The World Health Organization describes mental health as "a state of well-being in which the individual realizes his or her own abilities, can cope with the normal stresses of life, can work productively and fruitfully, and is able to make a contribution to his or her community".[35] Mental Health is not just the absence of mental illness.[36]

Mental illness is described as 'the spectrum of cognitive, emotional, and behavioral conditions that interfere with social and emotional well-being and the lives and productivity of people. Having a mental illness can seriously impair, temporarily or permanently, the mental functioning of a person. Other terms include: 'mental health problem', 'illness', 'disorder', 'dysfunction'.[37]
Roughly a quarter of all adults 18 and over in the US are considered diagnosable with mental illness. Mental illnesses are the leading cause of disability in the US and Canada. Examples include, schizophrenia, ADHD, major depressive disorder, bipolar disorder, anxiety disorder, post-traumatic stress disorder and autism.[38]

Many teens suffer from mental health issues in response to the pressures of society and social problems they encounter. Some of the key mental health issues seen in teens are: depression, eating disorders, and drug abuse. There are many ways to prevent these health issues from occurring such as communicating well with a teen suffering from mental health issues. Mental health can be treated and be attentive to teens' behavior.[39]

Many factors contribute to mental health problems, including:

• Biological factors, such as genes or brain chemistry
• Life experiences, such as trauma or abuse
• Family history of mental health problems