The structure of negative emotional states in a postpartum inpatient sample

© 2015 Published by Elsevier B.V. Background Depression and anxiety disorders exhibit comorbidity, and the same relationships have been observed in postpartum samples. The tripartite model posits that anxiety and depression overlap due to shared and unique symptom components. The present study tested whether a one-factor model, or a three-factor model consistent with the tripartite model, provided a better fit to anxiety and depression symptoms in a postpartum sample. Methods The sample consisted of 663 postpartum psychiatric inpatients who completed self-reported questionnaires assessing symptoms of anxiety and depression. Results Confirmatory factor analysis revealed that a three-factor model consistent with the tripartite model provided a good fit to anxiety/depression data. This model consisted of three factors: positive affect, negative affect, and autonomic arousal. Positive affect was related to depressive diagnoses and negatively related to anxiety diagnoses; autonomic arousal was related to anxiety diagnoses; and negative affect was uniquely related to mixed anxiety-depressive diagnoses. Limitations The sample consisted of postpartum psychiatric inpatients and the generalisability of results to other postpartum samples is not known. Conclusions Postpartum anxiety and depression appear to be characterised by three differentiable symptom clusters. Postpartum anxiety, depression, and mixed anxiety-depressive diagnoses are differentially associated with these symptom clusters. These findings suggest that the tripartite model may be useful in guiding assessment, differentiation, and treatment of postpartum emotional disorders.