Fig. 4: Combined treatment with aripiprazole and ketamine suppresses ketamine-induced dissociation, but not its antidepressant effect in depressed patients.
a Study schedule and the procedure for assessment of the effects of ketamine, aripiprazole plus ketamine, and brexpiprazole plus ketamine. b Changes in dissociative symptoms as assessed with the CADSS after administration of ketamine (One-tailed Wilcoxon matched-pairs signed rank test, *P < 0.05, P < 0.1). The blue shade indicates the normal range, < 4. c Percentage of dissociation-positive cases (post-ketamine CADSS > 4 and CADSS change >0) and mean plasma concentrations of antipsychotics at each dosing time (n = 7, except n = 8 for percentage of dissociation-positive cases at placebo treatment). d The number of dissociation-positive cases when the concentration of aripiprazole in plasma was < or ≥ 20 ng/mL in sessions one to four (n = 29 cases, Fisher’s exact test, **P < 0.01). e Changes in the depression symptoms assessed with the MADRS throughout treatment (n = 7, one-way repeated-measures ANOVA, treatment, F2,15 = 15.00, P = 0.0001; Dunnett’s multiple comparisons test: *P < 0.05, **P < 0.01, vs before treatment with placebo plus ketamine). MADRS: Montgomery–Åsberg depression rating scale, CADSS: Clinician-Administered Dissociative States Scale.
