title: Phenomenological subtypes of severe bipolar mixed states: a factor analytic study.
abstract: OBJECTIVE
  The correct identification of bipolar mixed states (MS) has important implications for clinical practice. The aim of the study was to define the multidimensional psychopathological structure of severe MS. To our knowledge, no factor analytical studies including only patients with MS, have been conducted before.
  
  
  METHODS
  In the first week of hospitalization, we evaluated by HAM-D-17, YMRS, BPRS and CGI, 202 Bipolar I inpatients with MS according to DSM-IV criteria referred for an ECT trial. A Principal-component analysis followed by Varimax rotation was performed on the 24-item BPRS. The relationships among different symptomatological subtypes and other clinical characteristics were explored.
  
  
  RESULTS
  Six interpretable factors were extracted: Psychotic-positive symptoms, Mania, Disorientation-Unusual Motor Behaviour, Depression, Negative Symptoms and Anxiety. On the basis of the highest z-scores, we found 6 "dominant" BPRS factor groups, that were statistically distinct and without significant overlap in the main symptomatological presentation. Only 29 (14.4%) of our patients could be described as "Dominant Manic" and 48 (23.8%) as "Dominant Depressive"; most importantly 125 (61.9%) were neither predominately-manic nor predominately-depressive. Variables including age, number of previous episodes, suicidal behavior and HAM-D and YMRS scores significantly differentiated the subtypes.
  
  
  CONCLUSIONS
  At least in the most severe forms, MS appears to represent more than the superposition of affective symptoms of opposite polarity. Anxiety, perplexity, psychotic experiences, motor disturbances and grossly disorganized behavior seem to arise from protracted intra-episodic instability and presence of a drive state influencing the mood state and the emotional resonance.
authors.affiliation: Clinica Psichiatrica, Dipartmento di Medicina Sperimentale, University of Pisa, Pisa, Italy. Electronic address: gperugi@med.unipi.it.
authors.forename: Giulio
authors.initials: G
authors.lastname: Perugi
authors.affiliation: Clinica Psichiatrica, Dipartmento di Medicina Sperimentale, University of Pisa, Pisa, Italy.
authors.forename: Pierpaolo
authors.initials: P
authors.lastname: Medda
authors.affiliation: Department of Psychiatry, The University of Texas Health Science Center, Houston, TX, USA.
authors.forename: Alan C
authors.initials: AC
authors.lastname: Swann
authors.affiliation: Serviço de Psiquiatria e Saúde Mental, Hospital de Santa Maria - CHLN, Lisboa, Portugal - Faculdade de Medicina de Lisboa, Universidade de Lisboa.
authors.forename: Joao
authors.initials: J
authors.lastname: Reis
authors.affiliation: Clinica Psichiatrica, Dipartmento di Medicina Sperimentale, University of Pisa, Pisa, Italy.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Rizzato
authors.affiliation: Clinica Psichiatrica, Dipartmento di Medicina Sperimentale, University of Pisa, Pisa, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Mauri
mesh_terms: D000339:Affect; D000342:Affective Symptoms; D001007:Anxiety; D001714:Bipolar Disorder / Q000145:classification* / Q000175:diagnosis / Q000523:psychology*; D003221:Confusion / Q000523:psychology; D003863:Depression; D004644:Emotions; D005163:Factor Analysis, Statistical; D006801:Humans; D007297:Inpatients; D011618:Psychotic Disorders / Q000175:diagnosis / Q000523:psychology; D059020:Suicidal Ideation; D013406:Suicide, Attempted / Q000523:psychology