Hippocampal volume and memory impairment after electroconvulsive therapy in patients with depression.

OBJECTIVE: Patients hesitate to consent to electroconvulsive therapy (ECT) because of the fear of memory impairment. The mechanisms underlying this impairment are unclear, but several observations suggest hippocampal alterations may be involved. We investigated whether ECT-induced change in hippocampal volume correlates with memory impairment. METHODS: Using a 3 T MRI scanner, we acquired brain images and assessed cognitive performance in 22 severely depressed patients at three time points: (1) before ECT series, (2) within one week after the series, and (3) at six-month follow-up. The hippocampus was segmented into subregions using FreeSurfer. The dentate gyri (DG) were the primary regions of interest (ROIs) and major hippocampal subregions secondary ROIs. Cognitive performance was assessed using the Screen for Cognitive Impairment in Psychiatry and verbal memory using the Verbal Learning subtest. The linear mixed model and the repeated-measures correlation were used for statistical analyses. RESULTS: ECT induced an increase in the right and left DG volume with co-occurring worsening in verbal memory, and these changes were within-patients negatively correlated (right DG, rrm  = -0.85, df = 18, p = 0.0000002; left DG, rrm  = -0.58, df = 18, p = 0.008). At a six-month follow-up, the volume of both DG decreased with a co-occurring improvement in verbal memory, and these changes were negatively correlated in the right DG (rrm  = -0.64, df = 15, p = 0.005). Volume increases in 14 secondary ROIs were also negatively correlated with memory impairment. CONCLUSION: ECT-related transient increases in the volume of major hippocampal subregions within-patients are associated with memory impairment. Hippocampal alterations following ECT should be the focus in searching for causes of the cognitive side effects.

Impaired down-regulation of negative emotion in self-referent social situations in bipolar disorder: A pilot study of a novel experimental paradigm.

Emotion dysregulation is a core feature of bipolar disorder (BD) that persists into periods of remission. Neuroimaging studies show aberrant neural responses during emotion regulation (ER) in patients with BD relative to healthy controls, but behavioural evidence for ER deficits is sparse and conflicting. This study aimed to explore ER in BD using a novel, personally relevant experimental paradigm. Twenty patients with BD and 20 patients with unipolar disorder (UD), in full or partial remission, and 20 healthy controls were given a novel computerised test. Participants were instructed to react naturally or dampen their emotional response to positive and negative social scenarios and associated self-beliefs. They were also given an established experimental task for comparison, involving reappraisal of negative affective picture stimuli, as well as a questionnaire of habitual ER strategies. BD patients showed reduced ability to down-regulate emotional responses in negative, but not positive, social scenarios relative to healthy controls and UD patients. In contrast, there were no between-group differences in the established ER task or in self-reported habitual reappraisal strategies. Findings highlight the novel social scenario paradigm as a sensitive test for detection of ER difficulties in BD.

Optimising screening for cognitive dysfunction in bipolar disorder: Validation and evaluation of objective and subjective tools.

INTRODUCTION: Cognitive impairment is common in bipolar disorder and contributes to socio-occupational difficulties. The objective was to validate and evaluate instruments to screen for and monitor cognitive impairments, and improve the understanding of the association between cognitive measures and socio-occupational capacity. METHODS: Patients with bipolar disorder in partial or full remission (n=84) and healthy controls (n=68) were assessed with the Screen for Cognitive Impairment in Psychiatry (SCIP), Cognitive Complaints in Bipolar Disorder Rating Scale (COBRA), and established neuropsychological tests and subjective rating scales. Socio-occupational function and affective symptoms were evaluated with the Functional Assessment Short Test, and the Hamilton Depression Rating Scale 17-items and Young Mania Rating Scale, respectively. Concurrent validity of the SCIP and COBRA were assessed by correlation with established objective and subjective cognitive measures, and decision validity was determined with Receiver-Operating-Characteristic analyses. Correlations and linear regression analyses were conducted to determine the associations between objective and subjective cognitive impairment, and socio-occupational difficulties. RESULTS: The SCIP and COBRA correlated strongly with established objective and subjective cognitive measures, respectively. The SCIP yielded higher sensitivity and specificity for detection of cognitive dysfunction than the COBRA or a combined SCIP-COBRA measure. Correlations between objective and subjective cognitive impairment were weak but both were associated with socio-occupational difficulties. LIMITATIONS: Influence of ageing was not investigated. CONCLUSIONS: The SCIP and COBRA are valid for detection of objective and subjective cognitive impairment in bipolar disorder. Screening for cognitive dysfunction should be conducted with an objective measure like the SCIP.