A number of MRS studies, however, report effects on Glu contradictory to the model, regardless of the timing of data acquisition relative to heavy drinking. For example, a trend towards lower Glu in frontal white matter was observed in heavy drinkers compared to light drinkers, where heavier drinking and greater loss of control over drinking were associated with lower Glu levels (Ende et al., 2013). A negative correlation was also reported in the anterior cingulate between basal Glu levels and the number of drinking days in the past 2 week (i.e., more drinking days, less Glu) (Cheng et al., 2018). Similarly, number of heavy drinking days in the 14 days preceding observation was significantly inversely associated with anterior cingulate Glu concentrations (Prisciandaro et al., 2016).
