Magnetic Resonance Imaging Studies in Early Onset Bipolar Disorder: An Updated Review
Over the past 5-10 years, advances in neuroimaging methods and study designs have begun to appear in the literature of early-onset bipolar disorder (onset before 18 years of age). This article contains an updated review of the literature regarding neuroimaging in youths with bipolar disorder (BPD), highlighting important new study designs and techniques. Overall, structural, functional (fMRI) and magnetic resonance spectroscopy (MRS) report consistent abnormalities in regions of the frontal lobe and limbic structures. Functional MRI and MRS studies also frequently report striatal and thalamic abnormalities in early-onset BPD. Future neuroimaging studies in youths with BPD should include longitudinal studies incorporating multimodal neuroimaging techniques.
Available from: Amy S Garrett
- "revious proton magnetic resonance spectroscopy (1H- MRS) studies have suggested the presence of neurometabolic abnormalities in individuals with bipolar disorder (BD), particularly involving myo-inositol (mI) and N-acetylaspartate (NAA) (Terry et al. 2009). mI, a sugar found primarily in glial cells, is thought to be involved in myelin sheet and cell membrane synthesis (Haris et al. 2010) and concentrations of mI levels may correlate with myelin turnover. "
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ABSTRACT: Mood stabilizers have been reported to affect brain concentrations of myo-inositol (mI) and N-acetylaspartate (NAA). We examined the effects of quetiapine (QUET), an atypical antipsychotic, on these neurochemicals, and potential predictors of response to QUET in adolescents with bipolar depression.
Twenty-six adolescents with bipolar depression participated in an 8-week placebo-controlled trial of QUET monotherapy. Subjects were scanned at baseline and after 8 weeks with proton magnetic resonance spectroscopy (1H-MRS) at 3T and 4T at two sites, with 8 cm(3) voxels placed in the right and left dorsolateral prefrontal cortex (DLPFC) and anterior cingulate cortex (ACC). LCModel was used to calculate absolute concentrations of NAA and mI.
Twenty-six subjects had pre- and posttreatment scans (mean age=15.6 years, 9 boys). Of these subjects, 5 out of 16 subjects receiving QUET and 5 out of 10 receiving placebo (PBO) were responders (50% decrease in Children's Depression Rating Scale [CDRS] score). Although baseline ACC mI did not predict responder status, responders had significantly lower posttreatment ACC mI values than did nonresponders (3.27±.71 vs. 4.23±.70; p=0.004). There were no significant differences in the changes in ACC and DLPFC NAA levels in the QUET group compared with the PBO group (ACC: -0.55±1.3 vs.+0.25±1.5, p=0.23; right-DLPFC: -0.55±1.3 vs. 0.33±0.89, p=0.13; left-DLPFC: -0.04±0.91 vs.+0.29±0.61, p=0.41).
We found that posttreatment, not baseline, ACC mI levels were associated with response to QUET in adolescents with bipolar depression. There were no differences in NAA concentration changes between the QUET and PBO groups. Larger studies including different brain regions would help to clarify the effects of QUET on neurochemistry in patients with bipolar disorder.
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ABSTRACT: A variety of psychiatric disorders including depression have been reported in patients suffering from incontinence. It is uncertain if the association between incontinence and depression is causal or is related to a third common factor. We report the case of a 48-year-old man who presented with incontinence of urine and faeces along with a severe depressive episode. No organic cause could be identified for the incontinence. The depressive symptoms as well as the incontinence resolved with treatment with reboxetine and aripiprazole. However, the patient developed a manic episode. This case supports the hypothesis that incontinence and depression may share a common pathogenesis. The authors review the literature to investigate this linkage. The combination of aripiprazole and reboxetine should be used cautiously when treating first episode depression as it can induce a manic switch. Previous reports of manic switch with aripiprazole and reboxetine are reviewed.
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