Risk of Psychotic-Like Experiences Can Start in Childhood

Summary: The association between exposure to socio-economic and environmental risks for psychosis and psychotic-like experiences are present during late childhood, much earlier than previously believed. The findings could assist in assessing risk factors for the development of schizophrenia later in life.

Source: University of Rochester

It has long been understood that environmental and socio-economic factors – including income disparity, family poverty, and air pollution – increase a person’s risk of developing psychotic-like experiences, such as subtle hallucinations and delusions that can become precursors to a schizophrenia diagnosis later in life.

Research has long focused on young adults but now, thanks to the data from the Adolescent Brain Cognitive Development (ABCD) Study, researchers at the University of Rochester have found these risk factors can be observed in pre-adolescent children.

“These findings could have a major impact on public health initiatives to reduce the risk of psychotic like experiences,” said Abhishek Saxena, a graduate student in the department of Psychology at the University of Rochester and first author of the study recently published in Frontiers in Psychiatry.

“Past research has largely focused on the biological factors that lead to development of schizophrenia spectrum disorders, but we now know that social and environmental factors can also play a large role in the risk and development of schizophrenia. And this research shows these factors impact people starting at a very young age.”

Researchers looked at data collected from 8,000 kids enrolled in the ABCD study. They found that the more urban of an environment a child lived in – proximity to roads, houses with lead paint risks, families in poverty, and income disparity – the greater number of psychotic like experiences they had over a year’s time.

These findings are in line with past research conducted in young adults, but have not been found like this in pre-adolescences.

“It is disconcerting that the association between these exposures and psychotic-like experiences are already present in late childhood,” said David Dodell-Feder, Ph.D., assistant professor of Psychology and Neuroscience and lead author of this study.

“The fact that the impact of these exposures may occur as early as pre-adolescence highlights the importance of early prevention.”

Funding: This research was supported by the National Institute of Mental Health.

Abstract

Explaining the Association Between Urbanicity and Psychotic-Like Experiences in Pre-Adolescence: The Indirect Effect of Urban Exposures

Urban living is a growing worldwide phenomenon with more than two-thirds of people expected to live in cities by 2050.

Although there are many benefits to living in an urban environment, urbanicity has also been associated with deleterious health outcomes, including increased risk for psychotic outcomes particularly when the urban exposure occurs in pre-adolescence. However, the mechanisms underlying this association is unclear.

Here, we utilize one-year follow-up data from a large (N=7,979), nationwide study of pre-adolescence in the United States to clarify why urbanicity (i.e., census-tract population density) might impact psychotic-like experiences (PLE) by looking at the indirect effect of eight candidate urbanicity-related physical (e.g., pollution) and social (e.g., poverty) exposures.

Consistent with other work, we found that of the evaluated exposures related to urbanicity, several were also related to increased number of PLE: PM_2.5, proximity to roads, census-level homes at-risk for exposure to lead paint, census-level poverty, and census-level income-disparity.

These same urban-related exposures were also related to the persistence of PLE after 1 year, but not new onset of PLE. Mediation analysis revealed that a substantial proportion the urbanicity-PLE association (number and persistence) could be explained by PM_2.5 (23–44%), families in poverty (68–93%), and income disparity (67–80%).

Together, these findings suggest that specific urban-related exposures contribute to the existence and maintenance, but not onset of PLE, which might help to explain why those in urban environments are disproportionately at-risk for psychosis and point toward areas for public health intervention.