According to statistics from the World Health Organization, more than 300 million people worldwide are affected by varying levels of depression. On average, about 800,000 people commit suicide annually. This number is increasing every year. Between 2005 and 2015, the global prevalence of depression increased by 20%. Although there are effective pharmacological treatments for depression, only 10% of those affected have access to these treatment methods. In many cases, even diagnosis is not possible. Depression is the result of complex and diverse factors, but it can be simplified to two biological and genetic factors.

According to statistics published in 2018 by the head of the Iranian Psychiatric Association, depression, anxiety, and aggression are the most common mental disorders in Iran, followed by OCD, sleep disorders, and behavioral disorders. The statistics from this association also show that the number of women affected by these mental health problems is twice as high as men.

What is noteworthy is the high prevalence of mental disorders in

Environmental psychology

Can a meaningful relationship be found between mental disorders, especially anxiety and depression, in humans and the possibility of living in proximity to nature and animals? Environmental psychology is a relatively new science with a lifespan of less than 50 years. The environment refers to both natural and man-made environments, from places close to us (such as our room, neighborhood) to the largest and most common places (such as big cities). One of the main goals of environmental psychology is to understand and analyze the interactions between individuals and the environment and to use this knowledge to influence policies and operational lines that can promote sustainable behavior and create livable and healthier environments. Therefore, in the late 1960s, attention was paid to architecture, environment, urban spaces, and their impact on interaction with citizens. The interaction between nature and the human mind can perhaps be divided into two important parts.

The effects of nature on psychological well-being.

In particular, the positive impact of natural environments on mental health and citizens’ satisfaction has been repeatedly confirmed. For example, it has been observed how the combination of silence and natural environments leads to greater tranquility and awareness of life and the importance of living in the present moment and enjoying life (Pfeifer et al., 2020). Or how being exposed to nature can lead to a reduction in short-term and immediate mood disorders, as nature can help reduce levels of stress, anxiety, and depression (Dolan, 2018). Even in children (Sobko, 2018), a close and physical relationship with nature can lead to a deep and lasting understanding of themselves and their surroundings, and can help in treating problems such as hyperactivity, emotional issues, and repetitive behaviors.

Environmental Psychology and Neuroscience

Regarding brain neural systems, a collection of studies has shown how life in natural environments can improve amygdala function (which plays an important role in learning and memory). In addition to its main role in understanding emotions and how to react to them, the amygdala also plays a role in pain modulation and displaying the human’s external facial expressions of sensory experiences such as joy and sadness. It is also linked to the brain’s stress response system. Studies on the effects of the environment on brain structures have also shown a negative correlation; for example, various data indicate the detrimental impact of certain environmental conditions. A study conducted by researchers at the University of California suggests a link between air pollution from traffic and an increased risk of changes in brain development. This is especially concerning for those who live in polluted environments for extended periods of time, as it can lead to neurological disorders.

In summary, their research on various animals has shown abnormal growth and increased neuroinflammation in the brains of animals exposed to air