Table 1.
Single-variable and multivariable inverse-variance weighted mendelian randomization associations between educational attainment and cognitive performance on risk of suicide attempt in individuals with and without mental disorders.
| Outcome | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Suicide attempt: model 1 | Suicide attempt: model 2 | |||||||||
| Exposures | N SNPS | OR | OR LCI | OR UCI | P-value | N SNPS | OR | OR LCI | OR UCI | P-value |
| SVMR | ||||||||||
| Educational attainment | 223 | 0.524 | 0.412 | 0.666 | 1.07E−07 | 224 | 0.687 | 0.540 | 0.874 | 2.20E−03 |
| Cognitive performance | 104 | 0.714 | 0.577 | 0.885 | 2.02E−03 | 104 | 0.794 | 0.636 | 0.990 | 4.01E−02 |
| Household income | 41 | 0.591 | 0.389 | 0.901 | 1.41E−02 | 41 | 0.721 | 0.480 | 1.081 | 1.13E−01 |
| MVMR | ||||||||||
| Educational attainment | 288 | 0.450 | 0.314 | 0.644 | 1.00E−04 | 288 | 0.556 | 0.388 | 0.796 | 2.00E−03 |
| Cognitive performance | 288 | 1.044 | 0.764 | 1.426 | 7.86E−01 | 288 | 1.081 | 0.789 | 1.482 | 6.29E−01 |
| MVMR: adjusting for Income | ||||||||||
| Educational attainment | 282 | 0.342 | 0.206 | 0.568 | 1.61E−04 | 283 | 0.437 | 0.258 | 0.739 | 2.00E−03 |
| Cognitive performance | 282 | 1.182 | 0.842 | 1.659 | 3.33E−01 | 283 | 1.143 | 0.803 | 1.627 | 4.57E−01 |
| Household income | 282 | 1.101 | 0.627 | 1.932 | 7.38E−01 | 283 | 1.225 | 0.683 | 2.197 | 4.96E−01 |
Results are presented as odds ratios (OR) with 95% confidence intervals for the effect of a unit standard deviation increase in educational attainment (years of schooling: mean = 15.1, s.d.=4.2 years), a unit standard deviation increase in standardized cognitive performance score (mean 0.00, s.d. = 0.99–1.00), and categorical increase in average annual household income before tax, on the risk of suicide attempt (hospital recorded non-fatal suicide attempt, including secondary diagnoses of poisoning by drugs or other substances, or injuries to the hand, wrist, and forearm). Model 1 was based upon iPSYCH Suicide Attempt Risk GWAS not accounting for comorbid mental disorders (N = 50,260); model 2 was based upon iPSYCH Suicide Attempt Risk GWAS accounting for diagnosed comorbid mental disorders in the same cohort sample (N = 50,260): schizophrenia, bipolar disorder, affective disorders, autism spectrum disorder, anorexia, and “any other disorder”. (1) SVMR results show effects of exposures on outcomes analyzed separately: the estimates are considered to be the total effect (direct plus indirect effect) of the exposure on the outcome; (2) MVMR results show effects of EA and CP analyzed simultaneously: the estimates are interpreted as the direct effect of the exposure on the outcome, independent of the effect of the other exposure; (3) MVMR adjusting for Average Household Income (Before Tax) showing effects of EA, CP and AHI analyzed simultaneously. All results shown are pruned of variants identified as outliers by the MR-PRESSO test (MR-PRESSO P < 0.10). Cochran Q tests did not indicate heterogeneity and MR Egger intercept test did not indicate pleiotropy for any model. See Supplementary Tables 10–12 for full results.
SVMR single-variable Mendelian randomization, MVMR multivariable Mendelian randomization, N number, SNPs single-nucleotide polymorphisms, OR odds ratio, OR LCI 95% confidence interval lower bound, OR UCI 95% confidence interval upper bound.