Chinese herbal medicine for schizophrenia
Abstract
Background
Traditional Chinese medicine (TCM) was the main form of treatment in China for psychiatric illnesses until the development of antipsychotic drugs in the 1950's. Antipsychotic drugs have become the primary intervention for schizophrenia, although herbal medicines can still form part of the treatment.
Objectives
To review Chinese herbal medicine, used alone or as part of a TCM approach, for people with schizophrenia and related psychoses.
Search methods
We undertook electronic searches of the Cochrane Schizophrenia Group's register (December 2003), the Traditional Chinese Medical Literature Analysis and Retrieval Database (TCMLARS) (October 2003), Chinese Biomedical Database (CBM) (December 2003), China National Knowledge Infrastructure Database (May 2004), Complementary Medicine Database (AMED) (December 2003). We contacted the Chinese Cochrane Centre, the Cochrane Complementary Medicine Field and first authors of included studies and inspected reference lists for additional studies.
Selection criteria
We included all relevant randomised controlled trials involving people with schizophrenia‐like illnesses, allocated to Chinese herbal medicine, including any Chinese herbs (single or mixture), compared with placebo/no treatment or antipsychotic drugs.
We updated this search July 2012 and added 45 new trials to the awaiting classification section.
Data collection and analysis
We independently extracted data and calculated fixed effects relative risk (RR), the 95% confidence intervals (CI) for homogeneous dichotomous data, and, where appropriate, the number needed to treat (NNT) on an intention‐to‐treat basis. For continuous data, we calculated weighted mean differences (WMD).
Main results
Only one small trial of the seven included studies truly evaluated TCM for schizophrenia. The other trials evaluated Chinese herbs for schizophrenia. We found one study comparing Chinese herbal medicine with antipsychotic drugs. Data for the global state outcome 'no change/worse' favoured people allocated to antipsychotic medication (n=90, RR 1.88 CI 1.2 to 2.9, NNH 4 CI 2 to 12). Six trials compared Chinese herbal medicine in combination with antipsychotic with antipsychotic drugs alone. One trial found global state 'not improved/worse' favoured the herbal medicine/antipsychotic combination (n=123, RR 0.19 CI 0.1 to 0.6, NNT 6 CI 5 to 11). Two studies (n=103) also found short‐term data from the Clinical Global Impression scale favoured the herbal medicine plus antipsychotic group (WMD ‐0.46 CI ‐0.9 to ‐0.1) compared with those given only antipsychotics. Significantly fewer people in the experimental group left the study early compared with those given antipsychotics alone (n=1004, 6 RCTs, RR 0.30 CI 0.16 to 0.58, NNT 21 CI 18 to 35). Reports of constipation were significantly lower in the treatment group compared to those receiving antipsychotics (n=67, 1 RCT, RR 0.03 CI 0.0 to 0.5, NNH 2 CI 2 to 4).
Authors' conclusions
Chinese herbal medicines, given in a Western biomedical context, may be beneficial for people with schizophrenia when combined with antipsychotics. Traditional Chinese medicine is also under‐evaluated, but results from one pioneering study that attempted to evaluate TCM should encourage further trials.
Note: the 45 citations in the awaiting classification section of the review may alter the conclusions of the review once assessed.
PICOs
Plain language summary
Chinese herbal medicine for schizophrenia
Antipsychotic medication is the mainstay of treatment for people with schizophrenia, and although effective, still leaves some people with distressing symptoms and/or disabling adverse effects. Safer and more effective health care interventions are needed.
Traditional Chinese medicine (TCM) has been used to treat mental health disorders, including schizophrenia, for more than 2000 years. Chinese herbs may also have antipsychotic properties when used in a Western biomedical context. In this review we sought and found trials relevant to the effects of both approaches for schizophrenia. Traditional Chinese medicine methodology has been evaluated for schizophrenia, but the one included study was too limited in terms of sample size and study length to guide good practice. However, this pioneering study does show that TCM can be evaluated for its efficacy for people with schizophrenia , and should encourage trialists to undertake further, more comprehensive trials in this area.
The use of Chinese herbs in a Western medicine context, without incorporating TCM methodology, has been evaluated in six trials, although again these are limited by their sample size and study length. The results of these six trials suggest that using Chinese herbs alone for psychotic symptoms may not be indicated, but if used in conjunction with Western antipsychotic drugs, they may be beneficial in terms of mental state, global functioning and decrease of adverse effects. However, further trials are needed before the effects of TCM for people with schizophrenia can be evaluated with any real confidence.
