Can indoor plants heal anxiety and depression in college students?

A 2025 honors thesis from the University of South Dakota examined a timely question: Can indoor plants meaningfully reduce anxiety and depression in college students? The paper, titled Let’s Grow: Investigating the Relationship Between Houseplants and Mental Health in College Students, reviewed existing research on indoor plants and their association with anxiety and depression in higher education settings.

The conclusions are careful and measured. The evidence is mixed, but trends in a positive direction. At this stage, the research suggests potential benefit, not definitive proof. Let’s explore what we know so far…

The scope of the review

The thesis conducted a structured literature review using Google Scholar and Academic Search Complete. To be included, studies had to:

• Focus specifically on college students
• Examine indoor plants as the independent variable
• Measure anxiety and/or depression as outcomes

Studies examining ecotherapy, such as gardening or forest-bathing, were excluded. Research focused only on outdoor exposure or cognitive performance was also excluded. After screening, ten studies met the criteria:

• Six experimental studies
• Four observational studies

The independent variable was the presence of and/or interaction with indoor plants. In this particular review, mental health referred specifically to reported levels of anxiety and depression symptoms.

The overall pattern

The results were not unanimous. Of the six experimental studies:

• Three reported statistically significant improvements in mental health.
• Three found no measurable effect.
• All four observational studies reported a positive association between houseplants and improved emotional well-being.

These details matter. Observational research can reveal patterns in real-world environments, but it does not prove causation. Experimental studies are better at proving cause and effect, yet only half of them reported benefits. As a result, the relationship between indoor plants and mental health in college students remains an area of emerging research rather than definitive proof.

Which factor made the biggest difference?

The thesis identified three variables worth noting: time spent with plants, location of plants, and nature of interaction.

Time with plants. Even though minimal exposure frequently coincided with positive results, the duration of exposure did not significantly change outcomes. Participants interacted with plants for as little as 15 minutes or had them in their living spaces for weeks. Mental health results for the particular research reviewed did not consistently vary based on the length of exposure.

Plant location. In this review, studies placing plants in communal academic spaces did not consistently show measurable changes in anxiety or depression. By contrast, residential settings were more likely to be associated with improved mood. Remember, however, that these findings pertain only to symptoms of anxiety and depression, and do not address other potential benefits of plants in shared campus environments, such as aesthetic quality, perceived comfort, or environmental satisfaction. They also involved short-term academic task environments, which may differ substantially from real-world campus installations designed for longer-term engagement and environmental enhancement.

Nature of interaction. One experimental study requiring structured, guided plant care found no mental health improvement. In contrast, studies allowing more autonomous interaction were more likely to report positive outcomes. The thesis discusses this pattern through the lens of Self-Determination Theory, which emphasizes autonomy as a factor in well-being. This highlights the idea that how plants are integrated into a person’s life impacts their affect.

Limitations of this research and why we need more information

The author clearly outlines the limits of the current evidence:

• No studies focused exclusively on clinically diagnosed populations.
• Sample sizes were often small.
• Study designs varied widely.
• Long-term, longitudinal research is limited.
• Mechanisms explaining why plants might affect mental health remain unclear.

The thesis also raises the broader issue of publication bias and p-hacking in psychological research. These factors warrant caution when interpreting early findings: the evidence is promising but not conclusive.

Where stronger evidence exists

While research on indoor plants and college students is still developing, other areas of plant-related research are more established.

Meta-analyses of nature-based interventions have shown consistent reductions in anxiety and depression symptoms in broader populations. Studies of indoor plants in office environments have documented measurable physiological changes, including reductions in heart rate and self-reported stress.

Research conducted in built environments, particularly workplaces, has found associations between indoor greenery and improved mood, reduced stress indicators, and enhanced perceived environmental quality. Many experimental studies in controlled indoor settings have demonstrated clearer effects than those found in small student samples.

These bodies of research do not directly answer the question about college dorm rooms, but they do strengthen the broader case that interaction with natural elements indoors can influence human well-being.

Here’s what we know for certain

Based on the 2025 review, the relationship between indoor plants and college student mental health can be summarized this way:

• There is evidence of a positive association.
• Experimental results are mixed.
• Observational results are consistently positive.
• Duration of exposure appears less important than context.
• Autonomy in interaction may influence outcomes.
• More rigorous, standardized research is needed.

At this stage, indoor plants should not be described as a proven mental health intervention for college students. However, the emerging literature suggests they may contribute to emotional well-being, especially when students consciously choose to notice and interact with them.

As research continues to evolve, clarity will increase. For now, we know that indoor plants are low-cost, accessible, and physiologically supportive elements in indoor environments. The scientific community is still refining how strong that support may be, and under what circumstances it is most effective.