Is cerebellar volume related to bipolar disorder?

BACKGROUND: Recent data suggest that cerebellum influences emotion modulation in humans. The findings of cerebellar abnormalities in bipolar disorder (BD) are especially intriguing given the link between the cerebellum emotional and behavioral regulation. The purpose of this study was to evaluate cerebellar volume in patients with euthymic BD type I compared to controls. Moreover, we investigated the possible relationship between cerebellar volume and suicidal behavior. METHODS: Forty-patients with euthymic BD type I, 20 with and 20 without history of suicide attempt, and 22 healthy controls underwent an MRI scan. The participants were interviewed using the Structured Clinical Interview with the DSM-IV axis I (SCID-I), the Hamilton Depression Rating Scale (HDRS), the Young Mania Rating Scale (YMRS) and the Barratt Impulsiveness Scale (BIS-11). RESULTS: Groups were age, gender and years of schooling-matched. The left cerebellum (p=0.02), right cerebellum (p=0.02) and vermis (p<0.01) were significantly smaller in the BD group; however, there were no volumetric differences between the BD subjects with and without suicidal attempt. There was no correlation between cerebellar measurements and clinical variables. LIMITATIONS: The main strength is that our sample consisted of patients with euthymic BD type I without any comorbidities, however, these results cannot establish causality as the cross-sectional nature of the study. CONCLUSIONS: Our findings suggest that the reduction in cerebellar volumes observed in BD type I might be a trait-related characteristic of this disorder. Additional studies with larger samples and subtypes of this heterogeneous disorder are warranted to determine the possible specificity of this cerebellar finding.

Hippocampal volume in borderline personality disorder with and without comorbid posttraumatic stress disorder: a meta-analysis.

BACKGROUND: Several studies have found a reduction in hippocampal volume in borderline personality disorder (BPD) patients. METHODS: In order to investigate the degree to which comorbid posttraumatic stress disorder (PTSD) could account for reduction in hippocampal volume in these patients, we conducted a systematic review and meta-analysis of studies that compared hippocampal volume in BPD patients with and without PTSD relative to healthy controls. RESULTS: Seven articles, involving 124 patients and 147 controls, were included. We found a statistically significant reduction for the left and right hippocampus. Data from the four studies that discriminated BPD patients with and without PTSD indicate that hippocampal volumes were reduced bilaterally in BPD patients with PTSD, relative to healthy controls, but that results were mixed for BPD patients without PTSD, relative to healthy controls. CONCLUSIONS: Results from this meta-analysis suggest that hippocampal volumes are reduced in patients with BPD, relative to healthy controls, but particularly in cases in which patients are diagnosed with comorbid PTSD.