a. Total PANSS subscale scores for all 19 participants tested after placebo (white) and ketamine (gray) administration. b. PANSS component scores for all positive symptom (P1–P7) and one general symptom dimension (G9). Analysis revealed a main effect of drug (F1,19 = 36.4, p=0.0001), symptom dimension (F5,92 = 8.4, p=0.009) and a significant drug by symptom dimension interaction. Post-hoc tests revealed that hallucinations were the most common symptom, with hallucination scores exceeding those of the other PANSS items. Error bars = 1 SEM.