Proximity to Greenspace Improves Mental Health
If you follow our blog, you notice recurring themes.
We write about addiction and recovery, of course, because that’s our purpose. We help people with substance use disorder – whether it’s opioid use disorder (OUD), alcohol use disorder (AUD), methamphetamine use disorder (MUD), or another substance – learn to manage the symptoms of their disorder, move past the cycles of addiction, and build a life in recovery.
Related to our articles on addiction, which include in-depth, data-based pieces on the opioid crisis, tips for managing triggers, or suggestions on lifestyle changes that support recovery, such as exercise, mindfulness, and healthy eating, are our articles on mental health issues, which we typically discuss using the term co-occurring disorders. When a person has a substance use disorder and a mental health disorder at the same time, they receive a diagnosis for a co-occurring disorder.
The reason we spend time sharing information on mental health issues – separate from addiction topics – is that the two are related. The things that exacerbate mental health issues typically exacerbate addiction issues, and the things that exacerbate addiction issues also typically exacerbate mental health issues.
The opposite is also true, generally speaking. The things that help individuals manage mental health issues and report improvement or progress are also often the same things that help individuals manage addiction issues and report improvement and/or progress.
That’s why an article we discovered recently has our attention right now. We’re interested in anything that might affect – positively or negatively – the mental health of people in the U.S., which, in turn, affects rates of substance use and addiction in the U.S. The article, called “Perceptions of Green Space Usage, Abundance, and Quality of Green Space Were Associated With Better Mental Health During The COVID-19 Pandemic.”
The title gives away the conclusion, but that’s not what’s important: what’s important is that this study adds weight to the idea that green space can support addiction recovery – and potentially decrease rates of addiction – as a function of its benefit to overall mental health.
Before we get into the details of the study, we’ll review the reason it’s important: the prevalence of mental health disorders among people with SUD, which we define above as co-occurring disorders.
Mental Health and Addiction in the U.S.: Facts and Figures
If you’re familiar with the concept of co-occurring disorders, please read on. If not, please have a look at these articles on our blog:
Mental Health Awareness Month 2022: The Connection Between Mental Health and Addiction
Comorbid PTSD and Substance Use Disorder
If you’re familiar with the relationship of greenspace, or green-time, and mental health/addiction, please read on. If not, please have a look at this article by our Chief Clinical Officer, Lori Ryland, Ph.D.:
Green Time, Blue Time, and Self-Care During Recovery: Part One
And the follow-up to that article here:
Green Time, Blue Time, and Self-Care During Recovery: Part Two
Those articles are relevant to our work in addiction recovery – as is this one – because the latest data from the National Institutes of Health (NIH) indicate that rates of mental health disorders are increasing, rates of substance use disorder are increasing, and rates of co-occurring addiction and mental health disorders are also increasing.
First, we’ll look at the data from 2018, which we retrieved from the 2018 National Survey on Drug Use and Health (2018 NSDUH).
Mental Health Disorders and Substance Use Disorder in the U.S: 2018
- 6 million people over age 18 (adults) had a clinically diagnosed mental illness
- That’s almost 20% of adults
- 11.4 million adults had a serious mental illness
- That’s almost 4% of adults
- Among the 47.6 million adults with a clinically diagnosed mental illness:
- 9.2 million had an SUD
- That’s just over 19%
- In contrast, among adults without a mental health disorder:
- 5% had an SUD
- Among the 11.4 million adults with a serious mental illness:
- 28% also had an SUD
- 9.2 million had an SUD
That data, published in 2019 – before the pandemic – shows that 9.2 million people with mental illness had SUD, and that 3.1 million people with a serious mental illness had SUD. Now let’s take a look at the data from 2020, which include information collected during COVID-19.
Mental Health Disorders and Substance Use Disorder in the U.S: 2020
- 52.9 million adults 18 + had a clinically diagnosed mental illness
- That’s just over 20% of the adult population
- 14.2 million adults had serious mental illness (SMI)
- That’s over 5% of the adult population
- Among the 52.9 million adults with a clinically diagnosed mental illness:
- 17 million had an SUD
- That’s 32% – almost 1/3rd of adults with SUD
- In contrast, among adults without a mental health disorder:
- 14% had an SUD
- Among the 14.2 million adults with a serious mental illness
- 5.7 million had SUD
- That’s 67% – or 2/3rds of adults with serious mental illness
- 5.7 million had SUD
- 17 million had an SUD
Let’s compare key points from those two sets of data. Between 2018 and 2020:
- The number of people with a mental illness increased by 5.3 million
- The number of people with a serious mental illness increased by 2.8 million
- Among people with mental illness, the percentage of people with SUD almost doubled
- Among people with serious mental illness, the percentage of people with SUD more than doubled
Notice we write the percentage of people with mental illness and SUD almost doubled from 2018 to 2020, and the percentage of people with serious mental illness and SUD more than doubled from 2018 to 2020. The numbers are up across the board, but what’s most concerning are the relative percent increase in prevalence, because those numbers show that not only the prevalence of mental illness in the U.S. increased between 2018 and 2020, but also among people with mental illness, with proportion SUD increased between 2018 and 2020.
Logic tells us that the COVID-19 pandemic caused these increases, but that’s not what this article is about: this is about how a default element of an individual’s environment – the presence of greenspace – can have a significant impact on mental health, and therefore, on the prevalence of substance use disorder.
Let’s take a look at that study.
Greenspace: Stress, Depression, and Anxiety
Between November 2019 and January 2020, researchers collected information from over 1,200 residents of Denver, Colorado. The initial goal of the study was to study their perceptions of the greenspace near their home and analyze its effect on their mental health.
