Lithium-derived effects on ER
RECRUITMENT, CORTEX
During reappraisal of negative images, compared to maintain, lithium exerted a number of effects on the fronto-parietal network: (1) decreased activation in the left anterior prefrontal cortex, right superior frontal gyrus, and the left AG, and (2) decreased the connectivity between the right vlPFC and other regions of the fronto-limbic cortex, including the anterior PFC, ACC, caudate, and insula. The anterior prefrontal cortex is a high-level integrative area receiving information from somatosensory networks (Peng et al. BD has been associated with reduced recruitment of the regulatory fronto-parietal network during cognitive reappraisal (Zhang et al. During negative picture block presentation (collapsing across conditions), further fronto-limbic effects were seen. That is, participants in the lithium group, compared to those in the placebo group, had a significantly greater anticorrelation between the left amygdala and bilateral prefrontal regions. This anticorrelated pattern between prefrontal and limbic regions is expected when successfully employing ER strategies (Kanske et al. Altogether, the described effects of lithium on fronto-parietal activity and connectivity suggest that, when instructed to engage in ER strategies, prefrontal activation is reduced, potentially reflecting a lower need of regulatory efforts over limbic regions due to lithium treatment or reduced difference between the regulatory processes applied across different conditions. Consistent with this, there was a greater anti-correlation between the amygdala and PFC during viewing of negative pictures whether this was during the maintain or reappraise condition.Further effects of the mood stabiliser on reappraisal and emotional processing of negative images can be seen on superior temporal structures. Accordingly, during reappraisal, as compared to maintain, those in the lithium group showed increased activation in the right superior temporal gyrus, and a significantly greater connectivity between the MTG and the left middle frontal gyrus. During negative picture blocks, those in the lithium group had greater correlated activation between the right MTG and bilateral medial PFC, including the paracingulate cortex and the dmPFC. Involvement of the superior and the middle temporal gyrus in emotional downregulation through cognitive reappraisal has previously been reported (Kohn et al. 