Social Adversities and Inequities in Psychosis

Abstract

Ethnic minorities have higher risk of psychotic disorders such as schizophrenia. Available evidence indicates that social adversities such as discrimination and parental loss play a role in this increased risk. This dissertation takes a multi-method approach to: 1) quantitatively investigate whether two social adversities, major discrimination and early parental death, help explain excess risk of psychotic disorders among ethnic minorities, and 2) qualitatively describe how individuals with psychotic disorders perceive the role of social adversities in their illness. Quantitative analyses used the European Network of National Schizophrenia Networks Studying Gene-Environment Interactions population-based case-control study from 16 catchment sites across six countries. Multivariable mixed-effects logistic regression models were used to estimate the associations between discrimination and psychosis and parental death and psychosis. Stratified analyses were used to explore differences by ethnic minority status. Qualitative analyses used 20 semi-structured, in-depth interviews of patients with psychotic disorders receiving treatment at an outpatient psychiatric clinic. Modified Grounded Theory was used to understand how early social adversities influenced later family interactions. Experiencing pervasive discrimination was three times more common among ethnic minorities than the ethnic majority, and associated with 1.8-fold greater odds of psychosis compared to those with no discrimination. When stratified, this association held for ethnic minorities but not the ethnic majority. Experiencing early parental death was twice as common among ethnic minorities than the ethnic majority. Individuals who experienced early maternal death had 2.3-fold greater odds and those who experienced multiple early parental deaths had 4.4-fold greater odds of psychosis compared to those with no early parental death. When stratified, ethnic minorities had a much stronger association for multiple deaths than the ethnic majority. Qualitatively, patients with psychotic disorders who described early adversities of childhood abuse and/or unstable homes tended to explicitly link these experiences to limited family interactions, including perceived absence of support for their illness. This differed from patients who did not mention early adversities and described positive family interactions and perceived supportive involvement in their illness. These findings advance our understanding of the role of social adversities in psychosis, including helping to explain the excess risk among ethnic minorities.