Objective: To investigate the effect of childhood life events and childhood trauma on the onset and recurrence of depressive and/or anxiety disorders over a 2-year period in participants without current psychopathology at baseline. Method: Longitudinal data in a large sample of participants without baseline DSM-IV depressive or anxiety disorders (n = 1,167, aged 18 to 65 years; assessed between 2004-2007) were collected in the Netherlands Study of Depression and Anxiety (NESDA). Childhood life events and childhood trauma were assessed at baseline with a semistructured interview. The Composite International Diagnostic Interview, based on DSM-IV criteria, was used to diagnose first onset or recurrent depressive and/or anxiety disorders over a 2-year period. Results: At baseline, 172 participants (14.7%) reported at least 1 childhood life event, and 412 (35.3%) reported any childhood trauma. During 2 years of follow-up, 226 participants (19.4%) developed a new (n = 58) or recurrent (n = 168) episode of a depressive and/or anxiety disorder. Childhood life events did not predict the onset and recurrence of depressive or anxiety disorders. Emotional neglect and psychological, physical, and sexual abuse were all associated with an increased risk of first onset and recurrence of either depressive or comorbid disorders (P <.001), but not of anxiety disorders. In multivariate models, emotional neglect was the only significant independent predictor of first onset and recurrence of any depressive or comorbid disorder (P =.002). These effects were primarily mediated by the severity of (subclinical) depressive symptoms at baseline and, to a lesser extent, by a prior lifetime diagnosis of a depressive and/or anxiety disorder. Conclusions: Childhood maltreatment is a key environmental risk factor, inducing vulnerability to develop new and recurrent depressive and comorbid anxiety and depressive episodes.