Table 1.

MRI brain volumes (ml) for severe PTSD subjects (CAPS > 65).

	PTSD (n = 24)		Non-PTSD (n = 46)		Two-factor ANOVA
	Exposed (n = 12)	Unexposed (n = 12)	Exposed (n = 23)	Unexposed (n = 23)	Diagnosis		Exposure		Interaction
					F1,66	P	F1,66	P	F1,66	P
Total brain volume	1221 (108)	1239 (125)	1258 (106)	1246 (112)	0.61	0.44	0.01	0.92	0.28	0.60
Total hippocampus	6.66 (0.83)	6.75 (0.90)	7.41 (0.93)	7.25 (0.69)	8.73	0.004	0.03	0.87	0.34	0.56
Right hippocampus	3.32 (0.59)	3.26 (0.39)	3.76 (0.54)	3.61 (0.48)	9.63	0.003	0.62	0.43	0.13	0.72
Left hippocampus	3.34 (0.46)	3.49 (0.57)	3.65 (0.50)	3.63 (0.45)	3.35	0.07	0.29	0.59	0.40	0.53
Total amygdala	4.65 (0.87)	4.53 (1.24)	4.45 (0.67)	4.61 (0.86)	0.07	0.80	0.01	0.92	0.40	0.53
Right amygdala	2.37 (0.52)	2.58 (0.64)	2.34 (0.39)	2.46 (0.48)	0.37	0.54	1.76	0.19	0.12	0.73
Left amygdala	2.27 (0.49)	1.95 (0.68)	2.11 (0.47)	2.15 (0.58)	0.02	0.90	1.06	0.31	1.76	0.19

Data given as mean (s.d.).

Follow-up t-tests:

Total hippocampus: ExP+ versus ExP−, t₃₃ = 2.32, P = 0.03; UxP+ versus UxP−, t₃₃ = 1.83, P = 0.08; ExP+ versus UxP+, t₁₁ = 0.38, P = 0.71; ExP− versus UxP−, t₂₂ = 1.11, P = 0.28. Right hippocampus: ExP+ versus ExP−, t₃₃ = 2.23, P = 0.03; UxP+ versus UxP−, t₃₃ = 2.17, P = 0.04; ExP+ versus UxP+, t₁₁ = 0.30, P = 0.77; ExP− versus UxP−, t₂₂ = 1.42, P = 0.17. Left hippocampus: ExP+ versus ExP−, t₃₃ = 1.74, P = 0.09; UxP+ versus UxP−, t₃₃ = 0.85, P = 0.40; ExP+ versus UxP+, t₁₁ = 1.31, P = 0.22; ExP− versus UxP−, t₂₂ = 0.09, P = 0.93.