World health report

Conquering suffering, enriching humanity

Mental and neurological disorders

The impact of mental and neurological disorders on society is likely to become more and more profound in future years. Already, many hundreds of millions of people are affected by some form of mental disorder, from the relatively minor to the incurable and life-threatening; many individuals suffer from several simultaneously.

Epilepsy, the most common neurological condition, afflicts 40 million people. An estimated 45 million have schizophrenia; an increase in its prevalence is expected due to a rise in the proportion of the population moving into the age group at risk. Given its chronic nature in the majority of cases, schizophrenia imposes a burden not only on the sufferers but also on their families. In many developing countries, the supply of essential drugs to treat this condition cannot always be maintained.

Some 29 million suffer from dementia, of which Alzheimer disease is the most common form. Global population ageing will inevitably result in huge increases in the number of cases of dementia. The risk of developing the condition rises steeply with age in people over 60; the possibilities for prevention and treatment are limited. Projections suggest that Africa, Asia and Latin America together could have more than 80 million people with dementia by the year 2025.

Mood disorders (including depression) are estimated to affect some 340 million people at any given time. In the United States of America alone, the yearly cost of depression is estimated at US$44 000 million, equal to the total cost of all cardiovascular diseases.

Tobacco is estimated to cause three million deaths a year primarily from lung cancer and circulatory diseases. The use of alcohol, illicit drugs and other psycho-active substances causes at least 123 000 deaths annually. Alcohol is also implicated in crime, violence, marital breakdown and major losses in industrial productivity. Amfetamines and other psychostimulant drugs are increasingly being used worldwide; in many countries drug injection is becoming more common.