A systematic review of available research literature indicates that horticultural therapy — a therapeutic practice that utilizes plants, gardens, and gardening activities to improve the physical, mental, and emotional well-being of individuals — can be effective in reducing depression symptoms in older adults. The greatest benefits were found for those in care-providing settings participating in horticultural therapy for 4-8 weeks. The study was published in Frontiers in Public Health.
Life expectancy, how long people live, has sharply increased in the last century throughout the world. Many world countries now have elderly populations that constitute large and increasing shares of the total population. Provision of adequate care for this group has become a severe societal problem. Due to this, the overall quality of life of the elderly and ways to improve it has received much research attention.
Aside from different physical maladies, the elderly also experience various types of psychosocial stress due to their peers dying of old age, reduced social contact and living alone. All of this can exacerbate emotions of loneliness and helplessness increasing the risk of depression. Depression can cause great suffering for both persons with depression and their caregivers. It can lead to impaired functioning in their daily lives.
While pharmacological interventions have been considered the primary treatment for depression for a long time, side effects of antidepressant medication have led scientists to look for alternatives. One of the very promising non-pharmacological alternatives for treating depression is horticultural therapy.
Previous studies have shown it to be effective on various populations including healthy people, patients with dementia, schizophrenia and depressive symptoms. However, studies exploring this are many, making it difficult to form a complete picture about their results.
Study author Meijing Xu and his colleagues wanted to evaluate the results of existing studies and provide comprehensive understanding of the effects of horticultural therapy on older adults with depression. The conducted a systematic review (following PRISMA guidelines).
Study authors searched for relevant studies published up to September 25th 2022 in PubMed, Embase, The Cochrane Library, Medline, CINAHL, PsycINFO, Web of Science, Scopus, ProQuest, and four Chinese databases–China National Knowledge Infrastructure (CNKI), Wanfang Data, VIP Data, and Chinese BioMedical Literature Database (CBM).
Studies included in this review were experimental or quasi-experimental studies conducted on persons aged 60 or older that examined the effects of horticultural therapy and included an assessment of depression as the outcome. Studies for which the original research data was missing, for which full text was unavailable, that were not in Chinese or English, as well as conference papers and dissertations were excluded from the analysis.
After screening for all the exclusion criteria, the final review was conducted on a sample of 13 studies, published in 12 papers. Of these studies, 6 were performed in China, 3 in Korea, 3 in Japan and 1 in Poland. 8 of these studies assessed depression using the 15-item Geriatric Depression Scale (GDS-15), with remaining five studies used the 30-item Geriatric Depression Scale (GDS-30). Regarding the environmental setting, 4 studies were conducted in communities, 3 in nursing homes, 4 in special care facilities and 1 in a hospital. 2 studies used intervention in virtual reality instead of a real environment.
Overall studies showed that groups undergoing horticultural therapy treatments had greater reduction in depression symptoms than participants in control groups. However, there were substantial differences in effects between the studies.
The researchers noted that activities conducted in the scope of horticultural therapies differed. In some of the therapies, participants were involved in planting and in others they just walked through gardens. Analysis showed that studies that produced effects were those in which participants were involved in planting, while those reporting no effects on depression symptoms were studies where participants just walked through gardens.
When duration of the horticultural therapy was considered, results showed that in therapies that lasted more than 8 weeks there was mostly no difference between experimental and control groups. However, effects were detected in studies lasting up to 8 weeks.
“In terms of the environment settings, care-providing settings were demonstrated to produce higher therapeutic effects. Participatory activities [where study participants participate in planting or gardening activities] produced greater outcomes than observational activities [in which participants just walked through gardens]. In terms of the duration of the interventions, a course of 4–8 weeks of horticultural therapy had better outcomes,” the study authors conclude.
The study contributes to the systematization of scientific knowledge on effects of horticultural therapy on symptoms of depression on the population of the elderly. However, it should be noted that all studies included in the analysis except for one were conducted in countries in east Asia. Results on other cultures might not be the same.
The study, “Effectiveness of horticultural therapy in aged people with depression: A systematic review and meta-analysis”, was authored by Meijing Xu, Shan Lu, Jianjiao Liu, and Feng Xu.