Anhedonia, the loss of pleasure or interest in previously rewarding stimuli, is a core feature of major depression. While theorists have argued that anhedonia reflects a reduced capacity to experience pleasure, evidence is mixed as to whether anhedonia is caused by a reduction in hedonic capacity. An alternative explanation is that anhedonia is due to the inability to sustain positive affect across time. Using positive images, we used an emotion regulation task to test whether individuals with depression are unable to sustain activation in neural circuits underlying positive affect and reward. While upregulating positive affect, depressed individuals failed to sustain nucleus accumbens activity over time compared with controls. This decreased capacity was related to individual differences in selfreported positive affect. Connectivity analyses further implicated the fronto-striatal network in anhedonia. These findings support the hypothesis that anhedonia in depressed patients reflects the inability to sustain engagement of structures involved in positive affect and reward.anhedonia ͉ emotion regulation ͉ nucleus accumbens

Evidence is accumulating for physical activity as an effective, well-tolerated, highly rewarding complementary behavioral intervention for enhancing quality of life (QOL) as well as fitness among individuals with chronic and even terminal illnesses. However, relatively few studies have examined the feasibility and potential health benefits of supervised, structured exercise programs for sedentary women with primary breast cancer. Forty women over the age of 45 with primary breast cancer participated in a course of group exercise training (GET) delivered in a structured format three times per week for 16 weeks. GET emphasizes physical activities that promote aerobic fitness, strength, and flexibility. Assessments of fitness/vigor and QOL were conducted prior to, during, and upon completion of the program. Results demonstrated that GET was feasible, safe, and well-tolerated. Moreover, the participants experienced significant health benefits over the course of the intervention in multiple dimensions of fitness/vigor (aerobic capacity, strength, flexibility) as well as QOL (increased positive affect, decreased distress, enhanced well-being, and improved functioning). Discussion highlights the need for inclusion of physical activity programs in comprehensive, complementary treatment regimes for breast cancer patients.

Objective Deficits in positive affect and their neural bases have been associated with major depression. However, whether reductions in positive affect result solely from an overall reduction in nucleus accumbens activity and fronto-striatal connectivity or the additional inability to sustain engagement over time of this network is unknown. Accordingly, we sought to determine whether treatment-induced changes in the ability to sustain nucleus accumbens activity and fronto-striatal connectivity during the regulation of positive affect are associated with gains in positive affect. Method Using fMRI, we assessed the ability to sustain activity in reward-related networks when attempting to increase positive emotion during performance of an emotion regulation paradigm in 21 depressed patients prior to, and after 2 months of antidepressant treatment. 14 healthy control subjects were scanned over the same interval. Results After 2 months of treatment, self-reported positive affect increased. Those patients demonstrating the largest increases in sustained nucleus accumbens activity over the 2 months were those demonstrating the largest increases in positive affect. In addition, those patients demonstrating the largest increases in sustained fronto-striatal connectivity were also those demonstrating the largest increases in positive affect when controlling for negative affect. Healthy controls showed none of these associations. Conclusions Treatment induced changes in the sustained engagement of fronto-striatal circuitry tracks the experience of positive emotion in daily life. Studies examining reduced positive affect in a variety of psychiatric disorders might benefit from examining the temporal dynamics of brain activity when attempting to understand changes in daily positive affect.

Self-system therapy (SST) is a new therapy based on regulatory focus theory (E. T. Higgins, 1997) for depressed individuals unable to pursue promotion goals effectively. The authors conducted a randomized trial comparing SST with cognitive therapy (CT) in a sample of 45 patients with a range of depressive symptoms to test 2 hypotheses: that SST would be more efficacious for depressed individuals characterized by inadequate socialization toward pursuing promotion goals and that SST would lead to greater reduction in dysphoric responses to priming of promotion goals. There was no overall difference in efficacy between treatments, but patients whose socialization history lacked an emphasis on promotion goals showed significantly greater improvement with SST. In addition, SST patients showed a greater reduction in dysphoric responses to promotion goal priming than did CT patients. The results illustrate the value of a theory-based translational approach to treatment design and selection.

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