A recent npj Science of Learning study used regression models to estimate the relationship between parental mental disorders and child school performance, adjusting for genetic and social confounders.
Study: The association between parental internalizing disorders and child school performance. Image Credit: DraganaGordic/Shutterstock.com
Background
Parents arguably play the most important role in children's lives, especially during their formative years. Despite the high prevalence of anxiety and depression, little is known about how these parental disorders correlate with child school performance in Norway. Most existing studies suffer from a confounding issues problem.
Existing studies in this literature fall under two broad themes. One area focuses on severe mental disorders like schizophrenia and bipolar disorder. This area shows that parental mental disorders negatively affect children's school performance and are associated with a greater probability of dropping out of compulsory education.
A second area of research explores maternal depression and its effects on child outcomes.
Overall, papers in this area show that self-reported maternal depression predicted lower school performance. Although correlation has been well established, whether parental mental disorders have a causal effect on child school performance is yet to be ascertained.
About the study
To address the aforementioned gap in the literature, the current study investigated the association between child school performance and parental mental disorders. Population-wide diagnostic data with a genetically informed design was used for this study.
There were three main goals of this study. The first was to detect the fraction of children with a parent diagnosed with internalizing disorder (anxiety and depression). Second, to test the strength of the relationship pre and post-adjusting for known observed confounders.
Third, to additionally adjust for unobserved time-constant confounders, including genetic influences, using data from adoptees and siblings.
The population sample was based on the population register of Norway. Children born between 1992 and 2002, participating in compulsory education, and aged between 15 and 17 years were considered.
Further, the children needed at least one known parent to be included in this study. The standardized grade point average (GPA) at the end of compulsory education was considered to be a proxy for school performance. Associations were also considered in samples of differentially affected siblings and adoptees.
Key findings
18.8% of children had a parent with an internalizing disorder diagnosis in the last three years of primary education. The average annual prevalence for any parental mental disorder was 14.4%. This included mental health disorders in either the mother, the father, or both.
The results documented here are consistent with prior studies in that parental internalization is strongly associated with school performance. However, the association was significantly weaker when comparing siblings who were not exposed to mental disorders in parents equally.
The association disappeared on considering adopted children. The confounding adjustments were consistent with a causal effect of parental mental disorders on child school performance. It is unclear whether the effects are large enough with regard to the intergenerational transfer of social disadvantage.
Previous research has conjectured that the relationship between parental mental illness and child school performance is affected by genetic confounding. In this study, similar associations have been documented after adjusting for genetic confounders. However, in the adoptee analysis, no statistically significant association was found.
The sibling model reveals a weaker association when the child experiences parental mental disorders in lower secondary school (aged 14–16).
This effect is absent in children aged 11–13 years. It must be noted that parental internalizing disorders are pervasive, which means even a small initial effect can have lasting consequences.
Strengths and limitations
This study has several notable strengths, including controlling for a range of potential sources of confounding, such as parental income and education levels.
To remove the genetic pathway between parental disorders and offspring educational success, only foreign-born adoptee children were included.
The sibling model has some limitations. The mental illness would have usually started long before the diagnosis. Both depression and anxiety are persistent phenomena where cyclical patterns and relapse are normal.
Highly persistent and frequent parental mental disorders are less likely to affect different siblings differently. In light of this, the sibling model should be interpreted as a lower bound of an acute effect.
Further, it could not be assessed whether the internalizing disorder was remitted. It was assumed that a year without a diagnosis indicates no disease/remission, which could lead to the false classification of parents experiencing mental illness but not seeking medical help.
Lastly, reverse causality could not be ruled out, where child school performance led to parental internalizing disorder.
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