Annual age-standardised first admission rates from 1969–78 for Scottish mental hospitals were calculated for schizophrenia, paranoid states, reactive psychoses, all affective psychoses, mania, and depressive neuroses. Significant decreases were found in the diagnosis of schizophrenia (P <0.001) and, to a lesser extent, affective psychoses (P <0.01) and depressive neuroses (P <0.02). The incidence of paranoid states, reactive psychoses, and mania did not change significantly.
Several factors possibly contributing to the decline in diagnoses of schizophrenia are discussed, but it is concluded that the figures probably reflect a genuine fall in incidence. The decline in the categories of affective disorder is likely to reflect trends towards increasing provision of community-based care.