Psychiatric disorders certified on death certificates in an English population.

BACKGROUND: Psychiatric disorders are sometimes certified on death certificates, but seldom selected as the underlying cause of death. The majority of deaths with a certified psychiatric cause are usually omitted from official mortality statistics, which are typically based on the underlying cause alone. AIM: To report on death rates for psychiatric disorders, as certified on death certificates, including all mentioned causes as well as the underlying cause of death. METHOD: Analysis of database including all certified causes of death in 1979-1999, in three time periods defined by coding rule changes. RESULTS: Statistics on the underlying cause of death grossly under-estimated certified psychiatric disorders. For example, in the first period of our study they missed 88% of deaths in which schizophrenia was a certified cause, 98% of affective psychosis, and 96% of depression. Over time, considering all certified causes, age-standardised death rates for schizophrenia declined, those for affective psychosis showed no change, and those for depression and dementia increased. CONCLUSION: The decline in mortality rates for schizophrenia, and the increase for depression and dementia, may reflect real changes over time in disease prevalence at death, although other explanations are possible and are discussed.