Effect of Horticultural Therapy on the Stress and Serum Cortisol of Demented Elders

This study was conducted in order to examine the effects of horticultural therapy on stress in demented elders, and for this purpose, we analyzed stress-related physiological changes in demented elders under the care of an elderly facility who had not taken medication and consented to blood tests. The horticultural therapy program included only flower decoration, which was preferred by the participants, aiming ultimately to reduce stress. First, a one-to-one session was given for forming rapport and the horticultural therapist had many conversations about plants with the elders. Furthermore, the participants were induced to be absorbed into the horticultural activities, though a short while, so that they might forget troubles. Evaluation was made by measuring subjective stress and the blood cortisol hormone concentration before and after the horticultural therapy and examining differences between them. Subjective stress increased from 12.88 to 17.88 in the control group, but decreased significantly from 13.88 before the therapy to 6.38 after in the experimental group (p = 0.007). When the blood cortisol hormone level was measured as a physiological indicator of stress, it decreased significantly from 11.33 mu g.L-1 before the horticultural therapy to 9.85 mu g.L-1 after (p = 0.037). These results suggest that horticultural therapy reduces the blood cortisol hormone level and is effective in easing stress.