Figure 2.

Varenicline treatment effects on PPI and P50 sensory gating. Moderate dose varenicline significantly reduced startle reactivity as measured by the acoustic startle response amplitude in schizophrenia patients compared with placebo (combined smokers and nonsmokers), significant only in week 8 (A); but did not significantly changed %PPI to the startle response (combined smokers and nonsmokers) (B). P50 gating (S2/S1 ratio) was significantly increased (reduced ratio) by moderate dose varenicline compared with placebo; the effect was significant at week 8 in the entire sample (C) and in the nonsmoker subgroup (D) but not significant in the smoker subgroup (E) although the varenicline effect followed the same pattern in both groups. Note that reduced S2/S1 ratio implies improved gating function. P50 average evoked potential amplitude was not significantly different between varenicline and placebo for response to the first click S1 in the entire sample (F) but was significantly reduced by varenicline compared with placebo for response to the second click S2 (G) (combined smokers and nonsmokers). Numbers of subjects (n) in parentheses are subjects with usable data available at baseline (same in all figures below). Numbers of subjects may vary in subsequent time points. Please refer to Figure 1. ALL: smokers and nonsmokers. NSK: nonsmokers. SK: smokers.