The Internalising and Externalising Dimensions of Affective Symptoms in Depressed (Unipolar) and Bipolar Patients

Objective: To analyse the internalising and externalising dimensions of affective states in depressed (unipolar) and bipolar patients approximately 2 years after discharge from psychiatric hospitals in Denmark. Method: The 42-item symptom scale based on the Beck Depression Inventory was used for the measurement of both the internalising dimension of affective symptoms (depression including suicidal ideas, anxiety and asthenia) and the externalising dimension (mania). To supplement the latter dimension, the WHO-5 questionnaire was included. These questionnaires were mailed to a large population of patients with depressive (unipolar) or bipolar disorders, representative of patients treated in hospital settings in Denmark, approximately 2 years after discharge from hospital. Results: In total, 244 unipolars and 214 bipolars were included in the study. Mokken analysis showed that depressive (unipolar) patients could be measured more validly than bipolar patients on the internalising subscales of depression, anxiety and asthenia. On the externalising dimension of psychological well-being (WHO-5), both groups of patients could be validly measured. Approximately 2 years after discharge from hospital, around 36% of the unipolars and 19% of the bipolars had a moderate to severe depression. In a control group of healthy subjects, 4% had a moderate to severe depression. Less than 5% even in the bipolar group of patients were hypomanic. Conclusion: Approximately 2 years after discharge from psychiatric hospitals in Denmark, depressive (unipolar) patients scored significantly higher than bipolar patients on the internalising dimension and suicidal ideas, and significantly lower on the externalising dimension of psychological well-being.