Depression may sap endurance of brain reward circuits

[David Baxter PhD]

Depression may sap endurance of brain reward circuits
Anxiety Insights
Wednesday, 23 December 2009

A new study at the University of Wisconsin-Madison suggests that depressed patients are unable to sustain activity in brain areas related to positive emotion.

The study challenges previous notions that individuals with depression show less brain activity in areas associated with positive emotion. Instead, the new data suggest similar initial levels of activity, but an inability to sustain them over time. The new work was reported in the Proceedings of the National Academy of Sciences.

"Anhedonia, the inability to experience pleasure in things normally rewarding, is a cardinal symptom of depression," explains UW-Madison graduate student Aaron Heller, who led the project. "Scientists have generally thought that anhedonia is associated with a general reduction of activity in brain areas thought to be important for positive emotion and reward. In fact, we found that depressed patients showed normal levels of activity early on in the experiment. However, towards the end of the experiment, those levels of activity dropped off precipitously.

"Those depressed subjects who were better able to sustain activity in brain regions related to positive emotion and reward also reported higher levels of positive emotion in their everyday experience," Heller continues.

"Being able to sustain and even enhance one's own positive emotional experience is a critical component of health and well-being," notes the study's senior author, Richard Davidson, professor of psychology and psychiatry and director of both the UW-Madison Center for Investigating Healthy Minds, and the Waisman Laboratory for Brain Imaging and Behavior. "These findings may lead to therapeutic interventions that enable depressed individuals to better sustain positive emotion in their daily lives."

During the study, 27 depressed patients and 19 control participants were presented with visual images intended to evoke either a positive or a negative emotional response. While viewing these images, participants were instructed to use cognitive strategies to increase, decrease or maintain their emotional responses to the images by imagining themselves in similar scenarios. Heller and colleagues used functional magnetic resonance imaging (fMRI) to measure brain activity in the target areas. The researchers examined the extent to which activation in the brain's reward centers to positive pictures was sustained over time.

The study was funded by grants from the National Institute of Mental Health, Wyeth-Ayerst Pharmaceuticals, Fetzer Institute and Impact Foundation, and by gifts from the John W. Kluge Foundation, Bryant Wangard, Ralph Robinson and Keith and Arlene Bronstein.

Reference
Heller AS, Johnstone T, Shackman AJ, et al. Reduced capacity to sustain positive emotion in major depression reflects diminished maintenance of fronto-striatal brain activation. Proc Natl Acad Sci U S A. 2009 Dec;doi:10.1073/pnas.0910651106 [Abstract | Full text ]

 

[Daniel E.]

Positive Psychology interventions may help people with clinical depression
By Dr. Steve Balt
Retrieved November 15, 2011

Patients with depression often complain of pervasive feelings of sadness and low self-esteem. So it only makes sense that “thinking positively” about oneself might be a way to overcome the ravages of this disorder. Unfortunately, modern methods tend to shun this common-sense technique (perhaps assuming that patients have already tried such “obvious” approaches) and instead rely on more complex psychotherapeutic methods or psychotropic medications.

Recently, however, researchers from Duke University and the Positive Psychology Lab at the University of California-Riverside have reviewed the literature on “positive activity interventions,” and find that their effects are comparable to other interventions for patients with mild clinical depression.

The types of positive interventions employed by investigators vary widely. Some examples: “writing letters of gratitude, counting one’s blessings, practicing optimism, performing acts of kindness, meditating on positive feelings towards others, and using one’s signature strengths.” What they all have in common is that each helps the patient “bypass” the cognitions and self-talk that perpetuate depression, and instead strengthens the pleasure circuits that seem, in most patients, to have gone off-line. More importantly, they all empower patients and can be implemented conveniently, cheaply, and with little stigma and no side effects.

And the data show that they seem to work. Although the trials to date have generally enrolled patients who choose to participate in Positive Activity Interventions (in other words, they are not randomly assigned to the procedure), they have shown effect sizes comparable to those for drugs and for psychotherapy. Furthermore, the benefit of positive activities may even have a measurable neuroanatomical basis. Depressed patients typically have lower ventral striatum activity (a part of the brain that is associated with limbic structures, such as the amygdala, hippocampus, midline thalamus, and certain regions of the prefrontal cortex). They also show lower left frontal-lobe activity in response to positive stimuli, a phenomenon has been shown to be more normal when patients recover.

Thus, it is quite possible that the therapeutic administration of activities that bolster one’s sense of positivity—rather than the frequently Herculean challenge to overcome one’s negative beliefs—may prove to be an effective antidepressant technique. Now, the task for clinicians and researchers is to identify how to incorporate this deceptively simple complementary approach into their practices.

Here is the reference for this study:

Layous, K., Chancellor, J., Lyubomirsky, S., Wang, L., & Doraiswamy, P. M. (2011). Delivering happiness: translating positive psychology intervention research for treating major and minor depressive disorders. Journal of Alternative and Complementary Medicine, 17(8), 1-9.

---------- Post added at 08:11 PM ---------- Previous post was at 07:49 PM ----------

From the PDF paper above by Layous et al:

As one example, Seligman and colleagues conducted an online experiment in which they randomly assigned 411 volunteers—who were mildly depressed, on average, with a mean score of 14.1 on the Center for Epidemiologic Studies Depression scale (CES-D)—to engage for 1 week in one of five well-being–enhancing activities (involving practicing gratitude, positive thinking, and one’s strengths) versus a placebo control activity (involving writing one’s early experiences). Participants in the placebo condition experienced a short-term boost, but returned to their baseline after a week. By contrast, those who completed the positive exercises experienced a boost in well-being and a decline in depressive symptoms, and these benefits were maintained after the intervention ended. Two (2) of the activities—writing about three good things in one’s life and using one’s signature strengths in a new way—resulted in lasting improvements in depression and well-being for 6 months. This study demonstrates that even simple, self-guided exercises can bring long-term benefits to mildly depressed or dysphoric individuals...

Notably, every treatment group in the abovementioned study showed significant decreases in depressive symptoms after just 1 week or less of participation. These results indicate that not only can PAIs [positive activity interventions] be effective in reducing depressive symptoms, but that they can also work quickly. In another study, Seligman instructed severely depressed individuals (CES-D mean of 33.9) to engage in the ‘‘three good things’’ PAI every day. Within 15 days, participants’ CES-D scores decreased by 16.7 points (from severe to mild-to-moderate depression) and 94% experienced relief. Thus, although the development, research, and implementation of positive psychology interventions are in their early stages, such interventions show promise for improving the lives of many, and doing so at a relatively rapid pace.