Evaluating the causal relationship between educational attainment and mental health

Abstract

We investigate the causal relationship between educational attainment (EA) and mental health using two research designs. First, we compare the relationship between EA and seventeen psychiatric diagnoses within sibship in Dutch national registry data (N = 1.7 million), controlling for unmeasured familial factors. Second, we use two-sample Mendelian Randomization, which uses genetic variants related to EA or psychiatric diagnosis as instrumental variables, to test whether there is a causal relation in either direction. Our results suggest that lower levels of EA causally increase the risk of MDD, ADHD, alcohol dependence, GAD and PTSD diagnoses. We also find evidence of a causal effect in the opposite direction for ADHD. Additionally, we find inconsistent results for schizophrenia, anorexia nervosa, OCD, and bipolar disorder, highlighting the importance of using multiple research designs to understand the complex relationship between EA and mental health.

Associations Between Polygenic Scores for Cognitive and Non-cognitive Factors of Educational Attainment and Measures of Behavior, Psychopathology, and Neuroimaging in the Adolescent Brain Cognitive Development Study

“…The cognitive PGS was also associated with decreased odds of an ADHD diagnosis and lower psychotic-like experience (PLE) severity scores, but greater risk for anorexia. This latter finding is generally in line with work showing a positive association between cognitive performance and educational attainment and anorexia (Demange et al, 2023; THE BRAINSTORM CONSORTIUM et al, 2018; Watson et al, 2019), while the correlation with lower severity of PLEs is highly consistent with other work showing PLEs to be related to decreased school performance (Davies et al, 2018; Villa et al, 2023) and general cognitive deficits (e.g., executive functioning; Sheffield et al, 2018).…”

Socioeconomic status and severe mental disorders: a bidirectional multivariable Mendelian randomisation study

“…Considering previous inconsistent evidence of a protective effect of education on mental disorders,47 we conducted supplementary post hoc MVMR analyses to assess the potential role of cognitive ability in the positive association found between genetic liability to EA and the risk of SCZ and BD. We found that the direct effect of EA on the risk of BD and SCZ, not mediated through cognitive ability, was larger than that found in the original model (MVMR-ORSCZ=3.95 per-SD-increase, p=4.55E–09; IVW-ORBIP=2.73, p=1.470E–06).…”

“…However, our study also has several limitations. First, recent studies have highlighted that MR analyses and SES phenotypes may be affected by assortative mating, dynastic effects, participation bias and design assumptions 47 68–71. There is also a limitation in the characterisation of complex phenotypes such as intelligence or income in the GWAS studies.…”

Economic determinants of county-level mental health – United States, 2019

“…College education also increases opportunities for jobs with benefits like health coverage and increased access to health-promoting knowledge and resources, resulting in lower rates of death and longer lives. 9 Lower levels of educational attainment are associated with increased risk of some psychiatric diagnoses like Major Depressive Disorder and Generalized Anxiety Disorder 33 and higher rates of suicide. 34 Conversely, poor mental health is associated with higher risk of early termination of education, limiting educational attainment.…”