Abstract
ABSTRACTBackgroundAbnormalities of gamma-aminobutyric acid-ergic (GABAegic) systems may play an important role in psychosis spectrum and mood disorders. Proton magnetic resonance spectroscopy allows for non-invasive in vivo quantification of GABA; however, studies of GABA in psychosis have yielded inconsistent findings. This may stem from grouping together disparate voxels from functionally heterogeneous regions.MethodsWe searched the PubMed database for magnetic resonance spectroscopy studies of medial frontal cortex (MFC) GABA in patients with psychosis, bipolar disorder, depression, and individuals meeting ultra-high risk for psychosis criteria. Voxel placements were classified as rostral-, rostral-mid-, mid-, or posterior MFC, and random effects meta-analyses conducted for each group, for each MFC sub-region.ResultsOf 341 screened articles, 23 studies of psychosis (752 patients,856 controls), 6 studies of bipolar disorder (129 patients, 94 controls), 20 studies of depression (463 cases, 449 controls) and 7 studies of ultra-high risk (229 patients, 232 controls) met inclusion criteria. Meta-analysis revealed lower mid-(SMD = -0.28, 95% confidence interval [CI] = -0.48 to -0.07, p < .01) and posterior (SMD = -0.29, 95% CI = -0.49 to -0.09, p <.01) MFC GABA in psychosis, and increased rostral GABA in bipolar disorder (SMD = 0.76, 95% CI = 0.25 to 1.25, p < .01). In depression, reduced rostral MFC GABA (SMD = -0.36, 95% CI = -0.64 to -0.08, p = .01) did not survive correction for multiple comparisons.ConclusionsThese results substantiate the relevance in the ethology of psychosis spectrum and mood disorders and underline the importance of voxel placement.
Publisher
Cold Spring Harbor Laboratory