How Environmental Factors Impact Mental Health

Ranked as one of the leading causes of illness and disability around the globe, mental illness is a widespread health challenge. In fact, data from the World Health Organization reveals that approximately one in four people worldwide will suffer from a mental illness at some point in their lives. While there are still plenty of researchers and clinical psychologists alike who don’t know about mental illness, one thing is for sure: these conditions are complex and multi-causal. Many people often assume mental illness simply runs in families. This is true, but genetics are only a part of it. These disorders actually occur due to a combination of factors, including a person’s environment and lifestyle.


The world a person lives and functions within can play a major role in mental health. Below, we’ll talk about two types of environmental factors that can make a person susceptible to mental illness.


Scientists define “environment” in the realm of mental illness broadly, some going so far as to suggest it encompasses everything that isn’t an inherited gene. That’s a departure from traditional thinking in environmental health, however, which has historically viewed environmental threats in the context of infectious agents, pollutants, and other exogenous factors that influence the individual’s physical surroundings. Environmental threats to mental health include these traditional parameters—along with pharmaceutical and illicit drugs, injuries, and nutritional deficiencies—but also consist of psychosocial conditions that relate to the individual’s perceptions of the social and physical world.


Any number of circumstances—for instance, sexual abuse, falling victim to crime, or the breakup of a relationship—can produce psychosocial stress. But experts assume each of these circumstances triggers more primal reactions, such as feelings of loss or danger, which serve to push victims toward a particular mental state. “Feelings of pure loss might lead to depressive disorders, while feelings of pure danger might lead to anxiety disorders,” explains Ronald Kessler, a professor of health care policy at Harvard Medical School. “And feelings of loss and danger might lead to both simultaneously.” Either alone or in combination, psychosocial and physiological stressors can interact with a genetic vulnerability to alter brain chemistry and thus alter the individual’s mental health.


Several lines of evidence point to an environmental role in psychiatric disease. Among identical twins, if one becomes schizophrenic, the risk to the other is on average less than 50%, suggesting that environmental influences must somehow be involved. Similar findings have been observed with depression and other mental disorders.


Scientists have traditionally been challenged in their efforts to link mental illness with underlying causes, in part because the diseases are so amorphous, says Ezra Susser, a psychiatrist and department chair in epidemiology at the Columbia University Mailman School of Public Health. Unlike cancer or heart disease, which have clearly visible endpoints, mental disorders yield vague behaviors that vary widely among individuals. “They’re defined mainly by thoughts, behaviors, and feelings,” Susser says. “We don’t have biological measures on which to rest our diagnoses.”


Physical Environmental Factors

Physical environmental factors contributing to mental illness are those that have the power to affect a person’s biology or neurochemistry, thereby increasing their chances of developing a disorder. For example, if a person lacks access to health-related resources such as whole, nutrient-rich foods and tends to eat more processed and refined foods, their body (and brain) won’t function optimally. As a result, if they encounter a major stressor, they may not have the resources to effectively cope.


In addition to poor nutrition, some other examples of physical environmental factors are:

  • Sleep deprivation

  • Smoking

  • Substance abuse

  • Pollution

  • Exposure to toxins during childhood

  • Extreme weather conditions (such as excessive rain or snow)

  • Hazardous conditions at work

Social Environmental Factors

Social environmental factors refer to socioeconomic, racial and ethnic, and relational conditions that may influence a person’s ability to cope with stress. A good example is not having a strong social support system. Let’s say a person loses their job or goes through a divorce. Having supportive friends and family during this time is vital to their ability to cope with the stress.

A lack of social support is just one type of social-environmental factor. Others include:

  • Social stigma (such as coming out as gay or lesbian)

  • History of abuse

  • Family discord during childhood

  • Early loss of a parent

  • Poverty

  • Lack of spirituality or religious affiliation