Mental health, as defined by the Public Health Agency of Canada,[7] is an individual's capacity to feel, think, and act in ways to achieve a better quality of life while respecting personal, social, and cultural boundaries.[8] Impairment of any of these are risk factor for mental disorders, or mental illnesses,[9] which are a component of mental health. In 2019, about 970 million people worldwide suffered from a mental disorder, with anxiety and depression being the most common. The number of people suffering from mental disorders has risen significantly throughout the years.[10] Mental disorders are defined as health conditions that affect and alter cognitive functioning, emotional responses, and behavior associated with distress and/or impaired functioning.[11][12] The ICD-11 is the global standard used to diagnose, treat, research, and report various mental disorders.[13][14] In the United States, the DSM-5 is used as the classification system of mental disorders.[15]
Mental health is associated with a number of lifestyle factors such as diet, exercise, stress, drug abuse, social connections and interactions.[15][16] Psychiatrists, psychologists, licensed professional clinical counselors, social workers, nurse practitioners, and family physicians can help manage mental illness with treatments such as therapy, counseling, and medication.