A recent JAMA Psychiatry study determines whether residential moves during childhood and varying levels of neighborhood income deprivation are correlated with depression risk in adulthood.

Study: Changing Neighborhood Income Deprivation Over Time, Moving in Childhood, and Adult Risk of Depression. Image Credit: Studio Romantic / Shutterstock.com

Mental health issues and early life experiences

The global economic burden associated with mental illness is predicted to increase to $6 trillion USD by 2030, which surpasses the combined costs of diabetes, cancer, and chronic respiratory diseases. The causes of mental illnesses are multifaceted and may include socioeconomic, biological, and psychological factors.

Income and neighborhood-level characteristics can positively or negatively affect an individual’s health. Positive social interactions, for example, can give individuals a sense of control over their surroundings, reducing the risk of depression.

Adulthood depression and childhood deprivation are positively associated. Children who frequently move residences are often at a greater risk of mental health issues later in life, which could be due to disruptions in social networks, family routines, and emotional relationships. Thus, childhood residential mobility may serve as a potential risk factor for mental health disorders later in life.

About the study

The current study utilized national Danish registers to test the hypothesis that greater residential movement during childhood and higher neighborhood-level income deprivation is associated with a greater risk of depression in adulthood.

The study cohort comprised all Danish citizens born between January 1, 1982, and December 31, 2003, who resided in Denmark during the first 15 years of life. These individuals were monitored until receiving a depression diagnosis, emigration, death, or December 31, 2018.

Exposure measures included a mean income deprivation index for the entire childhood and a neighborhood income deprivation index at the place of residence for the same duration. Individuals were classified a’ ‘staye’s’ o’ ‘mover’,’ depending on whether they stayed in the same data zone during their entire childhood.

Study findings

The study cohort comprised 1,096,916 individuals, 51.4% of whom were male. During the follow-up period, 35,098 individuals received a diagnosis of depression, 32.4% of whom were male and 67.6% female.
A significant association was observed between a higher incidence of depression in adulthood and educational level, employment status, and lower parental income after controlling for individual-level risk factors for depression. An increased risk of depression in adulthood was also associated with young maternal age and, to a lesser extent, paternal age.

Moving during childhood was significantly associated with higher rates of depression in adulthood as compared to those who did not move. If a child moved more than once between 10 and 15 years of age, the risk of depression in adulthood was 1.61 times higher. The effect of moving on adulthood depression was persistent, irrespective of staying in a more- or less-deprived neighborhood during childhood.

A small but consistent association was observed between depression risk and neighborhood income deprivation at all ages. After individual-level adjustment, the risk was slightly attenuated.

Overall, an increase of 2% in the incidence of depression was observed for every standard deviation increase in income deprivation during the first 15 years of life. Results were similar when censoring for schizophrenia spectrum disorder or substance use disorders.

When the deprivation index was split into quintiles, interesting heterogeneities were noted. For example, if an individual was born in an area of lowest income deprivation and resided in an area of moderate deprivation at 15 years of age, the depression risk was higher by 18%. Conversely, the reverse pattern of lower depression risk was observed in those born in more deprived neighborhoods but moved to slightly higher-income neighborhoods by 15 years of age.

Conclusions

The study findings confirm the protective role of a settled home environment in childhood against depression in adulthood. Thus, policies should be devised to create and support settled childhoods.

A key limitation of the sample used in the current study is the biased representation of patients at the more severe end of the depression spectrum. However, the researchers hypothesize weaker associations in cases of milder forms of depression. Furthermore, imperfect measurements of covariates or imperfectly characterizing neighborhoods could lead to some degree of undetected residual confounding.

An additional limitation is the Danish registers’ inability to capture the complexity of blended families. For example, in family breakups, a child may have separate maternal and paternal homes, between which they alternate frequently, but the register will only record one address for each child.