Search

The incidence and risk of cycloid psychosis were investigated in the 1947 cohort of the Lundby Study. No male cases were found. For women the incidence rate (per 100 observation years) was 0.016%. The cumulative probability, i.e. risk up to 60 years of age, was 0.7%. These figures are about half of those for schizophrenia in women in the same population. It is concluded that cycloid psychosis constitutes a substantial part of psychotic disorders among women.

Fifty-three patients with acute psychotic disorders (diagnosed according to DSM-III) were treated with thioridazine alone and observed during periods of up to 2 months. The amelioration of paranoid ideas and hallucinations (target symptoms) and of concentration difficulties, disorientation, reduced appetite, and reduced sleep (additional symptoms) was studied by repeated psychopathology ratings (CPRS). The patients were classified as "fast, slow or partial responders" according to the therapeutic effect registered on each target symptom. Paranoid ideas disappeared completely after less than 3 weeks of treatment in 28% of the patients (fast responders) and after more than 3 weeks in 32% (slow responders). Hallucinations disappeared significantly faster than paranoid ideas; 47% of the patients were completely free from hallucinations after less than 2 weeks of treatment (fast responders) and 38% after more than 2 weeks (slow responders). The following factors were significantly correlated to positive treatment effects of thioridazine: 1) diagnosis involving a brief history of psychotic symptoms before admission; 2) a low CPRS score for paranoid ideas on admission; 3) presence of disorientation on admission; 4) normal appetite on admission, and 5) rapidly reached optimal serum concentration of the drug.

The objective of the present study on cycloid psychosis was to describe the incidence and risk in a defined population sample. We therefore re-evaluated specific diagnostic groups in the 1947 cohort of the Lundby Study. Three female cases were identified as cycloid psychosis according to the diagnostic criteria of Leonhard, Perris and Brockington. No men were found. The incidence rate (per 100 observation years) was found to be 0.016% for women. The cumulative probability i.e. risk, up to 60 years of age was calculated to be 0.7%. Incidence rate and risk for cycloid psychosis in women was thus about half of the corresponding values for schizophrenia as described for the same population in a parallel study. We conclude that cases of cycloid psychosis constitute a substantial proportion of female psychotic patients.