Emotional processing in bipolar disorder: Behavioural and neuroimaging findings

Abstract

Existing studies revealed that bipolar patients show an altered identification of emotional stimuli (e.g. facial expressions), however, so far modifications in early emotional processes and the regulation of emotions are less clear. In response to emotional stimuli bipolar patients show a dysfunction in a ventral-limbic brain network including the amygdala, insula, striatum, subgenual cingulate cortex, ventrolateral prefrontal cortex and orbitofrontal cortex. In most studies, a relative hypoactivity of dorsal brain structures, including the dorsolateral prefrontal cortex, the dorsal anterior cingulate and the posterior cingulate cortex, has been reported in bipolar patients. This imbalance between the two networks has been proposed to underlie deficient emotion regulation in bipolar disorder.

Impact of a microRNA MIR137 Susceptibility Variant on Brain Function in People at High Genetic Risk of Schizophrenia or Bipolar Disorder

“…In this case, the interpretation would be that the presence of the 'protective' allele is associated with normal amygdala function, and that those in the SCZ highrisk RISK + group without the protective allele do not demonstrate the expected deactivation during the task. It is notable that emotional processing bias and amygdala dysfunction has previously been reported in BD (Wessa and Linke 2009) and in their unaffected relatives . In apparent contrast to these findings, we found no association between MIR137 genotype and amygdala dysfunction in the bipolar high-risk sample.…”

The CACNA1C risk variant for bipolar disorder influences limbic activity

“…5 An enhanced amygdala activity is one of the most consistent findings from neuroimaging studies in symptomatic and remitted bipolar patients. 6,7 As the amygdala is activated in response to reward, 8 functional magnetic resonance imaging (fMRI) paradigms assessing reward-related brain activations provide the opportunity to investigate both the dysmodulation of motivation and reward and functional abnormalities in emotional processing brain regions, such as the amygdala.…”

“…This genotype effect in healthy individuals is very similar to findings from comparative neuroimaging studies that compared patients with bipolar disorder and healthy controls, namely, an enhanced limbic activation in response to emotional stimuli in patients. 7 It is not yet known whether the CACNA1C rs1006737 variant itself or a variant that is in linkage disequilibrium with it is causally linked to bipolar disorder. The present findings, however, show that variation at this locus has a significant impact on limbic activation in response to emotional stimuli.…”

Emotional and Motivational Processes in Bipolar Disorder: A Neural Network Perspective

“…In more detail, these mechanisms comprise a pre-attentive stage, attention allocation, sensory perception, transient and automatic emotional responses, experience and expression of emotion, higher-level appraisal of emotional stimuli, and finally the regulation of emotions [10]. From an experimental and clinical neuroscience perspective, it is important to make a distinction between these sub-processes in order to be able to validly characterize disturbed or maladaptive processes into psychopathologies.…”