Chapter 1 What are NCDs?

NCDs, also known as chronic diseases, tend to be of long duration and result from a combination of factors: genetic, physiological, behavioural and environmental (1). Since 2000, there has been an increase in the number of deaths arising from NCDs as a proportion of the total number of deaths from all causes (13). Over the same period, NCD-related deaths have increased relative to deaths from communicable causes such as HIV, tuberculosis and malaria. According to WHO, 41 million (75%) of the 55 million global deaths in 2019 were due to NCDs; of these 41 million deaths, 15 million occurred “prematurely” (i.e. in people aged <70 years), and of those 15 million premature deaths, 85% occurred in LMICs (13). Four chronic conditions – cardiovascular diseases, cancers, chronic respiratory diseases and diabetes – account for more than 80% of all premature NCD deaths. In 2019, cardiovascular diseases caused more than 17.9 million deaths globally, followed by cancers (9 million), respiratory diseases (3.9 million) and diabetes (1.6 million) (13). Mental health is also a major contributor to the burden of disease morbidity, but less so in terms of global mortality (14-16).

According to WHO, the NCD burden in the WHO African Region is gradually increasing and is predicted to overtake the burden of mortality and morbidity from communicable diseases by the year 2030 (17). More people from younger age groups will develop NCDs and die from them, even as the management of infectious diseases improves. NCDs are largely preventable; hence, the associated morbidity and mortality can also be prevented.

NCDs, including mental disorders, can interact and amplify each other. WHO has noted that “depression predisposes people to myocardial infarction and diabetes, both of which conversely increase the likelihood of depression”, and that “many risk factors such as low socioeconomic status, alcohol use and stress are common to both mental disorders and other noncommunicable diseases” (18). Physical activity can confer some protection from the development of depression in people of all ages. In addition, exercise can be used to manage symptoms and treat people who already have depression (19-21).