Mental health: introduction

What is mental health?

Two aspects of mental health are considered in these web pages: mental health problems (a negative dimension) and mental wellbeing (a positive dimension). Mental health problems range from mild sub-clinical conditions to severe and enduring clinically diagnosed mental illness. Mental wellbeing is more than the absence of mental health problems: it may include life satisfaction, a sense of control, having a purpose in life, a sense of belonging and positive relationships with others.

The field of mental health is full of disputed terminology with many different definitions, influenced by age, class and gender, people's experiences and expectations, and cultural and religious beliefs. Mental health influences how we think and feel, about ourselves and others, and how we interpret events. It affects our capacity to learn, to communicate and to form, sustain and end relationships. It also influences our ability to cope with change, transition and life events. See 'Concepts and Definitions' briefing paper  (380Kb) for further information.

Mental wellbeing

There is greater variety in definitions of mental wellbeing than mental health problems. However, most tend to emphasise that mental wellbeing includes aspects of subjective wellbeing: ‘affect’ (the subjective experience of happiness), life satisfaction, and psychological wellbeing (such as a sense of control, having a purpose in life, a sense of belonging and positive relationships with others). It is more than the absence of mental health problems. According to the Mental Health Foundation, individuals with good mental wellbeing:

  • develop emotionally, creatively, intellectually and spiritually
  • initiate, develop and sustain mutually satisfying personal relationships
  • face problems, resolve them and learn from them and are able to cope with adversities (i.e. show resilience)
  • have the capacity to contribute to family and other social networks, local community and society
  • have a positive sense of well-being
  • have individual resources including self-esteem, optimism, and sense of mastery and coherence
  • are confident and assertive
  • are aware of others and empathise with them
  • use and enjoy solitude
  • play and have fun
  • laugh, both at themselves and at the world.

Mental health problems

Mental health problems cover a continuum from symptoms at a sub-clinical threshold which interfere with emotional, cognitive or social function, to the most severe clinically diagnosed mental illnesses.  Examples include common mental health problems such as depression and anxiety, and severe and enduring mental health problems such as schizophrenia.

Symptoms of mental health problems at a sub-clinical level interfere with a person's cognitive, emotional or social abilities such that their daily living can be impacted, but to a lesser extent than a mental illness. They are more common, usually less severe and are of shorter duration than mental illnesses, but may develop into a mental illness.  The point at which a mental health problem becomes an illness is not clear-cut, but is usually judged on the basis of severity and duration of the symptoms.

Mental illness refers to a diagnosable illness defined through recognised classifications such as the WHO International Classification of Disease (ICD10) or the Diagnostic Statistical Manual Version IV produced by the American Psychiatric Association, 1994 (see Key references and evidence). 

They have traditionally been divided in a variety of ways including distinguishing between:

  • Organic (identifiable brain malfunction) versus functional (not due to structural abnormalities of the brain)
  • Neurosis (severe forms of normal experiences such a low mood, anxiety) versus psychosis (severe distortion of a person's perception of reality).

Terminology, however, varies considerably across professions and cultures, and in different information sources the definition may include or exclude different conditions.

Mental health as a public health issue

Mental health is an integral part of public health and is as important as physical health to the overall wellbeing of individuals, communities and societies. Indeed, it has been said that 'there is no health without mental health' and everyone has mental health needs (see Mental health: new understanding, new hope).

Mental wellbeing is important for individuals as well as for society. At an individual level, it enables people to realise their intellectual and emotional potential and to find and fulfil their roles in social, school and working life. At society level, mental wellbeing is a resource for social cohesion and better social and economic welfare (Keyes 2002   (233Kb)). This is underpinned by a wealth of evidence that "mental health is produced socially: the presence or absence of mental health is above all a social indicator and therefore requires social, as well as individual solutions" (Friedli, 2009  (459Kb)).

Mental health problems (ranging from mild sub-clinical symptoms to clinically diagnosed illness) cause a large and increasing burden that contributes to high costs to societies, long-lasting disability, increased mortality and enormous human suffering. Some of the major mental health problems perceived to be public health issues are depression, anxiety, substance misuse disorders, psychosis and dementia. It is predicted by The World Health Organization (WHO) that by 2030 depression will be second only to HIV/AIDS as an international health burden (Mathers and Loncar, 2005  (1.2Mb)).