The potential of first-episode studies in schizophrenia is maximised through systematic epidemiological, clinical and biological comparisons between homogeneous populations of the psychoses.

To conduct prolonged accrual of ‘all’ cases of non-affective and affective psychotic illness on an epidemiologically complete basis.

Within the region covered by Cavan–Monaghan psychiatric service (population 102 810), all putative cases of first-episode psychosis were diagnosed using DSM–IV.

From 1995 to 2000, 69 cases of psychosis were ascertained, the incidence being 2.3-fold lower in females than in males. On resolving the ‘core’ diagnoses of schizophrenia and bipolar disorder, incidence of schizophrenia among women was 7.5-fold lower than among men whereas incidence of bipolar disorder among women was 6.6-fold lower than among men.

This homogeneous population, which eliminates factors associated with urbanicity and minimises confounding factors such as socioeconomic, ethnic and geographical diversity, shows a markedly reduced incidence among females both of schizophrenia and of bipolar disorder.

Childhood hallucinations of voices occur in a variety of contexts and have variable long-term outcomes.

To study the course of experience of voices sequentially over a 3-year period in those with and those without a need for mental health care (patient status).

In a group of 80 children of mean age 12.9 years (s.d.=3.1), of which around 50% were not receiving mental health care, baseline measurement of voice characteristics, voice attributions, psychopathology, stressful life events, coping mechanisms and receipt of professional care were used to predict 3-year course and patient status.

The rate of voice discontinuation over the 3-year period was 60%. Patient status was associated with more perceived influence on behaviour and feelings and more negative affective appraisals in relation to the voices. Predictors of persistence of voices were severity and frequency of the voices, associated anxiety/depression and lack of clear triggers in time and place.

Need for care in the context of experience of voices is associated with appraisal of the voices in terms of intrusiveness and ‘omnipotence’. Persistence of voices is related to voice appraisals, suggesting that experience of voices by children should be the target of specific interventions.