OBJECTIVE: Studies on the course of depression often ignore comorbid anxiety disorders or anxiety symptoms. We explored predictors of complete remission (no depression nor anxiety diagnoses at follow-up) and of the course of comorbid anxiety symptoms. We additionally tested the hypothesis that the course of anxiety disorders and symptoms in depressed patients is explained by negative life-events in the presence of high neuroticism or a low sense of mastery.
METHODS: An observational study of 270 patients (≥60 years) diagnosed with major depressive disorder and 2-year follow-up data, who participated in the Netherlands Study of Depression in Older persons (NESDO). Sociodemographic, somatic, psychiatric, and treatment variables were first explored as possible predictors. A multiple logistic regression analysis was used to examine their predictive value concerning complete remission. Subsequently, negative life-events, personality and their interaction were tested as potential predictors. Linear Mixed Models were used to assess whether the personality traits modified the effect of early and recent life-events, and time and their interactions on the course of the anxiety symptoms.
RESULTS: A total of 135 of 270 patients achieved complete remission. Depressed patients with a comorbid anxiety disorder at baseline less often achieved complete remission: 38 of 103 (37.0%) versus 97 of 167 (58.1%). The severity of depressive and anxiety symptomatology, the presence of a comorbid anxiety disorder, and a poorer physical health at baseline predicted nonremission. In line with our hypothesis, a less favorable course of self-reported anxiety symptoms was associated with more recent negative life-events, but only among patients with a high level of neuroticism or a low level of mastery.
CONCLUSION: Comorbid anxiety in depression as a negative impact on complete remission at 2-year follow-up. The course of anxiety severity seems dependent on the interaction of personality traits and life-events.