Anomalous prefrontal-limbic activation and connectivity in youth at high-risk for bipolar disorder.

OBJECTIVE: Abnormal prefrontal-limbic brain activation in response to facial expressions has been reported in pediatric bipolar disorder (BD). However, it is less clear whether these abnormalities exist prior to onset of mania, thus representing a biomarker predicting development of BD. METHODS: We examined brain activation in 50 youth at high risk for BD (HR-BD), compared with 29 age- and gender-matched healthy control (HC) subjects. HR-BD was defined as having a parent with BD, as well as current mood or attentiondeficit/ hyperactivity disorder (ADHD) symptoms, or a history of at least one depressive episode. FMRI data were collected during an implicit emotion perception task using facial expression stimuli. Activation to fearful faces versus calm faces was compared between HR-BD and HC groups, including analyses of functional connectivity, and comparison of allele subgroups of the serotonin transporter (5-HTTLPR) gene. RESULTS: While viewing fearful versus calm faces, HR-BD youth had significantly greater activation than HC youth in the right amygdala, ventrolateral prefrontal cortex (VLPFC), superior frontal cortex, cerebellum, and lingual gyrus. HR-BD youth, relative to HC youth, had greater functional connectivity between the right amygdala and the VLPFC as well as visual cortical regions Within the HR-BD group, youth with the s-allele had a trend for greater activation in the right amygdala and subgenual cingulate cortex CONCLUSIONS: Similar to youth with BD, youth at high risk for BD have greater activation than healthy controls in the amygdala and ventrolateral prefrontal cortex in response to fearful faces, as well greater functional connectivity between these regions. HR-BD youth with the s-allele of the 5-HTTLPR gene may be at greatest risk for developing BD.

Socio-emotional processing and functioning of youth at high risk for bipolar disorder.

BACKGROUND: The goal of this study was to investigate differences in socio-emotional processing and functioning in children and adolescents at high risk for bipolar disorder (BD) and healthy control participants. METHODS: Children and adolescents with a parent with bipolar disorder, who had mood dysregulation but not fully syndromal BD (high risk, HR, n=24), were compared to participants with no personal or family history of psychopathology (healthy control, HC, n=27) across several neuropsychological domains. Social reciprocity was measured by the Social Responsiveness Scale, theory of mind was measured by use of the NEPSY, and affect recognition was measured by the NEPSY and the Diagnostic Test of Nonverbal Accuracy 2 (DANVA). RESULTS: The HR group demonstrated significant impairment in social reciprocity, including impairments in social awareness, social cognition, social communication, social motivation, and autistic mannerisms. There were no significant group differences in performance on theory of mind or affect recognition tasks. LIMITATIONS: Lack of impairment in tasks associated with theory of mind or affect recognition indicate that social functioning difficulties are not likely due to impairments in these areas, or that the measures employed were not sufficiently sensitive to detect group differences. CONCLUSIONS: Youth at high risk for BD demonstrated impairments in numerous social domains, which may be due to innate differences in brain development governing socio-emotional functioning or may be due to disruptions in normal development caused by mood regulation difficulties.