title: Phenomenology of mixed states: a principal component analysis study.
abstract: OBJECTIVE
  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.
authors: Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Geneva, Switzerland. gilles.bertschy@hcuge.ch
authors: G
authors: G
authors: Bertschy
authors: N
authors: N
authors: Gervasoni
authors: S
authors: S
authors: Favre
authors: C
authors: C
authors: Liberek
authors: E
authors: E
authors: Ragama-Pardos
authors: J-M
authors: JM
authors: Aubry
authors: M
authors: M
authors: Gex-Fabry
authors: A
authors: A
authors: Dayer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D025341:Principal Component Analysis; D011569:Psychiatric Status Rating Scales; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013312:Stress, Physiological / Q000145:classification* / Q000175:diagnosis* / Q000453:epidemiology* / Q000503:physiopathology