's advice - s/he is the person in the best position to give advice since s/he knows your full history.


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## Andy (Aug 13, 2009)

I know. I know:teehee: I'm trying to. It should be easier now that I can see him bi monthly.:goodjob:


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## Daniel (Aug 28, 2009)

For me, the article's best point is the uncertainty aspect:



> The researchers found that subjects who reported symptoms consistent with anhedonia where less willing to make choices requiring greater effort in exchange for greater reward,* particularly when the rewards were uncertain.*


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## Daniel (Oct 16, 2009)

*Re: Why expecting the worst is costly*

Regarding uncertain rewards:



> People’s positive moods lasted longer in the uncertain conditions.
> 
> The Pleasures of Uncertainty: Prolonging Positive Moods in Ways People Do Not Anticipate (PDF)


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