Table 4.

Means and standard deviations of volumes and metabolite in subjects positive (P+) or negative (P-) for PTSD and with (A+) or without (A+) alcohol abuse

Group	Hippocampus volumea	Frontal WM volumea	Hippocampus NAA/Crb	Anterior cingulate NAAc
P+A+	0.413±0.031	19.0±1.9	1.64±0.21	1.67±0.34
P+A-	0.413±0.051	18.7±1.8	1.70±0.18	1.71±0.32
P-A+	0.412±0.045	18.5±1.3	1.84±0.26	1.91±0.37
P-A-	0.428±0.046	18.7±2.4	1.80±0.17	1.93±0.33

^aTotal (left and right) volume in percent of intracranial volume.

^bLeft and right averaged.

^cConcentration in arbitrary units.