Depressive symptoms and memory problems are risk factors for dementia. Exercise can reduce these in older people, and horticultural activity can benefit people with dementia. This study assessed the efficacy of exercise and horticultural interventions for community-dwelling older adults with depressive symptoms and mild memory decline. In this randomized controlled trial, older adults (n = 89) were assigned to exercise, horticultural, or control groups. Exercise and horticultural programs included 20 weekly 90-minute sessions. The control group attended two 90-minute classes. Outcomes were assessed at baseline, and then 6- and 12-months post-intervention. Primary outcome measures were the Geriatric Depression Scale-15 (GDS-15) and Wechsler Memory Scale-Revised. Walking speed, two-minute walking test scores, social network, life space, and subjective daily physical activity were secondary outcome measures. Compared with the control group, the exercise group obtained higher immediate and delayed recall logical memory scores, and the increase in immediate recall scores remained 12-months post-intervention. Two-minute walking performance improved in the exercise group, but not after 12 months. GDS-15 scores showed no significant improvements. The horticultural and control groups showed no differences. Exercise may improve memory, while horticultural activity may not. The effects of exercise and horticultural interventions on depressive symptoms remain unclear.
Keywords: aging; depression; exercise; horticulture; memory.