According to The Lancet "Series on Global Mental Health", neuropsychiatric disorders make up 14% of the global disease burden. Because mental illness is so debilitating, it contributes more to the global burden than heart disease, stroke, or cancer. Neuropsychiatric disorders include depression, psychoses like anxiety, bipolar disorder, schizophrenia, eating disorders, Alzheimer's disease, in addition to substance and alcohol use disorders. Professor Martin Prince of the London King's College Institute of Psychiatry claims that mental illness can increase the likelihood of developing and amplifying a wide range of physical illnesses. He explains that neuropsychiatric disorders are commonly accompanied by communicable and non-communicable diseases that complicate treatment and can lead to poor outcomes, including a higher risk of death. More research needs to be done to better understand the link between mental and physical health and the potential for mental health intervention to improve physical well being.
Very little is known about the impact of mental disorders on physical illness in low and middle income countries. Eighty percent of non-communicable disease deaths occur in these countries and mental healthcare budgets are too low to measure the impact of neuropsychiatric disorders. Professor Prince claims that "Mental health awareness needs to be integrated into all elements of health and social policy..."