There is significant and independent variation of incidence of schizophrenia and other psychoses in terms of sex, age, ethnicity, and place. This confirms that environmental effects at the individual, and perhaps neighborhood level, may interact together and with genetic factors in the etiology of psychosis.

Background. The incidence of schizophrenia in the African-Caribbean population in England is reported to be raised. We sought to clarify whether (a) the rates of other psychotic disorders are increased, (b) whether psychosis is increased in other ethnic minority groups, and (c) whether particular age or gender groups are especially at risk.

BackgroundThere has been a relative dearth of epidemiological research into bipolar affective disorder. Furthermore, incidence studies of bipolar disorder have been predominantly retrospective and most only included hospital admission cases.AimsTo determine the incidence of operationally defined bipolar disorder in three areas of the UK and to investigate any differences in gender and ethnicity.MethodAll patients who contacted mental health services with first-episode psychosis or non-psychotic mania between September 1997 and August 1999 were identified and diagnosed according to ICD–10 criteria. Incidence rates of bipolar affective disorder were standardised for age and stratified by gender and ethnic group across the three areas.ResultsThe incidence rate per 100 000 per year in south-east London was over twice that in Nottingham and Bristol. There was no significant difference in the rates of disorder in men and women. Incidence rates of bipolar disorder in the combined Black and minority ethnic groups in all three areas were significantly higher than those of the comparison White groups.ConclusionsThe incidence of bipolar disorder was higher in south-east London than in the other two areas, and was higher among Black and minority ethnic groups than in the White population.

Higher rates of primary and motor coordination signs are not associated with lower cognitive ability, and are specific to the presence of psychosis.

Implanted pellets that provide a sustained release of [D‐Ala6 Des‐Gly10] LHRH‐ethylamide (GnRHa) were used to induce maturation and ovulation of Southern flounder Paralichthys lethostigma. Of the 12 females whose ovaries contained follicles with a maximum diameter ≥500 μm, 11 ovulated for the first time within 90 h of hormone implantation. Only 1 fish with a maximum follicle diameter less than 500 μm ovulated within 2 wk after implantation. Ovulated eggs were manually stripped from the females and mixed with sperm from several males. Most females were spawned 1 to 3 times on consecutive days with variable fertility. One female was spawned 11 times producing 668,000 eggs. Fertility was evaluated by examining the incubated eggs for early stages of embryonic cleavage. The percentage of fertile eggs in subsamples of incubated eggs ranged from 7–95%. The results indicate that GnRHa implants can be used to induce repeated ovulation in this species. The variability in fertility is discussed in relation to egg quality.