The effect of ethnicity and immigration on treatment resistance in schizophrenia

• Published in: Comprehensive psychiatry Vol. 89; pp. 28 - 32
• Main Authors: Bani-Fatemi, Ali, Tasmim, Samia, Graff, Ariel, Gerretsen, Philip, Dada, Oluwagbenga O., Kennedy, James L., Hettige, Nuwan, Zai, Clement, de Jesus, Danilo, de Bartolomeis, Andrea, De Luca, Vincenzo
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.02.2019; Elsevier Limited; Elsevier
• Subjects: Adult; Antipsychotic Agents - therapeutic use; Antipsychotics; Canada; Cross-Sectional Studies; Drug dosages; Emigrants and Immigrants - psychology; Ethnic Groups - psychology; Ethnicity; European Continental Ancestry Group - psychology; Families & family life; Female; Genealogy; Humans; Immigration policy; Logistic Models; Male; Mental health; Middle Aged; Migration; Minority & ethnic groups; Noncitizens; Patient Acceptance of Health Care - ethnology; Patient Acceptance of Health Care - psychology; Patients; Polypharmacy; Psychotropic drugs; Schizophrenia; Schizophrenia - ethnology; Schizophrenic Psychology; Self Report; Substance abuse treatment; Treatment resistance; Canada; United States > US; Schizophrenia; Antipsychotics; Treatment resistance; Ethnicity; Migration
• ISSN: 0010-440X; 1532-8384
• DOI: 10.1016/j.comppsych.2018.12.003

Treatment resistance is a common issue among schizophrenia patients undergoing antipsychotic treatment. According to the American Psychiatric Association (APA) guidelines, treatment-resistant status is defined as little or no symptom reduction to at least two antipsychotics at a therapeutic dose for a trial of at least six weeks. The aim of the current study is to determine whether ethnicity and migration are associated with treatment resistance. In a sample of 251 participants with schizophrenia spectrum disorders, we conducted cross-sectional assessments to collect information regarding self-identified ethnicity, immigration and treatment history. Ancestry was identified using 292 markers overlapping with the HapMap project. Using a regression analysis, we tested whether a history of migration, ethnicity or genetic ancestry were predictive of treatment resistance. Our logistic regression model revealed no significant association between immigration (OR = 0.04; 95%CI = 0.35–3.07; p = 0.93) and treatment resistant schizophrenia. White Europeans did not show significant association with resistance status regardless of whether ethnicity was determined by self-report (OR = 1.89; 95%CI = 0.89–4.20; p = 0.105) or genetic analysis (OR = −0.73; 95%CI = −0.18–2.97; p = 0.667). Neither ethnicity nor migrant status was significantly associated with treatment resistance in this Canadian study. However, these conclusions are limited by the small sample size of our investigation. •10-30% of schizophrenia patients are treatment resistant and up to a further 30% are partially responsive to the treatments.•Neither self-report ethnicity nor migration was significantly correlated with treatment resistance.•Genetically determined Asian ancestry was associated with resistance status.