Disorder-specific characteristics of borderline personality disorder with co-occurring depression and its comparison with major depression: An fMRI study with emotional interference task.

Borderline personality disorder (BPD) and major depressive disorder (MDD) are both associated with abnormalities in the regulation of emotion, with BPD being highly comorbid with MDD. Disorder-specific dysfunctions in BPD, however, have hardly been addressed, hence the lack of knowledge pertaining to the specificity of emotion processing deficits and their commonality with MDD. 24 healthy comparison subjects, 21 patients with MDD, and 13 patients with comorbid BPD and MDD (BPD + MDD group) were studied using functional MRI. The subjects were required to perform an emotional interference task that entailed categorizing facial affect while ignoring words that labeled the emotional contents of the external stimuli. Collapsing across emotional face types, we observed that participants with BPD + MDD uniquely displayed a greater involvement of the visual areas and the cerebellum. During emotional conflict processing, on the other hand, the lateral prefrontal cortex (LPFC) appeared to be affected in both patient groups. In comparison to the HC, the MDD group showed differences also in the posterior medial frontal cortex (pMFC) and the inferior parietal lobule (IPL). Thus, our data indicate dysfunctionality in the neural circuitry responsible for emotional conflict control in both disorders. The enhanced visual cortex activation in BPD + MDD suggests the visual system's hyperresponsiveness to faces at an early perceptual level. Not being associated with co-occurring depression, this effect in BPD + MDD appears to represent specific personality traits such as disturbed reactivity toward emotionally expressive facial stimuli.

Brain circuitries involved in emotional interference task in major depression disorder.

BACKGROUND: Emotional and non-emotional Stroop are frequently applied to study major depressive disorder (MDD). The versions of emotional Stroop used in previous studies were not, unlike the ones employed in the present study, based on semantic incongruence, making it difficult to compare the tasks. METHODS: We used functional magnetic resonance imaging (fMRI) to study the neural and behavioral responses of 18 healthy subjects and 18 subjects with MDD to emotional and non-emotional word-face Stroop tasks based on semantic incompatibility between targets and distractors. RESULTS: In both groups, the distractors triggered significant amounts of interference conflict. A between-groups comparison revealed hypoactivation in MDD during emotional task in areas supporting conflict resolution (lateral prefrontal cortex, parietal and extrastriate cortices) paralleled by increased response in the right amygdala. Response in the amygdala, however, did not vary between conflicting and non-conflicting trials. While in the emotional (compared to non-emotional) task healthy controls showed considerably stronger involvement of networks related to conflict resolution, in patients, the processing differences between the two conflict types were negligible. LIMITATIONS: The patients group was inhomogeneous in terms of medication and clinical characteristics. The number of female participants was higher, due to which gender effects could not be studied or excluded. CONCLUSION: Whilst healthy controls seemed able to adjust the involvement of the network supporting conflict resolution based on conflict demand, patients appeared to lack this capability. The reduced cortical involvement coupled with increased response of limbic structures might underlie the maladjustment vis-à-vis new demands in depressed mood.

Brain circuitries involved in semantic interference by demands of emotional and non-emotional distractors.

BACKGROUND: Previous studies have indicated that the processes leading to the resolution of emotional and non-emotional interference conflicts are unrelated, involving separate networks. It is also known that conflict resolution itself suggests a considerable overlap of the networks. Our study is an attempt to examine how these findings may be related. METHODOLOGY/PRINCIPAL FINDINGS: We used functional magnetic resonance imaging (fMRI) to study neural responses of 24 healthy subjects to emotional and non-emotional conflict paradigms involving the presentation of congruent and incongruent word-face pairs based on semantic incompatibility between targets and distractors. In the emotional task, the behavioral interference conflict was greater (compared to the non-emotional task) and was paralleled by involvement of the extrastriate visual and posterodorsal medial frontal cortices. In both tasks, we also observed a common network including the dorsal anterior cingulate, the supplemental motor area, the anterior insula and the inferior prefrontal cortex, indicating that these brain structures are markers of experienced conflict. However, the emotional task involved conflict-triggered networks to a considerably higher degree. CONCLUSIONS/SIGNIFICANCE: Our findings indicate that responses to emotional and non-emotional distractors involve the same systems, which are capable of flexible adjustments based on conflict demands. The function of systems related to conflict resolution is likely to be adjusted on the basis of an evaluation process that primarily involves the extrastriate visual cortex, with target playing a significant role.