HMN 2024: Where we grow up may influence mental health, study suggests

Children who move into more deprived neighborhoods are more likely to experience mental health issues as teenagers, according to Canterbury research.

The study, which investigates links between geography, environment and health, was led by Susie Bingyu Deng, a Ph.D. student in the GeoHealth Laboratory at Te Whare W?nanga o Waitaha | University of Canterbury (UC). The research is published in the journal Child Indicators Research.

Deng combined geospatial information with data from the well-known Christchurch Health and Development Study (CHDS) which involves more than 1,200 people born in 1977, allowing her to track the participants’ residential locations over time. She found that where a child grows up can have a significant impact on their future mental health.

Children who moved from a relatively well-off area to a more deprived neighborhood before the age of 16 were almost three times as likely to suffer from depression in adolescence compared to those who had a stable childhood in an affluent area, according to her results.

“This downward trajectory from least deprived to most deprived may lead to higher risks of depression in teenage years, although the association does not appear to persist into adulthood,” Deng says.

Deng, who studied in China before moving to New Zealand in 2019 to start her master’s degree at UC, says longitudinal studies can provide robust evidence about the impact of environmental factors on their mental health.

“The CHDS study has been running for more than 40 years so the data available is quite powerful. I would love to incorporate more environmental factors, such as noise pollution and air pollution, in my future research.”

In a separate study using similar data, Deng identified several factors, such as childhood family socioeconomic status, exposure to adversity, and family dysfunction, that may lead children to be more vulnerable to frequent household moves.

“When considering the adverse effects of moving to more deprived areas on mental health observed in the earlier study, these populations deserve focused attention to mitigate potential mental health risks,” Deng says.

In order to reveal how socioeconomic status affects health outcomes over time, she constructed a metric for area-level deprivation in Aotearoa New Zealand for the years 1981, 1986 and 1991 using census and geographical information. She found that deprivation worsened across the country over this decade:

Seventy percent of areas had worsening levels of deprivation over the time period, (based on measures such as unemployment and non-home ownership) and only 3% of the areas studied were less deprived.

The Far North, central and eastern areas of the North Island, along with the West Coast of the South Island, were the most consistently deprived areas throughout the decade.

Deng says accurate information on area-level deprivation is important because these metrics are used extensively in the social and health sciences for research and policy development, and in funding decisions for schools and health organizations in order to target areas of high need.

“This longitudinal metric opens up new possibilities for future studies in New Zealand to gain a better understanding of how significant socioeconomic transformations impact individual health and how neighborhood deprivation affects health outcomes over time.”