Lord Campbell of Croyasked Her Majesty's Government:
What are their estimates of the number of people in the United Kingdom suffering respectively from (a) schizophrenia, (b) manic depression, (c) dementia, and (d) other serious mental illnesses.
§ Lord HenleyThe Government can make no estimate of the number of people suffering from the forms of illness specified, but current scientific evidence suggests that about 7 per cent. of people aged 65 and over suffer from dementia, and there is about a 1 per cent. chance of an individual suffering from schizophrenia, and a similar chance of suffering from manic depressive psychosis, during his or her life. What constitutes "other serious mental illness" is a matter of judgment.
Although there is some variation between research studies, the figures are generally in broad agreement with each other and can be assumed to apply to the United Kingdom as a whole.