neuroticism, anxiety, and depressive symptoms (28) (mean 0, std 0.7); controls were required never to have scored highly (≥0.65) on this factor score. Finally, controls and their parents were required to have been born in the Netherlands or western Europe. Only one control per family was selected. There were N=1,703 controls from the NTR and additional controls from NESDA (N=133 from general practice, N=24 from ARIADNE). NESDA controls had no lifetime diagnosis of MDD or an anxiety disorder as assessed by the CIDI and reported low depressive symptoms at baseline (K-10 score <16 and Inventory of Depressive Symptoms score <4) (29, 30).
