Brady Roscoe O, McCarthy Julie M, Prescot Andrew P, Jensen J Eric, Cooper Alissa J, Cohen Bruce M, Renshaw Perry F, Ongür Dost
Department of Psychiatry, Beth-Israel Deaconess Hospital, Salt Lake City, UT, USA; Department of Psychiatry, Harvard Medical School, Salt Lake City, UT, USA; Department of Psychiatry, Massachusetts Mental Health Center, Boston, USA; Psychotic Disorders Division, McLean Hospital, Belmont, MA, USA.
Bipolar Disord. 2013 Jun;15(4):434-9. doi: 10.1111/bdi.12074. Epub 2013 May 2.
Gamma-aminobutyric acid (GABA) abnormalities have been implicated in bipolar disorder. However, due to discrepant studies measuring postmortem, cerebrospinal fluid, plasma, and in vivo brain levels of GABA, the nature of these abnormalities is unclear. Using proton magnetic resonance spectroscopy, we investigated tissue levels of GABA in the anterior cingulate cortex and parieto-occipital cortex of participants with bipolar disorder and healthy controls.
Fourteen stably medicated euthymic outpatients with bipolar disorder type I (mean age 32.6 years, eight male) and 14 healthy control participants (mean age 36.9 years, 10 male) completed a proton magnetic resonance spectroscopy scan at 4-Tesla after providing informed consent. We collected data from two 16.7-mL voxels using MEGAPRESS, and they were analyzed using LCModel.
GABA/creatine ratios were elevated in bipolar disorder participants compared to healthy controls [F(1,21) = 4.4, p = 0.048] in the anterior cingulate cortex (25.1% elevation) and the parieto-occipital cortex (14.6% elevation). Bipolar disorder participants not taking GABA-modulating medications demonstrated greater GABA/creatine elevations than patients taking GABA-modulating medications.
We found higher GABA/creatine levels in euthymic bipolar disorder outpatients compared to healthy controls, and the extent of this elevation may be affected by the use of GABA-modulating medications. Our findings suggest that elevated brain GABA levels in bipolar disorder may be associated with GABAergic dysfunction and that GABA-modulating medications reduce GABA levels in this condition.
γ-氨基丁酸（GABA）异常与双相情感障碍有关。然而，由于在测量死后、脑脊液、血浆和体内脑内GABA水平的研究中结果存在差异，这些异常的本质尚不清楚。我们使用质子磁共振波谱技术，研究了双相情感障碍患者和健康对照者前扣带回皮质和顶枕叶皮质中GABA的组织水平。
14名稳定服用药物且处于心境正常期的I型双相情感障碍门诊患者（平均年龄32.6岁，8名男性）和14名健康对照者（平均年龄36.9岁，10名男性）在签署知情同意书后，接受了4特斯拉的质子磁共振波谱扫描。我们使用MEGAPRESS从两个16.7毫升的体素中收集数据，并使用LCModel进行分析。
与健康对照者相比，双相情感障碍患者前扣带回皮质（升高25.1%）和顶枕叶皮质（升高14.6%）的GABA/肌酸比值升高[F(1,21) = 4.4，p = 0.048]。未服用GABA调节药物的双相情感障碍患者比服用GABA调节药物的患者GABA/肌酸升高幅度更大。
我们发现，与健康对照者相比，处于心境正常期的双相情感障碍门诊患者的GABA/肌酸水平更高，这种升高的程度可能受GABA调节药物使用的影响。我们的研究结果表明，双相情感障碍患者脑内GABA水平升高可能与GABA能功能障碍有关，并且GABA调节药物在这种情况下会降低GABA水平。
