5. Discussion
PTSD, anxiety
The purpose of the study was to investigate GABA concentration in the dorsal ACC in adults with diagnosed GAD and to assess whether these levels were modified by Kava. A significant difference in GABA concentration was observed in the Kava group at eight weeks compared with the placebo group, showing a reduction in GABA concentration levels in the ROI.The study operated as a ‘proof of concept’ investigation, both in establishing the measurement of GABA in GAD and in evidencing neural mechanisms amenable to Kava. It addressed these aims through assessing GAD symptoms and biological outcomes before examining the role of Kava on both GABA levels and anxiety symptoms.This study found that baseline anxiety levels were positively associated with GABA levels in the dACC but that a daily dose of 240 mg Despite these findings, results suggest that Kava modifies brain GABA levels, as GABA level reductions were observed in the Kava group in the dACC region compared with the placebo group. This reduction could represent a ‘normalisation’ in GABA levels, which is reflected in the handful of studies in the area that show that raised GABA is linked to anxiety levels in healthy samples, as well as elevations in PTSD compared with healthy controls [Given the bioactive constituent profile of the extract used in this study and the GABAergic mechanisms exerted by kavain, dihydrokavain, and methysticin in particular, it is feasible that the observed effects have occurred via enhancement to particular GABA-A receptor subtypes in the ROI through direct ligand-binding enhancement or indirectly via reductions to thromboxane A (2), which antagonises GABA-A receptor functions. It is also likely that modulations have occurred elsewhere in the shunt, such as the excitatory glutaminergic corollary through calcium ion channel blockades via the MAO-B receptor substrate, and there is increasing evidence of glutaminergic modulation in preclinical research [