Results
Eighty-nine percent of youth reported PTSS (i.e., severity
scores>0) at baseline. Hyperarousal was the most prevalent
subtype, followed by re-experiencing, negative affect, and avoidance
(see Table 1 ). There were no significant differences in overall
PTSS (Z= 1.02, p =0.31) or subtypes
(p s>0.1) from baseline to post-intervention. At
baseline, overall PTSS were not significantly associated with volume of
the left or right hippocampus. However, smaller left
(F (2,17)=6.54 p= 0.009, β =-0.77, p =0.004) and
right (F (2,17)=4, p= 0.041, β =-0.65, p =0.019)
hippocampal volumes were associated with more severe re-experiencing
PTSS at baseline. Further, smaller left hippocampal volumes at baseline
were associated with greater reductions in PTSS from baseline to
post-intervention (F (2,17)=4.41 p= 0.031, β =-0.542,p =0.041; Figure 1b,c ). This association was specific to
GM (p =0.14) as compared to WM volume (p =0.47) and was
driven by reductions in both re-experiencing (p =0.011) and
negative affect (p =0.046) subtypes. Left hippocampal volume was
not significantly associated with change in avoidance or hyperarousal
PTSS subtypes (p s>0.5). Right hippocampal volume was
not significantly associated with PTSS change scores, p =0.067.