Every illness produces a burden for the person who is affected. Illnesses that cause people to die young (premature mortality) or affect them badly so that they can't live a normal life (see Box 9.1) are said to have a high burden.

Disability is present when a person has a health condition (in this case, mental illness) which impairs their day-to-day functioning in some way. The level of disability experienced depends partly on the seriousness of the impairment, and partly on the social exclusion that further disables people with mental health problems.

From studies in Ethiopia, we know that:

• People with severe mental illness are about three times more likely to die young.
• People with mental illness have high levels of disability.
• Mental illness often starts early in life and, in some people, can recur (come back again and again), or become chronic (persist over a longtime). So mental illness can affect people over a long period of time.

These three factors mean that the burden of mental illness (in terms of mortality and disability) is high.

In a study from Butajira (south-central Ethiopia), researchers found that if you added together the burden from all the illnesses people experience (including infectious disease, maternal disorders and undernutrition), mental illness was responsible for 11.5% of the total burden. Put another way, more than 10% of the burden of all illness in Ethiopia is likely to be due to mental illness.

Mental illness also causes a burden on the family. Family members may have to stop working in order to care for the mentally ill person. They may also worry a lot about the ill person, which puts them at risk of developing mental illness themselves unless they have good support.