Researchers asked the following questions about greenspace:
How much greenspace is near your place of residence?
Can you see trees or any kind of greenspace from your window?
Do you use it?
Do you consider it high quality?
To confirm the answers, researchers used satellite imagery. With regards to high quality greenspace, researchers sought to distinguish, for instance, between an overgrown vacant lot and an intentionally landscaped park – distinctions it’s not always possible to make with commercially available satellite imagery.
One of the most interesting things about this study was that it was underway when the pandemic began, which enabled the researchers to engage in the type of before-and-after analysis that not many studies on the pandemic were able to conduct.
Here are the metrics they used to analyze their data:
- Stress: a 4-item stress scale called the Perceived Stress Scale (PSS-4)
- Depression: a 10-question depression scale called the Center for Epidemiological Studies Depression Scale (CESD-10)
- Anxiety: a 23-item inventory/questionnaire called the Minnesota Multiphasic Personality Inventory-2 Anxiety Scale (MMPI-2 Anxiety)
- Perceived green space exposure: a questionnaire derived from a paper called “Multiple Pathways Link Urban Green- and Blue-space to Mental Health in Young Adults”
- Objective green space exposure: living 300-500 meters from greenspace identified in satellite imagery from the National Agriculture Imagery Program (NAIP) and the Normalized Difference Vegetation Index (NDVI), as applied in A Review of the Health Benefits of Greenness
Those mental health metrics are standard, and in use around the world every day. The greenspace questionnaire was tested by urban planners and mental health experts, while the satellite imagery is in regular use by citizens and government officials for a variety of purposes.
Results: The Effect of COVID-19 on Mental Health
First, let’s look at the impact of COVID-19 on mental health, aside from any discussion of greenspace. Here’s the overall impact they observed when they compared answers from before the pandemic (November 2019-March 2020) and after the onset of the pandemic (March 2020-January 2021):
- Stress: increased
- Depression: increased
- Anxiety: increased
In addition, time spent using greenspace increased by 33 percent between March 2020 and January 2021, compared to November 2019 – March 2020. As expected, and as confirmed by studies conducted around the country at the same time, stress and related mental health issues increased the presence of stress, depression, and anxiety.
Results: The Effect of Greenspace on Mental Health During COVID-19
Now let’s look at how the relationship greenspace affected stress, depression, and anxiety among the 1200 study participants.
Presence of Objective and Perceived Greenspace and Mental Health
- Stress, as measured by the Perceived Stress Scale(PSS-4):
- Decreased
- Depression, as measured by the Center for Epidemiological Studies Depression Scale (CESD-10):
- Decreased
- Anxiety, as measured by the Minnesota Multiphasic Personality Inventory-2 Anxiety Scale (MMPI-2 Anxiety):
- Decreased
- When researchers adjusted for sociodemographic factors and the impact of COVID-19 health and financial concerns:
- Spending time in greenspace was associated with:
- Decreased depression
- Decreased anxiety
- Proximity to greenspace was associated with decreased depression
- Spending time in greenspace was associated with:
Let’s unpack some of that data.
The first thing we notice is that last series of bullet points. When the researchers adjusted for sociodemographic factors – which means they used statistical analysis to eliminate the influence of age, income, sex, ethnicity, marital status, and employment – they found something unexpected. Individual perception of presence or quality of greenspace had no impact on depression or anxiety. However, spending time in greenspace reduce both depression and anxiety. In addition, proximity to greenspace – proximity being the only true objective measure in the study – had a significant impact on reducing the prevalence of depression, but not anxiety.
It’s also important to note that the presence of greenspace reduced stress across all metrics before controlling for sociodemographic factors, but reductions in stress disappeared when researchers controlled for those factors. What that means is that with regards to stress, it may not have been just the greenspace that reduced stress – factors like income, marital status, and employment may have also played a role.
How This Helps Us Help Our Patients
On a basic level, the data in this study adds to the growing body of evidence that greenspace is a protective factor that can reduce the risk of mental health issues, such as depression and anxiety. It also, therefore, supports the idea that the presence of greenspace may be a protective factor that can help reduce the risk of developing substance use disorder, since the relationship between substance use disorder and mental health issues is well-established, as we demonstrate above with data from the 2018 and 2020 National Surveys on Drug use and Health (2018/2020 NSDUH).
This research also reinforces our focus on the positive influence of greenspace – specifically, getting outdoors and spending time in nature – on the process of recovery. The presence of greenspace is associated with a reduction in levels of stress, depression, and anxiety, which are all risk factors for relapse. Therefore, again, it follows that time spent in greenspace – because it’s protective of mental health – may be associated with a reduced risk of relapse.
That’s important. It tells us that by using the integrated treatment model – which emphasizes a holistic, whole-person approach to recovery – we’re on the right track. Recovery points us toward a concept of total health that includes a host of habits that support mental health during the best of times. Total health also supports us when life – as it has over the past two and a half years – gets stressful.
Here’s how study author Colleen Reid, Ph.D., views this data:
“This research shows how critical it is to keep parks and green spaces open in times of crisis. It also shows that, as a public health measure, more effort should be made to put in green spaces and make them accessible.”
Her colleague and co-author Emma Rieves, Ph.D., agrees:
“Greenspace could have a powerful protective effect, even at a time of extraordinary stressors.”
We agree. It’s hard not to see the benefits of increasing the amount of greenspace in physical spaces like our cities and towns. We also need to see the benefits of increasing the amount of greenspace in our lives, which takes conscious effort. That’s another lesson for and from recovery: we practice good, protective habits daily – whether the days are good or challenging – so they’re ready for us when we need them most.