Investigating interactions between early life stress and two single nucleotide polymorphisms in HSD11B2 on the risk of schizophrenia

•A two-stage design was applied in the study, with:.•A nationwide, population-based cohort study investigating the effects of early life stress on the risk of developing schizophrenia. We found a significantly increased risk of schizophrenia after exposure to stress within the first 2 years of life. No increased risk of schizophrenia was found after stress exposure during pregnancy.•A nested case-control study with information on genotype from a cortisol-regulating gene (HSD11B2). We investigated the risk of schizophrenia after early life stress according to genotypes, and found that individuals hetero- or homozygous for the minor A allele of the exonic SNP rs5479 had a significantly increased risk after exposure in the period 3–9 years after birth. This risk was significantly higher than for individuals homozygous for the major C allele of rs5479.•No interaction was found between any of the SNPs and exposure during pregnancy.