Effects of Plant-Emitted Monoterpenes on Anxiety Symptoms: A Propensity-Matched Observational Cohort Study.
Davide Donelli, Francesco Meneguzzo, Michele Antonelli, Diego Ardissino, Giampaolo Niccoli, Giorgio Gronchi, Rita Baraldi, Luisa Neri, Federica Zabini
Author Information
Davide Donelli: Department of Medicine and Surgery, University of Parma, I-43121 Parma, Italy. ORCID
Francesco Meneguzzo: Institute of Bioeconomy, National Research Council, 10 Via Madonna del Piano, I-50019 Sesto Fiorentino, Italy. ORCID
Michele Antonelli: Department of Public Health, AUSL-IRCCS of Reggio Emilia, I-42122 Reggio Emilia, Italy. ORCID
Diego Ardissino: Department of Medicine and Surgery, University of Parma, I-43121 Parma, Italy.
Giampaolo Niccoli: Department of Medicine and Surgery, University of Parma, I-43121 Parma, Italy.
Giorgio Gronchi: Section of Psychology, Department of Neuroscience, Psychology, Drug Research and Child's Health (NEUROFARBA), University of Florence, 12 Via di San Salvi, I-50135 Firenze, Italy. ORCID
Rita Baraldi: Institute of Bioeconomy, National Research Council, 10 Via Madonna del Piano, I-50019 Sesto Fiorentino, Italy.
Luisa Neri: Institute of Bioeconomy, National Research Council, 10 Via Madonna del Piano, I-50019 Sesto Fiorentino, Italy. ORCID
Federica Zabini: Institute of Bioeconomy, National Research Council, 10 Via Madonna del Piano, I-50019 Sesto Fiorentino, Italy. ORCID
Immersive experiences in green areas, particularly in forests, have long been known to produce beneficial effects for human health. However, the exact determinants and mechanisms leading to healthy outcomes remain to be elucidated. The purpose of this observational cohort study was to investigate whether inhaling plant-emitted biogenic volatile compounds, namely monoterpenes (MTs), can produce specific effects on anxiety symptoms. Data from 505 subjects participating in 39 structured forest therapy sessions at different Italian sites were collected. The air concentration of monoterpenes was measured at each site. STAI state questionnaires were administered before and after the sessions as a measure of anxiety. A propensity score matching analysis was then performed, considering an above-average exposure to inhalable air MTs as the treatment. The estimated effect was -1.28 STAI-S points (95% C.I. -2.51 to -0.06, = 0.04), indicating that the average effect of exposure to high MT air concentrations during forest therapy sessions was to decrease anxiety symptoms.
