section_path: Epidemiology
section_name: Epidemiology
paragraph_text: Epidemiology
  
  Mental illnesses are more common than cancer, diabetes, or heart disease. As of 2021, over 22 percent of all Americans over the age of 18 meet the criteria for having a mental illness. Evidence suggests that 970 million people worldwide have a mental disorder. Major depression ranks third among the top 10 leading causes of disease worldwide. By 2030, it is predicted to become the leading cause of disease worldwide. Over 700 000 thousand people commit suicide every year and around 14 million attempt it. A World Health Organization (WHO) report estimates the global cost of mental illness at nearly $2.5 trillion (two-thirds in indirect costs) in 2010, with a projected increase to over $6 trillion by 2030.
  
  Evidence from the WHO suggests that nearly half of the world's population is affected by mental illness with an impact on their self-esteem, relationships and ability to function in everyday life. An individual's emotional health can impact their physical health. Poor mental health can lead to problems such as the inability to make adequate decisions and substance use disorders.
  
  Good mental health can improve life quality whereas poor mental health can worsen it. According to Richards, Campania, & Muse-Burke, "There is growing evidence that is showing emotional abilities are associated with pro-social behaviors such as stress management and physical health." Their research also concluded that people who lack emotional expression are inclined to anti-social behaviors (e.g., substance use disorder and alcohol use disorder, physical fights, vandalism), which reflects one's mental health and suppressed emotions. Adults and children who face mental illness may experience social stigma, which can exacerbate the issues.