An Indoor Therapeutic Garden for Behavioral Symptoms in Alzheimer's Disease: A Randomized Controlled Trial.

Background: Behavioral and psychological symptoms of dementia (BPSD) affect 60-90% of patients with Alzheimer's disease (AD).

Objective: To determine if environmental therapy is an effective strategy to reduce BPSD, we tested 163 patients with AD with Neuropsychiatric Inventory (NPI) before and after 6 months of an indoor therapeutic garden (TG) or standard environment.

Methods: A single-blind randomized controlled trial on AD patients with BPSD. Participants were randomized to an indoor TG (N = 82), or standard environment (control, N = 81) for 6 months.

Primary Outcome: change in the NPI score from baseline (T0) to end of treatment (T1).

Secondary Outcomes: change in use of quetiapine, cognition, activities of daily living, salivary cortisol, blood pressure from T0 to T1.

Results: NPI score significantly ameliorated (TG versus control: -31.8 points), quetiapine dosage (-150 mg), blood pressure (-2.6 mm Hg), and salivary cortisol (-6.4 to -2.1 Nmol/l) were significantly reduced, the Mini-Mental State Examination significantly improved (1.8 points) in the TG versus control arm at T1 (p < 0.001). No adverse events were reported.

Conclusion: The indoor TG seems safe and may reduce BPSD, medication intake, and cortisol levels in AD.