Effects of behavioural activation on the neural basis of other perspective self-referential processing in subthreshold depression: a functional magnetic resonance imaging study

Abstract

BackgroundIt has been demonstrated that negatively distorted self-referential processing, in which individuals evaluate one's own self, is a pathogenic mechanism in subthreshold depression that has a considerable impact on the quality of life and carries an elevated risk of developing major depression. Behavioural activation (BA) is an effective intervention for depression, including subthreshold depression. However, brain mechanisms underlying BA are not fully understood. We sought to examine the effect of BA on neural activation during other perspective self-referential processing in subthreshold depression.MethodA total of 56 subjects underwent functional magnetic resonance imaging scans during a self-referential task with two viewpoints (self/other) and two emotional valences (positive/negative) on two occasions. Between scans, while the intervention group (n = 27) received BA therapy, the control group (n = 29) did not.ResultsThe intervention group showed improvement in depressive symptoms, increased activation in the dorsal medial prefrontal cortex (dmPFC), and increased reaction times during other perspective self-referential processing for positive words after the intervention. Also, there was a positive correlation between increased activation in the dmPFC and improvement of depressive symptoms. Additionally, there was a positive correlation between improvement of depressive symptoms and increased reaction times.ConclusionsBA increased dmPFC activation during other perspective self-referential processing with improvement of depressive symptoms and increased reaction times which were associated with improvement of self-monitoring function. Our results suggest that BA improved depressive symptoms and objective monitoring function for subthreshold depression.

The development of a low carbon binder produced from the ternary blending of cement, ground granulated blast furnace slag and high calcium fly ash: An experimental and statistical approach

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The neural correlates of the metacognitive function of other perspective

“…Consistent with our previous study 8, the left medial prefrontal cortex (BA8) showed significant activation in OS-P. The other region that showed significant activation was the left caudate nucleus.…”

“…During the course of BA interventions, participants monitor and assess their daily activities and work to change their habitual behaviors, such that pleasant events are increased and depressive symptoms are improved 21,22. We have previously reported that BA led to increased activation in the dmPFC during other perspective self-referential processing of positive trait words in individuals with subthreshold depression, which might contribute toward an improvement in depressive symptoms and the objective monitoring function 8. However, in our previous study 8, we did not directly assess the monitoring function with any self-report questionnaires or observer-rated scales.…”

“…Healthy individuals show increased dmPFC activation during positive self-referential processing, whereas individuals with depression show decreased dmPFC activation during positive self-referential processing 7. Furthermore, our previous study has indicated that behavioral activation (BA) increased activation in the dmPFC, which is associated with other perspective self-referential processing for positive words and that it is also correlated with an improvement in depressive symptoms 8. Also, several previous neuroimaging studies have suggested that dmPFC activation might reflect the metacognitive function 9,10.…”