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Objective: Perimenopause is associated with an increased risk of developing a major depressive (MD) episode. A significant number of women develop their first MD episode during perimenopause, suggesting a unique pathophysiology of perimenopausal (PM) depression. Previous research has shown that depression is associated with decreased gamma-aminobutyric acid (GABA) levels in the medial prefrontal cortex (MPFC) of MD patients. The objective of this study was to compare MPFC GABA+ levels in healthy reproductive-aged (RD) and PM women., Methods: A total of 18 healthy PM and 20 RD women were included in the study. MPFC GABA+ levels, which include homocarnosine and macromolecules, were measured via magnetic resonance spectroscopy using a 3 Tesla magnet. MPFC GABA+ levels were referenced to creatine + phosphocreatine (Cr+PCr). Absence of current or past psychiatric diagnosis was confirmed via a structured interview. RD participants were scanned during the early follicular phase of the menstrual cycle. PM women were scanned outside of ovulatory cycles., Results: Mean MPFC GABA+ concentrations (relative to Cr+PCr) were decreased in the PM group compared with the RD group (PM mean = 0.08 ± 0.02, RD mean = 0.09 ± 0.02, t = -2.03, df = 36, P = .05) even after correcting for in percentage in gray matter (GM). Because PM women were inherently older than RD women (aged 48.8 ± 3.55 and 31.5 ± 9.66 years, respectively), the age difference between the 2 groups was statistically significant (P < .001). When age was treated as an independent covariate and included in the model, the difference in GABA+ between PM and RD women was no longer significant (P = .092)., Conclusion: Perimenopause is associated with decreased MPFC GABA+/Cr+PCr levels, which may contribute to the increased risk of experiencing a MD episode during PM., (© The Author(s) 2022. Published by Oxford University Press on behalf of CINP.)

An optimized single-shot proton double-quantum (DQ) filter for the quantification of gamma-aminobutyric acid (GABA) levels in human brain is reported. It is demonstrated that creation of DQ coherences following dual-resonance-selective refocusing gives a theoretical editing efficiency of 50% for the detection of the GABA resonance at 3.01 ppm. The sequence times are optimized with both numerical and experimental analyses of the editing performance, giving an experimental editing efficiency of 42%. It is acknowledged that homocarnosine is partially coedited, leading to a 20% contribution to the edited signal; however, macromolecule contamination is negligible in vivo under these experimental conditions. The GABA concentration in human prefrontal cortex is estimated to be 0.8 +/- 0.1 micromol/g (mean +/- SD, n = 6), with reference to the internal standard creatine at 9 micromol/g., (2005 Wiley-Liss, Inc)

BACKGROUND: It has been suggested that lithium increases choline concentrations, although previous human studies examining this possibility using 1H magnetic resonance spectroscopy (1H MRS) have had mixed results: some found increases while most found no differences. METHODS: The present study utilized 1H MRS, in a 3 T scanner to examine the effects of both lithium and sodium valproate upon choline concentrations in treated euthymic bipolar patients utilizing two different methodologies. In the first part of the study healthy controls (n = 18) were compared with euthymic Bipolar Disorder patients (Type I and Type II) who were taking either lithium (n = 14) or sodium valproate (n = 11), and temporal lobe choline/creatine (Cho/Cr) ratios were determined. In the second part we examined a separate group of euthymic Bipolar Disorder Type I patients taking sodium valproate (n = 9) and compared these to controls (n = 11). Here we measured the absolute concentrations of choline in both temporal and frontal lobes. RESULTS: The results from the first part of the study showed that bipolar patients chronically treated with both lithium and sodium valproate had significantly reduced temporal lobe Cho/Cr ratios. In contrast, in the second part of the study, there were no effects of sodium valproate on either absolute choline concentrations or on Cho/Cr ratios in either temporal or frontal lobes. CONCLUSIONS: These findings suggest that measuring Cho/Cr ratios may not accurately reflect brain choline concentrations. In addition, the results do not support previous suggestions that either lithium or valproate increases choline concentrations in bipolar patients.