Multivariable binary regression analysis showed that age, dementia, invasive ventilation, severe shock and acute kidney injury were independent risk factors for a clinically diagnosed delirium whereas psychiatric diseases, alcohol abuse and a high SAPS2 at admission (SAPS2 ≥ 50) were not associated with a clinically diagnosed delirium (Fig 4A). This evidence concerns the gene PPP6R2 and psychiatric disorder.