In recent decades, the global burden of mental health illnesses has increased manifold. The World Health Organization (WHO) states that mental illnesses or disorders are generally characterised by a combination of abnormal thoughts, perceptions, emotions, behaviour, and relationships with others. These disorders are many and have very different presentations. Some of the most common mental health disorders are depression, bipolar disorder, schizophrenia, dementia, psychosis, and developmental disorders including (but not limited to) autism.The burden of just depression on the world right now is immense. The WHO estimates that there are around 264 million people are affected by depression, globally. According to a study published in The Lancet Psychiatry in 2019, titled The burden of mental disorders across the states of India, an increasing portion of this global burden is being carried by India. The study states that in 2017, 197.3 million people in India suffered from mental disorders, including 45.7 million with depressive disorders and 44.9 million with anxiety disorders. The study also found a significant correlation between depressive disorders and suicide death rates across all states of India, and among both men and women.It suffices to say that dealing with mental health issues, especially depression, is something we all need to do with some urgency. But can adopting a sustainable, eco-friendly, or green life equip you a little better in this global fight for improved mental health conditions? Lets find out!The link between sustainability and mental healthThe world we live in impacts every aspect of our lives, including our mental health. This is an undeniable fact, and one that clearly establishes the idea that environmental factors do have a huge role to play in our mental health. A 2019 news report by the United Nations Environment Programme (UNEP) explains that the idea of living in the middle of a universal climate crisiswhich inevitably leads to everything from economic uncertainty and lack of job security, to volatile weather patterns, natural disasters, food insecurity, and displacement of communitiesdoes have a deep impact on our mental health. But what is the climate crisis if not the result of human actions and lifestyles?Adopting a sustainable, environment friendly lifestyle may not seem like a solution to the grave and intensifying problem that is the global climate crisis, or your mental health issues, but studies show that it may just be. If youre having a hard time believing this then read on to find out the many ways in which environmental factors may affect your mental health, and how a green life can help you tackle with the issues they may throw up.How green spaces affects mental healthFirst, lets take our immediate living conditions into account. There is a global increase in the number of people who live in urban centres instead of rural ones, and India is one of the few countries leading this charge. According to a 2018 report titled Revision of World Urbanization Prospects by the United Nations Department of Economic and Social Affairs (UNDESA), 68 per cent of the worlds population will live in urban areas by 2050, with India alone accounting for around 416 million added urban dwellers during this time frame. But, no matter what the benefits of urban life, there are a number of costs that we do have to pay.A study published in the British Journal of Psychiatry International in 2017, titled The importance of greenspace for mental health, explains that urbanisation has reduced human access to and engagement with green spaces like nature reserves, wilderness environments, and urban parks. And yet, individuals who have access to such green spacesor even natural blue ones like rivers, lakes, and coastsare shown by the study to have less mental distress, less anxiety, and depression, greater mental well-being and healthier cortisol (the primary stress hormone) profiles. The study even suggests that those who engage in physical activity in green spaces in your city, also known as green exercise, at least once a week have about half the risk of poor mental health compared with those who do not do so.This not only highlights the need for more green spaces in urban areas, but also your need to engage with it to maintain good mental health.How eating habits affect mental healthHave you ever heard the term nutritional psychiatry? If not, you should know that its based on the gut-brain axis. The human body maintains a delicate balance of microorganisms, like bacteria, which help with natural and optimal functions. The bacteria in the gut, for example, release enzymes that not only help digest food and produce energy, but also dictate the release of all the hormones and neurotransmitters your brain needs to function properly. This intricate link between the gut and the brain, known as the gut-brain axis, indicates that what you eat has a direct impact on your mental health via the balance of hormones maintained by your body.A 2019 study published in Translational Psychiatry, titled The effects of plant-based diets on the body and the brain, explains that although the exact neural mechanisms are not yet fully understood, a plant-based diet helps maintain the microbial composition of the body better, and therefore has a positive link with neurological functions that are associated with emotional distress and mental illnesses. On the other hand, a more processed, unbalanced, or unhealthy diet is linked to greater incidence of mental health issues because it harms the guts ecosystem in the long and short terms.Now, guess which diet is considered to be the most sustainable and environment-friendly one? Yes, its a plant-based diet! So, this proves that whats good for the planet is also great for your gut and your mental health.How pollution affects mental healthThe fact that pollution of all types, be it air, water, or soil, is one of the biggest threats to Mother Nature, and one of the greatest contributors to the climate crisis, is well known. Pollution has a huge negative impact on our ecosystems, and is known to lead to grave problems like loss of biodiversity and increasing ozone gas. Air pollution, in particular, gets a lot of attention because its levels have shot up exponentially over the last decade, and the effects on human health are quite visible. From lung damage and chronic obstructive pulmonary disease (COPD) to asthma and heart disease, research shows air pollution can cause it all. But did you know that air pollution is linked to mental health disorders too?According to the American Psychological Association (APA), chronic exposure to high levels of air pollution has the potential to damage childrens cognitive abilities, increase the risk of cognitive decline in adults, and can even contribute to depression. Particulate matter pollution, which is caused not only by vehicular and industrial emissions but also household emissions from barbeques, incense sticks, cooking medium, cleaning equipment and products, etc is a major culprit. The APA says that a number of studies conducted in recent years show that particulate matter can enter through the olfactory organs and cross the blood-brain barrier to affect our neural/mental functions. This can not only cause cognitive impairment and decline, but also lead to dementia and mental health problems.While only further research into this field can help us understand the true extent of the damage caused by air pollution to our mental health, its quite evident that reducing air pollution levelsat home, in your city and the worldis only likely to benefit your mental health.Its also clear through all of these links between the environment, climate crisis and your mental health, that adopting a green lifestyle which is environment friendly and sustainable is most likely to benefit your mental health. You may want to start your commitment to sustainability with your diet by making it more plant-based, or by moving to a place that offers you more engagement with greenery (or creating green urban spaces around you), or by attempting to minimise your contribution to pollution by adopting methods like recycling, better waste management, and making more informed choices as a consumer. No matter which road you take towards sustainability, you can be sure that it will not only help the planet get a little bit healthier. Sustainability will help improve your mental health too.