Neural functional correlates of empathic face processing.

OBJECTIVES: Empathy is a human trait related to the ability to share someone else's feelings, and emotional face processing is one of its measures. Functional Magnetic Resonance Imaging (fMRI) studies showed significant neural correlates of empathic face processing. We aimed to identify those brain areas most consistently involved in empathy for emotional faces. METHODS: We carried ALE meta-analysis of whole-brain data from fMRI studies during empathic face-processing tasks. We included 23 studies conducted on a total of 568 participants (247 males and 321 females, mean age 32.2 years). RESULTS: Emotional vs. control faces processing significantly correlated with activations of the left anterior cingulate cortex (BA 32), right precentral gyrus (BA 6), left amygdala, right superior frontal gyrus (BA 9), left middle occipital gyrus (BA 37), right insula (BA 13), left putamen, and left posterior cingulate cortex (BA 31). CONCLUSIONS: Empathy is a complex process correlating with bi-hemispheric cortico-limbic activations involved in emotional cue processing, self-other/same-different discrimination, perspective-taking, theory of mind, emotional arousal, and decision-making.

Neurobiological Evidence for the Primacy of Mania Hypothesis.

BACKGROUND: Athanasios Koukopoulos proposed the primacy of mania hypothesis (PoM) in a 2006 book chapter and later, in two peer-reviewed papers with Nassir Ghaemi and other collaborators. This hypothesis supports that in bipolar disorder, mania leads to depression, while depression does not lead to mania. OBJECTIVE: To identify evidence in literature that supports or falsifies this hypothesis. METHOD: We searched the medical literature (PubMed, Embase, PsycINFO, and the Cochrane Library) for peer-reviewed papers on the primacy of mania, the default mode function of the brain in normal people and in bipolar disorder patients, and on illusion superiority until 6 June, 2016. Papers resulting from searches were considered for appropriateness to our objective. We adopted the PRISMA method for our review. The search for consistency with PoM was filtered through the neurobiological results of superiority illusion studies. RESULTS: Out of a grand total of 139 records, 59 were included in our analysis. Of these, 36 were of uncertain value as to the primacy of mania hypothesis, 22 favoured it, and 1 was contrary, but the latter pooled patients in their manic and depressive phases, so to invalidate possible conclusions about its consistency with regard to PoM. All considered studies were not focused on PoM or superiority illusion, hence most of their results were, as expected, unrelated to the circuitry involved in superiority illusion. A considerable amount of evidence is consistent with the hypothesis, although indirectly so. LIMITATIONS: Only few studies compared manic with depressive phases, with the majority including patients in euthymia. CONCLUSION: It is possible that humans have a natural tendency for elation/optimism and positive self-consideration, that are more akin to mania; the depressive state could be a consequence of frustrated or unsustainable mania. This would be consistent with PoM.

Increased depressive ratings in patients with hepatitis C receiving interferon-alpha-based immunotherapy are related to interferon-alpha-induced changes in the serotonergic system.

There is now evidence that repeated administration of interferon-alpha (IFN-alpha) to patients with chronic active hepatitis and cancers induces depressive symptoms. There is also evidence that induction of the cytokine network modulates the serotonergic system and that major depression is related to activation of the cytokine network and disturbances in the serotonergic metabolism. The aims of this study were to examine the effects of IFN-alpha-based immunotherapy on the development of depressive symptoms in relation to its effects on plasma tryptophan and kynurenine and serum serotonin (5-HT). Eighteen patients affected by chronic active hepatitis C were treated with IFN-alpha (3-6 million units subcutaneously three to six times a week for 6 months) and had measurements of the previous parameters before starting immunotherapy and 2, 4, 16, and 24 weeks later. Severity of depression and anxiety were measured with the Montgomery-Asberg Depression Rating Scale (MADRS) and the Hamilton Rating Scale for Anxiety (HAM-A) scale, respectively. Immunochemotherapy with IFN-alpha (1) significantly increased the MADRS and HAM-A scores and serum kynurenine concentrations and (2) significantly reduced plasma tryptophan and serum 5-HT concentrations. IFN-alpha-based immunotherapy significantly increased the kynurenine per tryptophan quotient, which estimates the activity of indoleamine 2,3-dioxygenase, the major tryptophan-catabolizing enzyme, which is induced by IFNs. There are significant relationships between the IFN-alpha-induced changes in the MADRS score and serum kynurenine (positive) and 5-HT (negative) concentrations. Immunotherapy with IFN-alpha significantly increases the severity of depressive symptoms. The latter is related to changes in the serotonergic system, such as depletion of serum 5-HT and induction of the catabolism of tryptophan to kynurenine. It is suggested that the IFN-alpha-induced changes in the serotonergic turnover could play a role in the development of IFN-alpha-induced depressive symptoms.