Figure 1.

Effect of prazosin on individual PTSD symptoms as described by CAPS for DSM-IV individual item scores (range: 0–8). Change in CAPS item scores over 15 weeks, as calculated by a linear mixed effects model, are given by treatment group with 95% confidence intervals, adjusted for gender and use of antidepressant medications. The difference between the effect of prazosin and the effect of placebo, termed Improvement Beyond Placebo (IBP), is presented in the final column with 95% confidence intervals. Items in the dark red box represent those with an IBP > 1, all of which were also items for which the effect of prazosin was statistically significantly different from that of placebo with a p < .05, uncorrected for multiple comparisons; this group is termed the “highly prazosin responsive group” in text.