A systematic review of horticultural therapy and urban agriculture interventions targeting depression, anxiety, and acute stress disorder

Mental ill-health is a major concern in urban settings, particularly in relation to conditions such as depression, anxiety and acute stress disorder. Research has demonstrated the potential for horticultural therapy (HT) interventions that draw on urban agriculture practices and methods to address this issue. However, there is a paucity of evidence to support the potential for these interventions for individuals with pre-existing diagnoses. The aim of this systematic review was to address this gap in the literature by evaluating the efficacy of HT interventions as well as the methodologies employed in each study. We searched four bibliographic databases, and identified eleven studies for inclusion in the review, and reported generally favourable results: six studies reported improvements for depressive symptoms; three found that HT interventions mitigated stress; and two studies reported a positive influence on anxiety. Over two thirds of the included studies had either moderate (n = 6) or high (n = 2) risk of bias, and there was a high degree of methodological heterogeneity. In addition, the number of studies was small, therefore the generalisability of the findings is limited. Further research is needed to establish a robust causal link between HT interventions and improved mental health outcomes among populations with pre-existing diagnoses.