Horticultural therapy for schizophrenia
Editorial Group: Cochrane Schizophrenia Group
Published Online: 19 MAY 2014
Assessed as up-to-date: 3 SEP 2013
Copyright © 2014 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
How to Cite
Liu Y, Bo L, Sampson S, Roberts S, Zhang G, Wu W. Horticultural therapy for schizophrenia. Cochrane Database of Systematic Reviews 2014, Issue 5. Art. No.: CD009413. DOI: 10.1002/14651858.CD009413.pub2.
- Publication Status: Edited (no change to conclusions)
- Published Online: 19 MAY 2014
Horticultural therapy is defined as the process of utilising fruits, vegetables, flowers and plants facilitated by a trained therapist or healthcare provider, to achieve specific treatment goals or to simply improve a person's well-being. It can be used for therapy or rehabilitation programs for cognitive, physical, social, emotional, and recreational benefits, thus improving the person's body, mind and spirit. Between 5% to 15% of people with schizophrenia continue to experience symptoms in spite of medication, and may also develop undesirable adverse effects, horticultural therapy may be of value for these people.
To evaluate the effects of horticultural therapy for people with schizophrenia or schizophrenia-like illnesses compared with standard care or other additional psychosocial interventions.
We searched the Cochrane Schizophrenia Group Trials Register (Janurary 2013) and supplemented this by contacting relevant study authors, and manually searching reference lists.
We included one randomised controlled trial (RCT) comparing horticultural therapy plus standard care with standard care alone for people with schizophrenia.
Data collection and analysis
We reliably selected, quality assessed and extracted data. For continuous outcomes, we calculated a mean difference (MD) and for binary outcomes we calculated risk ratio (RR), both with 95% confidence intervals (CI). We assessed risk of bias and created a 'Summary of findings' table using the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) approach.
We included one single blind study (total n = 24). The overall risk of bias in the study was considered to be unclear although the randomisation was adequate. It compared a package of horticultural therapy which consisted of one hour per day of horticultural activity plus standard care with standard care alone over two weeks (10 consecutive days) with no long-term follow-up. Only two people were lost to follow-up in the study, both in the horticultural therapy group (1 RCT n = 24,RR 5.00 95% CI 0.27 to 94.34, very low quality evidence). There was no clear evidence of a difference in Personal Wellbeing Index (PWI-C) change scores between groups, however confidence intervals were wide (1 RCT n = 22, MD -0.90 95% CI -10.35 to 8.55, very low quality evidence). At the end of treatment, the Depression Anxiety Stress Scale (DASS21) change scores in horticultural therapy group were greater than that in the control group (1 RCT n = 22, MD -23.70 CI -35.37 to - 12.03, very low quality evidence). The only included study did not report on adverse effects of interventions.
Based on the current very low quality data, there is insufficient evidence to draw any conclusions on benefits or harms of horticultural therapy for people with schizophrenia. This therapy remains unproven and more and larger randomised trials are needed to increase high quality evidence in this area.
Plain language summary
Gardening activity as a therapy for schizophrenia
Horticultural therapy is based on the therapeutic value of participating in garden activities such as growing fruit or vegetables and/or flowers. Gardening is thought to improve people's well-being through being a recreational and sociable activity which may lead to improvements in people's thinking, new friendships and more positive emotions. The benefits of gardening can also apply to people with serious mental illness such as schizophrenia. Gardening reduces stress, which is important because stress can often lead to mental illness. Gardening is also hard work and a physical activity, and so motivates people with mental illness who often feel tired and apathetic. Weight gain is common for people with mental illness and gardening is good physical exercise.
Since 5% to 15% of people with schizophrenia experience symptoms in spite of taking antipsychotic drugs and also because these drugs have debilitating side effects, horticultural therapy may be of value to these people.
This review focuses on the effects of horticultural therapy for people with schizophrenia. An electronic search for relevant randomised trials was run in January 2013. Only one trial was included, it randomised a total of 24 people with schizophrenia to received either their standard care plus horticultural therapy or standard care only. The trial only lasted 2 weeks (10 consecutive days) with no long-term follow-up. There are few results and the quality of evidence was rated by the review authors to be very low quality. Some of the information from this one study favoured horticultural therapy but there is insufficient evidence to draw any conclusions on benefits or harms of horticultural therapy for people with schizophrenia. More large, better conducted and reported trials are required to determine the effectiveness and benefits of horticultural therapy.
This plain language summary has been written by a consumer Ben Gray, Service User and Service User Expert, Rethink Mental Illness.