Effectiveness of horticultural therapy: A systematic review of randomized controlled trials

•This is the first systematic review of the effectiveness of horticultural therapy (HT) based on randomized controlled trials.•Our study is unique because it summarized the evidence for each target disease according to the International Classification of Diseases-10.•There was insufficient evidence in the studies of HT due to poor methodological and reporting quality and heterogeneity.•HT may be an effective treatment for mental and behavioral disorders such as dementia, schizophrenia, depression, and terminal-care for cancer.

SummaryAimTo summarize the evidence from randomized controlled trials (RCTs) on the effects of horticultural therapy (HT).MethodsStudies were eligible if they were RCTs. Studies included one treatment group in which HT was applied. We searched the following databases from 1990 up to August 20, 2013: MEDLINE via PubMed, CINAHL, Web of Science, Ichushi-Web, GHL, WPRIM, and PsyclNFO. We also searched all Cochrane Database and Campbell Systematic Reviews up to September 20, 2013.ResultsFour studies met all inclusion criteria. The language of all eligible publications was English and Korean. Target diseases and/or symptoms were dementia, severe mental illness such as schizophrenia, bipolar disorder, and major depression, frail elderly in nursing home, and hemiplegic patients after stroke. These studies showed significant effectiveness in one or more outcomes for mental health and behavior. However, our review especially detected omissions of the following descriptions: method used to generate randomization, concealment, blinding, and intention-to-treat analysis. In addition, the results of this study suggested that the RCTs conducted have been of relatively low quality.ConclusionAlthough there was insufficient evidence in the studies of HT due to poor methodological and reporting quality and heterogeneity, HT may be an effective treatment for mental and behavioral disorders such as dementia, schizophrenia, depression, and terminal-care for cancer.