The role of outcome expectancy in therapeutic change across psychotherapy versus pharmacotherapy for depression.

BACKGROUND: Patient outcome expectancy - the belief that treatment will lead to an improvement in symptoms - is linked to favourable therapeutic outcomes in major depressive disorder (MDD). The present study extends this literature by investigating the temporal dynamics of expectancy, and by exploring whether expectancy during treatment is linked to differential outcomes across treatment modalities, for both optimistic versus pessimistic expectancy. METHODS: A total of 104 patients with MDD were randomized to receive either cognitive behavioral therapy (CBT) or pharmacotherapy for 16 weeks. Outcome expectancy was measured throughout treatment using the Depression Change Expectancy Scale (DCES). Depression severity was measured using both the Hamilton Depression Rating Scale and Beck Depression Inventory-II. RESULTS: Latent growth curve models supported improvement in expectancy across both treatments. Cross-lagged panel models revealed that both higher optimistic and lower pessimistic expectancy at mid-treatment predicted greater treatment response in pharmacotherapy. For CBT, the associative patterns between expectancy and depression differed as a function of expectancy type; higher optimistic expectancy at pre-treatment and lower pessimistic expectancy at mid-treatment predicted greater treatment response. LIMITATIONS: The sample size limited statistical power and the complexity of models that could be explored. CONCLUSIONS: Results suggest that outcome expectancy improved during treatment for depression. Whether outcome expectancy represents a specific mechanism for the reduction of depression warrants further investigation

Representation of cognitive reappraisal goals in frontal gamma oscillations

Recently, numerous efforts have been made to understand the neural mechanisms underlying cognitive regulation of emotion, such as cognitive reappraisal. Many studies have reported that cognitive control of emotion induces increases in neural activity of the control system, including the prefrontal cortex and the dorsal anterior cingulate cortex, and increases or decreases (depending upon the regulation goal) in neural activity of the appraisal system, including the amygdala and the insula. It has been hypothesized that information about regulation goals needs to be processed through interactions between the control and appraisal systems in order to support cognitive reappraisal. However, how this information is represented in the dynamics of cortical activity remains largely unknown. To address this, we investigated temporal changes in gamma band activity (35-55 Hz) in human electroencephalograms during a cognitive reappraisal task that was comprised of three reappraisal goals: To decease, maintain, or increase emotional responses modulated by affect-laden pictures. We examined how the characteristics of gamma oscillations, such as spectral power and large-scale phase synchronization, represented cognitive reappraisal goals. We found that left frontal gamma power decreased, was sustained, or increased when the participants suppressed, maintained, or amplified their emotions, respectively. This change in left frontal gamma power appeared during an interval of 1926 to 2453 ms after stimulus onset. We also found that the number of phase-synchronized pairs of gamma oscillations over the entire brain increased when participants regulated their emotions compared to when they maintained their emotions. These results suggest that left frontal gamma power may reflect cortical representation of emotional states modulated by cognitive reappraisal goals and gamma phase synchronization across whole brain regions may reflect emotional regulatory efforts to achieve these goals. Our study may provide the basis for an electroencephalogram-based neurofeedback system for the cognitive regulation of emotion.open0