Diagnosis change, lithium use and admissions for mania in Edinburgh.

Admissions for mania have risen significantly in Edinburgh since 1970. Differencing was used to remove time trends; this showed that the rise was not accounted for by diagnosis change (from schizophrenia or personality disorder) or by lithium prescription. The contribution of non-specific factors such as admission policy and the experience of trainee psychiatrists deserves evaluation. If this rise continues there will be significant resource implications for the future.