Gardening May Weed Out Dementia-Related Apathy

Batya Swift Yasgur, MA, LSW

April 22, 2021

Horticulture therapy (HT), a novel intervention that uses plants, horticultural activities, and the natural environment, reduces apathy and improves cognitive function for patients with dementia, new research suggests.

Results of a small, randomized, 10-week trial showed that apathy among patients in the HT group was significantly lower compared to those in the control group. In addition, investigators found that cognitive function in the active-treatment group also improved. However, the improvements were not significantly sustained 3 months post intervention.

"This study shows that HT is feasible in residents with dementia, as observed in a small sample," the investigators, headed by Yi Yang, Department of Nursing, Medical School, Taizhou University, Zhejiang, China.

"Preliminary evidence supports that this HT program may reduce apathy and promote cognitive function," they state.

The study was published online April 5 in Aging and Mental Health.

Adverse Outcomes

"Apathy is one of the most common behavioral and psychological symptoms of people with dementia" and is "common in Alzheimer's type dementia," the authors write. They note that apathy is "associated with a number of adverse outcomes."

They refer to the "biophilia hypothesis," which "explains an emotional connection between human beings and other living things" that is "vital for maintaining physical and mental health."

Previous studies have found benefits from HT (including both indoor and outdoor gardening activities) for people with dementia. It provides a "sense of peace and shelter, effectively reducing stress, depression, anxiety, and improving the quality of life," the authors state. HT activities include moderate physical exercise, which can improve flexibility, physical strength, and cognitive ability.

Prior research has found that people with dementia and apathy spend "a greater proportion of time exhibiting active and passive engagement in HT activities than in non-HT activities."

Additionally, HT activities "may attract the engagement of people with dementia through the medium of plants," and "engagement is the antithesis of apathy." However, more research is needed to confirm that HT activities can indeed alleviate dementia-related apathy.

The researchers assessed recruitment rate, retention rate, attendance rate, and completion rate and the effects of HT on apathy, cognitive ability, quality of life, and functional capacity.

Planting, Handicrafts, Cooking

The researchers recruited 141 nursing home residents with Alzheimer's type dementia and apathy, of whom 22.7% (n = 32; median age, 84.5 years; interquartile range [IQR], 9.5 years) were included in the study.

Participants were randomly assigned to receive either HT plus usual care (n = 16) or usual care only (n = 16).

Usual-care activities consisted of singing, calisthenics, and puzzle games, which were provided twice a week.

HT sessions were conducted once a week for 10 weeks. There were three categories of activities:

  • Planting (planting, growing, and harvesting): four sessions

  • Handicraft (use of natural materials to make handicrafts): four sessions

  • Diet (eating, drinking, and cooking plants): two sessions

Although the intervention was delivered in a group setting, the activity leader focused attention on each individual — for example, by asking participants about their previous experiences in gardening, farming, and cooking and how they felt about HT activities. One-on-one activity assistants "kept an eye on the participants throughout the activities to encourage or help them promptly."

At baseline, there were no significant differences between the two groups in demographic and clinical profiles, including age, gender, marital status, educational level, and dementia severity.

The primary outcome of the study was apathy, which was assessed with the Apathy Evaluation Scale–Informant Version (AES-I). Secondary outcomes included cognitive function, asssessed with the Mini–Mental State Examination (MMSE); quality of life, assessed with the Quality of Life in Alzheimer's Disease scale; and functional capacity, assessed with the Barthel Index.

"Appropriate and Attractive" Stimulus

At 10 weeks, the HT group had significantly lower apathy scores compared to the control group (AES-I: median, 47.5 [IQR, 13.0] vs 55.5 [IQR, 10.0]; P = .007). However, the significant difference was not sustained at 3 months post intervention (53.5 [IQR, 18.0] vs 57.0 [IQR, 10.0]; P = .289).

At 10 weeks, cognitive function in the HT group was significantly higher than in the control group (MMSE: median, 10.5 [IQR, 13.0] vs 7.0 [IQR, 6.0]; P = .034). However, as with apathy, improvements were not sustained at 3 months.

There were no between-group differences in quality of life and functional capacity, either post intervention or at 3 months.

The researchers conducted a within-group analysis, which yielded promising findings: In the HT group, there were significant improvements in apathy, cognitive function, and quality-of-life scores at 10 weeks.

"HT reduces apathy, possibly by providing participants an appropriate and attractive external stimulus," the authors suggest. They note that "tailoring of activities may also help to reduce apathy" and that HT was tailored and simplified so that even residents with severe dementia could participate.

"Through the tailoring of activities, participants were not discouraged by the difficulty of specific tasks," they report.

The authors note several study limitations — for example, the small sample size and the use of an informant scale to measure apathy.

Promising Findings

Commenting on the study for Medscape Medical News, Claire Sexton, DPhil, director of scientific programs and outreach at the Alzheimer's Association, called it a "lovely study with promising results, although it was a pilot study."

The findings have an important take-home message, according to Sexton, who was not involved with the study.

"There is no one-size-fits-all. The type of activities suitable for an individual with dementia will change over time as people progress through different stages of the disease and are also individual to each person, based on personality, interests, and previous experience."

For people who enjoy gardening, HT could be a very helpful intervention, but "we always have to take into account what types of activities people enjoy and how to adjust them to different stages — a personalized approach is recommended as much as possible," Sexton emphasized.

The study received no funding. The authors and Sexton have disclosed no relevant financial relationships.

Aging Ment Health. Published online April 5, 2021. Abstract

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