First episode of psychosis in Guam: The role of ethnicity and neighbourhood factors

Abstract

Objective Ethnicity, neighbourhood ethnic density, and four additional neighbourhood factors (urbanicity, crime, voting, and poverty) were examined in relation to the incidence of first episode of psychosis (FEP) in the Pacific Island of Guam. Methods All first contact patients seen at the Guam Department of Mental Health and Substance Abuse (DMHSA) between January 2005 and December 2007 that met DSM‐IV criteria for the diagnosis of a psychotic disorder were included. At the time of the study, DMHSA was the only psychiatric facility in Guam. Results After controlling for age and gender, Chamorros, the indigenous people of Guam, had a standardized incidence rate (IR = 151/100 000 person‐years, 95%CI = 129–173) of FEP over twice that of Whites (IR = 66/100 000 person‐years, 95%CI = 34–99). Individuals from Palau had the highest standardized incidence rate (IR = 832/100 000 person‐years, 95%CI = 581–1083). Increased neighbourhood Chamorro density was associated with decreased incidence of FEP among Chamorro individuals (IRR = 0.11, 95%CI = 0.03–0.43). After controlling for age, gender, ethnicity, and other neighbourhood factors, urbanicity (IRR = 3.82, 95%CI = 1.86–7.81), voting (IRR = 2.06, 95%CI = 1.32–3.20), poverty (IRR = 1.94, 95%CI = 1.40–2.67), and crime (IRR = 1.18, 95%CI = 1.00–1.40) remained statistically associated with FEP incidence. Conclusions The findings add to prior research that suggests that rates of mental health problems are higher in indigenous than in settler communities and are highest for indigenous people who live in neighbourhoods with few other indigenous individuals. Findings also suggest that even on a small island, with only ~150 000 people, urbanicity is associated with FEP. Finally, results are consistent with other research suggesting that the reduction of crime and social adversity can play a positive role in reducing the incidence of first episode psychosis.

Bane or boon regarding urbanicity and psychotic spectrum disorders: a scoping review of current evidence

“…Mixed findings were reported for the FEP and FES populations, with Rosenfarb et al [29 ▪ ] noting that urbanicity was not a significant independent predictor of FEP. Another study found that metropolitan areas in the capital city were high-risk zones for incidence of nonaffective FEP, and this was also associated with a higher density of the migrant population [26 ▪ ].…”

“…The most commonly cited definition of an urban area was based on census or administrative data and classification [11 ▪ –14 ▪ ,15,16 ▪▪ ,17,18 ▪ ,19 ▪ ]. Population density [11 ▪ ,13 ▪ ,20 ▪ ,21 ▪ ,22 ▪▪ ,23 ▪ ,24 ▪ ] and population size in a specific area [13 ▪ ,19 ▪ ,25 ▪ –29 ▪ ] were also common parameters used to delineate the urban-rural divide. Other related parameters included settlement size [11 ▪ ] and dwelling density [11 ▪ ,30 ▪ ], percentage of flats and apartments [20 ▪ ,31 ▪▪ ], and the age of such places of dwelling [31 ▪▪ ].…”

“…Building height [31 ▪▪ ,33] and building density [31 ▪▪ ,32 ▪ ,33] were also features of urbanization thought to contribute to factors that affect the risk of psychosis. The presence of certain facilities and features, such as municipalities, and evidence of urban land use were ways that some studies differentiated between urban and rural areas [13 ▪ ,19 ▪ ,29 ▪ ,31 ▪▪ ]. Distance from main cities or accessibility to cities were used as criterion by some studies [13 ▪ ,31 ▪▪ ,35].…”

“…Four studies focused on patients with first-episode psychosis (FEP) or schizophrenia (FES) [18 ▪ ,25 ▪ ,26 ▪ ,29 ▪ ], one study on patients with chronic high risk of psychosis [27 ▪ ], and one study focused on both FEP and at-risk mental state individuals [40 ▪▪ ]. Five studies were conducted on individuals with psychotic-like experiences (PE) [11 ▪ ,12 ▪ ,23 ▪ ,30 ▪ ,36 ▪ ].…”