A team of researchers from Sweden and the United States have examined the potential role of the family environment and neighborhood factors on mental health outcomes in a new study published in Journal of Psychiatric Research.
The study includes highly detailed data on over 500,000 children in Sweden and covers a timespan of more than a decade.
A total of 542,195 children were tracked for 11 years for incident internalizing (anxiety and mood) and externalizing (ADHD and conduct) disorders. During the course of the study, 4.8 percent of the children developed a psychiatric disorder.
Key findings from the study include that high neighborhood deprivation was associated with a 2-fold higher risk of conduct disorder, a 40% increased risk of anxiety disorder and a 20% increased risk of mood disorders, after adjustment for individual factors. Moderate neighborhood deprivation was associated with a 30% increased risk of ADHD, after adjustments.
"However, we also found that familial random effects, including both genetic and family environmental factors, accounted for six to eight times as much of the total variation in psychiatric disorders, compared with neighborhood random effects," said Professor Jan Sundquist, who led the research.
"The estimated risks and random effects indicate that children are strongly affected by both their family and neighborhood environments and that the former seems to be more important at a population level," Sundquist continued.
One of the strengths of the study is that it based on data from Sweden's multiple population and health care registers, which are highly complete and valid and, crucially, help to avoid bias from self-reporting.
"With such a rich amount of data at our disposal we have been able carry out a comprehensive study that answers many probing questions about the mental health of young people in Sweden," added Sundquist.
Further research is necessary argue the academics, particularly regarding intervention strategies in early life. In the meantime Sundquist and his team have suggested that their findings should help shape policies to promote mental health by factoring in potential influences from both family and neighborhood environments.