Efficacy and Safety of Yokukansan in Treatment-Resistant Schizophrenia: A Randomized, Multicenter, Double-Blind, Placebo-Controlled Trial

Abstract EN

Objectives.

We aimed at evaluating both the efficacy and safety of TJ-54 (Yokukansan) in patients with treatment-resistant schizophrenia.

This randomized, multicenter, double-blind, placebo-controlled study was conducted.

Methods.

One hundred and twenty antipsychotic-treated inpatients were included.

Patients were randomized to adjuvant treatment with TJ-54 or placebo.

During a 4-week follow-up, psychopathology was assessed using the Positive and Negative Syndrome Scale (PANSS).

Results.

TJ-54 showed a tendency of being superior to placebo in reduction total, positive, and general PANSS scores in treatment-resistant schizophrenia, but the difference was not statistically significant in both per-protocol set (PPS) and intention-to-treat (ITT).

However, in PPS analysis, compared to the placebo group, the TJ-54 group showed statistically significant improvements in the individual PANSS subscale scores for lack of spontaneity and flow of conversation (TJ-54: − 0.23 ± 0.08 ; placebo: − 0.03 ± 0.08 , P < 0.018 ), tension (TJ-54: − 0.42 ± 0.09 ; placebo: − 0.18 ± 0.09 , P < 0.045 ), and poor impulse control (TJ-54: − 0.39 ± 0.10 ; placebo: − 0.07 ± 0.10 , P < 0.037 ).

Conclusions.

The results of the present study indicate that TJ-54 showed a tendency of being superior to placebo in reduction PANSS scores in treatment-resistant schizophrenia, but the difference was not statistically significant.

However, compared to the placebo group, TJ-54 group showed statistically significant improvements in the individual PANSS subscale scores.