Exploring the Link Between Enriched Environment and Depression: Insights From Human Participants

Major depressive disorder (MDD) is a prevalent neuropsychiatric condition associated with significant functional impairment and reduced quality of life. Environmental enrichment (EE), a model encompassing cognitive, social, and physical activities, has demonstrated antidepressant effects in animal models through mechanisms involving brain plasticity. In humans, the influence of EE on depressive symptoms and its clinical significance remain under investigation. This study evaluated the relationship between EE domains and the clinical symptoms of MDD, focusing on the possible modulatory effects of EE on depressive symptomatology.

We conducted an observational, cross-sectional study involving 50 adults diagnosed with MDD. Depressive symptoms were assessed using the 17-items Hamilton Depression Rating Scale (17-HDRS), and EE levels were measured using the Environmental Enrichment Indicator (EEI), which evaluates cognitive, social, and physical activity domains. Correlations between depressive symptoms and EEI domains were analyzed.

Participants with higher 17-HDRS scores generally exhibited lower levels of EE. Additionally, individuals with more severe depressive symptoms were less likely to engage in cognitive activities compared to those with milder symptoms; however, this difference was not statistically significant (Kruskal-Wallis test, H = 3.82, df = 2, p = 0.14). Notably, higher EE levels were observed among younger participants.

The level of EE in individuals with depression may affect symptom severity. Further studies in clinical populations are needed to clarify the relationship between EE and depressive symptoms.