East Asian herbal medicine may have therapeutic potential in schizophrenia

Use of East Asian herbal medicine as an adjunct to antipsychotics may help improve symptoms and reduce adverse events in patients with schizophrenia, according to a meta-analysis.

Researchers searched multiple online databases for randomized controlled trials evaluating the effectiveness and safety of East Asian herbal medicine combined with antipsychotics vs antipsychotics alone. Risk of bias was assessed using the Cochrane Risk of Bias tool, while certainty of evidence was evaluated using GRADE.

The primary outcome was the overall symptom scores, measured using the Positive and Negative Syndrome Scale (PANSS) or the Brief Psychiatric Rating Scale (BPRS). Secondary outcomes included adverse events, negative and positive symptom scores, response rates, social function, quality of life, recurrence, and adherence.

A total of 270 studies involving 26,053 participants were included in the meta-analysis. Pooled data showed that compared with standard-dose antipsychotics alone, the use of East Asian herbal medicine as an adjunct to standard-dose antipsychotics was associated with improved overall symptom (standardized mean difference [SMD ], −1.38, 95 percent confidence interval [CI], − 1.60 to −1.17; 181 studies, n=18,56; low-certainty evidence) and reduced adverse events (risk ratio [RR], 0.56, 95 percent CI, 0.51–0.62; 92 studies, n=8,983; low-certainty evidence).

Similarly, combining East Asian herbal medicine with low-dose antipsychotics resulted in symptom improvement (SMD, −0.92, 95 percent CI, −1.54 to −0.29; 25 studies, n=1,907; low-certainty evidence) and fewer adverse events (RR, 0.44, 95 percent CI, 0.34–0.58; 6 studies, n=450; low-certainty evidence).

These findings should be interpreted with caution, given the potential publication bias, and underscore the need for high-quality studies.