Does ethnicity have an impact on duration of untreated psychoses: A retrospective study in Singapore

Background: Some studies have suggested ethnicity as being one of the causes leading to a longer duration of untreated psychosis (DUP) in first episode psychosis. Aim: We sought to investigate this issue, in a large cohort of patients with a first episode of psychosis, in Singapore. Method: In this naturalistic retrospective study, 794 patients accepted into Early Psychosis Intervention Programme (EPIP) services in Singapore were recruited. Diagnosis was made based on SCID 1 (Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV), Axis I Disorders). Information about DUP and sociodemographic characteristics was collected from patients and relatives. Positive and Negative Symptom Scale (PANSS) and Global Assessment of Functioning (GAF) Scale were used as tools to assess the severity of symptoms and functioning of the patient, respectively, at baseline, 3, 6, 12 and 24 months. Results: The mean and 50th quantile (median) of DUP for this sample were 14.2 and 6, respectively. The mean and median DUP were higher among Indians than in the other ethnic groups. After adjusting for demographic variables, Indian ethnicity was significantly associated with higher median and 75th Percentile DUP than Chinese. Secondary and tertiary education and diagnosis of affective psychosis and brief psychotic disorder (vs. schizophrenia spectrum and delusional disorder) were also significantly associated with lower mean, median and 75th percentile DUP symptoms. Increase in age was significantly associated with higher mean, median and 75th percentile DUP while married and separated/divorced (vs. single) was significantly associated with lower mean and 75th percentile DUP. Conclusion: This study found a positive correlation between certain ethnic groups and DUP. Indian ethnicity, older age, single, lower education and patients diagnosed with schizophrenia spectrum and delusional disorders were more likely to be associated with longer DUP.