The authors of this paper do not have any commercial associations that might pose a conflict of interest in connection with this manuscript.
Phenomenology of mixed states: a principal component analysis study
Version of Record online: 7 DEC 2007
Volume 9, Issue 8, pages 907–912, December 2007
How to Cite
Bertschy, G., Gervasoni, N., Favre, S., Liberek, C., Ragama-Pardos, E., Aubry, J.-M., Gex-Fabry, M. and Dayer, A. (2007), Phenomenology of mixed states: a principal component analysis study. Bipolar Disorders, 9: 907–912. doi: 10.1111/j.1399-5618.2007.00462.x
- Issue online: 7 DEC 2007
- Version of Record online: 7 DEC 2007
- Received 10 April 2006, revised and accepted for publication 31 October 2006
- bipolar disorders;
- mixed states
Objectives: To contribute to the definition of external and internal limits of mixed states and study the place of dysphoric symptoms in the psychopathology of mixed states.
Methods: One hundred and sixty-five inpatients with major mood episodes were diagnosed as presenting with either pure depression, mixed depression (depression plus at least three manic symptoms), full mixed state (full depression and full mania), mixed mania (mania plus at least three depressive symptoms) or pure mania, using an adapted version of the Mini International Neuropsychiatric Interview (DSM-IV version). They were evaluated using a 33-item inventory of depressive, manic and mixed affective signs and symptoms.
Results: Principal component analysis without rotation yielded three components that together explained 43.6% of the variance. The first component (24.3% of the variance) contrasted typical depressive symptoms with typical euphoric, manic symptoms. The second component, labeled ‘dysphoria’, (13.8%) had strong positive loadings for irritability, distressing sensitivity to light and noise, impulsivity and inner tension. The third component (5.5%) included symptoms of insomnia. Median scores for the first component significantly decreased from the pure depression group to the pure mania group. For the dysphoria component, scores were highest among patients with full mixed states and decreased towards both patients with pure depression and those with pure mania.
Conclusions: Principal component analysis revealed that dysphoria represents an important dimension of mixed states.