Childhood Exposure to Air Pollution Linked to Psychiatric Symptoms in Young Adulthood

Exposure to air pollution in childhood may be a risk factor for poorer mental health in young adulthood, a study in JAMA Network Open has found. The study suggests that exposure to outdoor nitrogen oxides (NOx) such as those emitted from vehicles and industry may increase the risk of symptoms of psychiatric illness as much as childhood exposure to lead.

“Given the ubiquity of this exposure, air pollution could represent a meaningful contributor to the global burden of psychiatric illness, particularly in poor air-quality regions,” wrote Aaron Reuben, M.E.M., of Duke University, Louise Arseneault, Ph.D., of Kings College London, and colleagues.

The researchers analyzed data from 2,039 young adults in the Environmental-Risk Longitudinal Twin Study, a population-based cohort study of children born from January 1, 1994, to December 4, 1995, in England and Wales. The study followed participants until they were 18 years old, at which time the participants were interviewed about past-year symptoms of mental disorder. Reuben and colleagues combined symptoms associated with 10 psychiatric disorders to create a single measure of mental health, the psychopathology factor (p-factor). They also assessed the young adults’ internalizing symptoms (depression, generalized anxiety, posttraumatic stress, and disordered eating), externalizing symptoms (substance use, oppositional behavior, and attention-deficit/hyperactivity), and symptoms of thought disorders (delusions, hallucinations, and unusual thoughts and feelings).

By using high-quality air dispersion models and data provided by the U.K. National Atmospheric Emissions Inventory and the Imperial College’s U.K. road-traffic emissions inventory, Reuben and colleagues were able to determine the levels of NOx around the participants’ homes when the participants were 10 and 18 years old.

The researchers found that those with the greater exposure to NOx as children had higher p-factors and were more likely to have internalizing symptoms, external symptoms, and symptoms of disordered thought at age 18 than those with lower exposure, even after adjusting for other mental health risk factors such as lower socioeconomic status and a family history of mental illness.

Reuben and colleagues noted that air pollution may affect central nervous system (CNS) development.

“Overall, robust but nonspecific elevations in psychopathology after air pollution exposure reflect the findings that air pollutants can effect diverse and diffuse CNS developmental impairments, depending on the pollutant mix, duration of exposure, age of exposure, and pathway to the brain,” they wrote.

For related information, see the Psychiatric Services article “Air Pollutants and Daily Hospital Admissions for Psychiatric Care: A Review.”

(Image: iStock/Hung_Chung_Chih)

---

Interested in Loan Repayment Program? NHSC Welcomes Applicants

The deadline to submit applications for the National Health Service Corps (NHSC) Loan Repayment Program has been extended until Thursday, May 27 at 7:30 p.m. ET. Learn more about your eligibility and the application process here.

LEARN MORE

---

Don't miss out! To learn about newly posted articles in Psychiatric News, please sign up here.

Follow Psychiatric News on Twitter!

Imaging Study Points to Pathway Linking Child Abuse With Mental Illness

Childhood maltreatment is known to be associated with changes in brain structure and with psychopathology, but more needs to be learned about the biological connection between the two.

A longitudinal study of 51 adolescents with a history of abuse now suggests that changes in cortical thickness are associated with increased risk of internalizing and externalizing symptoms. The findings by Daniel Busso, Ed.D., of the Harvard Graduate School of Education and colleagues were published in the Journal of Child and Adolescent Psychiatry.

Busso and colleagues first assessed the adolescents for abuse exposure, then conducted structural magnetic resonance imaging scans and diagnostic interviews with the youth 14 months later. About two years later, the participants completed additional mental health assessments.

The researchers found that child abuse was associated with reduced cortical thickness in several regions of the lateral and medial prefrontal cortex and temporal cortex. The thickness of the left and right parahippocampal gyrus predicted antisocial behavior symptoms, and the thickness of the middle temporal gyrus predicted general anxiety symptoms. The authors found no association between abuse and volume of the amygdala or hippocampus.

“Our findings reflect the impact of abuse on cortico-limbic areas implicated previously in behavioral and emotional control functions,” Busso and colleagues concluded. “The medial temporal lobe and interconnected limbic structures are involved in the pathophysiology of both internalizing and externalizing psychopathology, including ODD/CD [oppositional defiant disorder/conduct disorder], ASB [antisocial behavior], and depression, potentially because they reflect underlying deficits in emotion processing or regulation that are relevant to these disorders.”

For more information about adolescent brain development, see the Psychiatric News article “NIH Kicks Off National Adolescent Brain Development Study.”

(Image: iStock/Semnic)

Early Intervention in At-Risk Children Can Reduce Psychiatric Problems in Adulthood.

Early and sustained intervention of children with conduct problems can lower the chances that those problems will extend into adulthood, reports a new study published in AJP in Advance titled “Impact of Early Intervention on Psychopathology, Crime, and Well-Being at Age 25.”

Known as Fast Track, this project enrolled kindergarteners who displayed aggressive or disruptive behaviors into a multi-component, 10-year, manualized program aimed at instilling social competencies that would extend throughout their lifetimes "through social skills training, parent behavior-management training with home visiting, peer coaching, reading tutoring, and classroom social-emotional curricula," the researchers noted. The program took place in four communities: Durham, N.C., Nashville, Seattle, and rural Pennsylvania. A similar set of at-risk children receiving only the standard interventions in their community were followed as a control group.

There has not been much evidence showing that behavioral improvements in children translate into adulthood, but so far, the Fast Track study seems to suggests that such an intervention can have an impact, finding that while 69% of the adults in the control group displaying at least one psychiatric problem at age 25, only 59% of Fast Track participants displayed a psychiatric problem at the same age. Fast Track participants also displayed decreased rates of substance abuse crimes, violent crimes, and risky sexual behavior compared with controls, as well as higher levels of happiness and well-being.

“This shows that we can go a full eight years after last seeing these children and still see reductions in the rates of problem outcomes for this group as young adults,” said study author Kenneth Dodge, Ph.D., director of the Center for Child and Family Policy at Duke University.

The improvements in behavior were consistent among each of the 13 subgroups assessed (including those defined by gender, ethnicity, study site, etc.), demonstrating that this approach has potential for a wide range of children and risk levels.

To read about a promising early-intervention effort with children in Australia, known as Headspace, see the Psychiatric News article “Australian Youth Get a ‘Soft Entry’ Into Mental Health System.”

(image: PathDoc/Shutterstock)

Stressful Events Linked to Smaller Brain Size

Adverse life events can reduce the brain’s gray matter, according to a study published online January 2 in Biological Psychiatry. Yale University researchers performed MRI scans on 103 healthy individuals, aged 18 to 48, and interviewed them about stressful events and adversity in their lives, like job loss, divorce, or the death of a loved one.

Both cumulative and recent stress were associated with reductions in several parts of the brain, especially the medial prefrontal cortex and the limbic regions. These areas are involved in stress, emotion and reward regulation, and impulse control and may be involved in depression, addiction, and other stress-related psychopathology. “The accumulation of stressful life events may make it more challenging for these individuals to deal with future stress, particularly if the next demanding event requires effortful control, emotion regulation, or integrated social processing to overcome it,” said lead author Emily Ansell, M.D., an assistant professor of psychiatry at Yale, in a statement.

Read more about the relationship between stress and brain changes in Psychiatric News.

(Image : Argus/Shutterstock.com)