The Onset, Course and Co‐Occurrence of Depressive and Anxiety Disorders Over a 9‐Year Period in the General Population

OBJECTIVES: Longitudinal studies that visualise individual trajectories of depressive and/or anxiety disorders can inform prevention and treatment strategies. METHODS: Participants of the Netherlands Mental Health Survey and Incidence Study (NEMESIS) were assessed at four timepoints from 2007-2009 to 2016-2018 (N = 6646 at baseline). DSM-IV disorders were assessed using the Composite International Diagnostic Interview. Onset and course trajectories were visualised with Sankey diagrams and summarised in incidence, remission, recurrence, and persistency rates, considering presence of any depressive or anxiety disorder as outcome. RESULTS: Among those without a lifetime depressive or anxiety disorder at baseline, 13% developed a depressive and/or anxiety disorder over 9 years, with higher rates in women and younger adults. Recurrence rates over 9 years were 28% for depressive, 26% for anxiety, and 38% for comorbid disorders. For those with a current disorder at baseline, recurrence (including persistence) was 33%, 31%, and 51%, respectively. Course trajectories were similar across sexes but less favourable for younger adults with a disorder history. CONCLUSIONS: Between 31% and 51% of persons with a current depressive and/or anxiety disorder do not remit over 9 years. This highlights the need for long-term treatment strategies, including ongoing monitoring, management, and relapse prevention.