For many Americans, our health — particularly our mental health — is often taken for granted until something goes wrong. Only then do we realize just how important health is to our sense of fulfillment and happiness.

After all, in today's fast-paced, technological world, there are often a variety of quick treatments for physical ailments, but not so for mental ones. If anything, treatments for mental health take time and patience for maximum effectiveness. In order to understand exactly what is meant by "mental health," we need to first define what the overarching concept of "health" means.

In the past, scientists in the past defined health simply as "an absence of disease or illness." However, in 1948, when the World Health Organization (WHO) was founded, the following definition of health was established: "A complete state of physical, mental and social well-being and not merely the absence of disease or infirmity."

Looking at this definition, we realize that individuals can at once be relatively healthy in some aspects of life (e.g., normal blood pressure of 120/80 mmHg), but unhealthy in others (e.g., suffering from depression). Thus, being healthy is not an "all-or-nothing" principle.

It is easy to assess physical health by taking health status measurements of the body. Blood pressure, temperature, and cholesterol levels, are all precise means by which we can tell if the physical components of the body are healthy. However, mental and social components of health are much more challenging to assess. Thoughts and perceptions of internal states are subjective and difficult to quantify. What then is mental health?

Mental health, as defined by the Surgeon General's Report on Mental Health, "refers to the successful performance of mental function, resulting in productive activities, fulfilling relationships with other people, and the ability to adapt to change and cope with adversity." On the other end of the continuum is mental illness, a term that "refers to all mental disorders.

Mental disorders are health conditions that are characterized by alterations in thinking, mood, or behavior (or some combination thereof) associated with distress and/or impaired functioning." This notion of a continuum sees mental health on one end as 'successful mental functioning' compared to mental illness on the other end as 'impaired functioning.'

A key to understanding mental health and mental illness is defining these terms in cultural contexts. The Western notion of mental health divides overall health into three realms; the Eastern notion views health in terms of bodily systems working in harmony. Imbalance or "disharmony" is the cause of illness and results from physical, psychological, nutritional, environmental or spiritual influences tipping that balance.