The Great East Japan Earthquake had a psychological impact on many people and such natural disasters can affect the cognitive function of survivors. However, the specific benefits of HT on cognitive functions of earthquake survivors are not clearly understood. This study aimed to determine whether cognitive functions in elderly women living in the Great East Japan Earthquake disaster area would improve following horticultural therapy (HT) using a randomized, open-label, assessor-blind, crossover trial design. Thirty-nine right-handed elderly women participants were divided into an HT group (n = 20) and a control group (n = 19). The HT group underwent eight weeks of HT, and the control group underwent eight weeks of stress control education. We administered four questionnaires to assess changes in participants’ pre- and postintervention cognitive functions. The HT group’s depression, posttraumatic stress disorder symptoms, and cognitive function improved postintervention, particularly in attentional functions and processing capacity, relative to the control group. These findings suggest that HT may improve cognitive functions in elderly women following a disaster.
