The number of cases with an additional psychiatric diagnosis (bipolar disorder, schizophrenia, anxiety, autism, ADHD, SUD) are shown in Extended Data Figure 2. When comparing these frequencies with published estimates of lifetime prevalence three main factors are important to keep in mind: (i) The investigated Danish iPSYCH cohort is young (individuals born between 1981-2008; mean age 23.37 years at follow-up), (ii) phenotypes are based on register-based hospital-diagnoses and (iii) people with early onset of affective disorders have a greater absolute risk of developing schizophrenia and related disorders, compared to those with later onsets9. Life-time risk of hospital-diagnosed schizophrenia and depression (ICD10 F32-F33) in the Danish population has been estimated to 1.75% (average of 1.93% in males and 1.56% in females) and 12.3% (average of 9.07% in males and 15.5% in females), respectively3. Extended Data Figure 2 shows that the frequencies of schizophrenia and depression in the young, randomly selected iPSYCH-population-sample are 1% and 2.7%, respectively, based on register-based hospital diagnosis. Schizophrenia has relatively early onset, while depression has relatively late onset, hence the relatively low observed 2.7% frequency of depression
