Growing up in an impoverished urban neighborhood more than doubles your chances over the average person of developing a psychosis-spectrum disorder by middle adulthood, according to a new study.
Researchers, who followed nearly 4,000 families for more than three decades, say the results suggest that intervention through social policies and investment in neighborhood improvements, as well as identifying those most in need of help by observing certain child behaviors, could prevent future debilitating illnesses and the societal and personal costs associated with them.
“One important message to take from this study is that the stresses and chronic day-to-day challenges of living in under-resourced or impoverished communities can undermine the well-being of individuals whether they seem to have a vulnerability or not,” says lead author Paul D. Hastings, professor of psychology at the University of California, Davis.
Hastings explains that while heredity is a major factor in predicting schizophrenia, bipolar disorder, and other disorders involving psychoses—that is, breaks with reality, like delusional beliefs and hallucinations—the new study provides clear evidence that environmental factors experienced in childhood also affect future mental health.
Adversity and development
The origins of the Concordia Longitudinal Research Project date back to the 1970s, when the initial researchers, Jane Ledingham of the University of Ottawa and Alex Schwartzman of Concordia University, sought to test existing theories on the roles of early adversity and children’s social characteristics on the development of psychiatric disorders.
The researchers followed families living in low-income urban communities in French-speaking parts of Montréal, Québec, comprising, in the end, nearly 11,000 individuals. The researchers used peer reports of behavior at school to assess children’s aggression, withdrawal, and likeability.
Beginning in the mid-2000s, Hastings, Schwartzman, and their colleagues began reviewing the previous three decades of individual medical records for the family members and census data on neighborhood economic conditions. On average the children were about 10 years old at the start of the study, and researchers followed them until they were 40. During the same period, their parents aged from their late 30s into their late 60s.
Residents of Québec receive government-funded health care and researchers analyzed numerically coded records of the subject families in order to identify psychiatric diagnoses. Because the researchers were able to identify parental diagnoses in the sample studied, their analyses could predict the children’s future prevalence of psychiatric disorders above and beyond what would result from heredity, Hastings says.
More than 6 percent of the children had developed schizophrenia, bipolar disorder with psychosis, and other psychosis-spectrum disorders by middle-adulthood, and those children who grew up in the most economically disadvantaged neighborhoods had the greatest likelihood of being diagnosed with schizophrenia or bipolar disorder.
The study also found childhood social behaviors to be strong predictors of psychotic illnesses. In particular, children whose peers evaluated them as both highly aggressive and highly withdrawn were likely to develop psychosis-spectrum disorders if they also grew up in more impoverished neighborhoods.
“Disorders like schizophrenia really become chronic diseases that require constant care, management, and maintenance.”
“This hypothesis was one of the reasons that Dr. Schwartzman and Dr. Ledingham started this study in 1976, and to my knowledge, this is the first prospective longitudinal study that shows that these combined characteristics of aggression and withdrawal predict future psychosis spectrum disorders,” Hastings says.
The findings suggest that intervention with young children exhibiting these complex patterns of antisocial behavior could improve outcomes, he says.
The study could also help improve efforts to predict, identify, and prevent serious mental illnesses, Hastings adds.
“Once psychosis spectrum disorders take hold they are difficult to treat. It is kind of like ALS (amyotrophic lateral sclerosis) and similar illnesses. Disorders like schizophrenia really become chronic diseases that require constant care, management, and maintenance.
“Reducing them by improving neighborhood conditions for all families in economically disadvantaged communities, and working directly with the families of children showing risky profiles of behavior, could improve the quality of people’s lives and markedly reduce health care costs,” he says.
Additional authors from Concordia University, San Diego State University, and the University of Ottawa contributed to the study, which appears in Development and Psychopathology.
Funding for the study came from the Canadian Institutes of Health Research; the University of California, Davis; Concordia University, the Commission d’accès à l’information of Québec; the Québec Health Insurance Agency; and the Ministries of Health and Education of Québec.
Source: UC Davis