Research suggests that urbanicity and lower socio-economic status are risk factors for psychosis.

To calculate the incidence and period prevalence of patients admitted with psychosis in Malta, and to examine differences between districts. To date, this is the first study of its kind carried out in the Maltese Islands.

One year prospective cross-sectional study, including all ICD-10 psychosis patients admitted to any one of the three psychiatric hospitals (n=180).

Incidence of hospital admissions due to psychosis was 26.0 at risk per year per 100, 000 population. Period prevalence for 6 years was 41.9 per 100,000 person-years. Highest incidence: Southern-Harbour area (32.1, CI=31.9–32.3), and lowest incidence: Western District (20.1, CI=19.9–20.2). The period prevalence was highest in Gozo District (63.9, CI=63.2–64.7). 5.2% of participants were irregular migrants, having an approximate estimate for incidence of psychosis of 400 per 100,000 person years at risk.

The high incidence of psychosis may be explained by the fact that Malta is the eighth most densely populated country worldwide. The district with the lowest socio-economic groups were found to have the highest incidence of psychosis, followed by the most densely populated district. Cultural factors, small genetic pool or readily available services could account for the high period prevalence in the Gozo district -a more rural area. Higher education in the Western district area could partially explain the lower incidence. Multiple Stressors and trauma may partially be the reasons for the much higher incidence rate in the irregular immigrant group.