title: Phenomenology of first-episode psychosis in schizophrenia, bipolar disorder, and unipolar depression: a comparative analysis.
abstract: OBJECTIVE
  This study sought to identify similarities and differences in symptom characteristics at initial presentation of first psychotic episodes in schizophrenia, bipolar disorder and unipolar depression.
  
  
  METHODS
  The Structured Interview for DSM-IV (SCID) and Positive and Negative Syndrome Scale (PANSS) were administered to consecutive admission study-eligible patients (n=101) presenting for treatment during their first acute phase of psychotic illness. Forty-nine percent of patients met diagnostic criteria for schizophrenia, 29% for psychotic bipolar disorder and 22% for unipolar depression with psychosis. The PANSS was analyzed using five-factor scoring that included Positive, Negative, Cognitive, Excitement, and Depression factors, and composite cluster scores that assessed Anergia, Thought Disturbance, and Paranoia.
  
  
  RESULTS
  Schizophrenia and bipolar disorder patients demonstrated significantly more Positive symptoms, Thought Disturbance and Paranoia than unipolar depressed patients. Schizophrenia and unipolar depressed patients demonstrated significantly more Negative symptoms and Anergia than bipolar patients. Patients with schizophrenia reported more severe Cognitive Disorganization than patients with either bipolar disorder or uni-polar depression (p<.05).
  
  
  CONCLUSIONS
  Findings from this study demonstrate an informative pattern of similarities and differences in the phenomenology of psychotic disorders at first illness presentation. Commonalities in symptom profiles reflect considerable symptom overlap among psychotic disorders and, thus, the importance of multidimensional differential diagnosis for these conditions. The differences across disorders in Positive and Negative symptom severity, Thought Disorder, Paranoia, and Anergia, and especially the higher level of Cognitive Disorganization seen in schizophrenia patients, point to clinically informative differences across these disorders that are relevant to clinical diagnostic practice and models of psychopathology.
authors.affiliation: Center for Cognitive Medicine, University of Illinois, Chicago, USA.
authors.forename: Cherise
authors.initials: C
authors.lastname: Rosen
authors.forename: Robert
authors.initials: R
authors.lastname: Marvin
authors.forename: James L
authors.initials: JL
authors.lastname: Reilly
authors.forename: Ovidio
authors.initials: O
authors.lastname: Deleon
authors.forename: Margret S H
authors.initials: MS
authors.lastname: Harris
authors.forename: Sarah K
authors.initials: SK
authors.lastname: Keedy
authors.forename: Hugo
authors.initials: H
authors.lastname: Solari
authors.forename: Peter
authors.initials: P
authors.lastname: Weiden
authors.forename: John A
authors.initials: JA
authors.lastname: Sweeney
mesh_terms: D000293:Adolescent; D000328:Adult; D001714:Bipolar Disorder / Q000175:diagnosis* / Q000523:psychology; D003866:Depressive Disorder / Q000175:diagnosis* / Q000523:psychology; D003937:Diagnosis, Differential; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000175:diagnosis*; D012559:Schizophrenia / Q000175:diagnosis*; D012565:Schizophrenic Psychology; D055815:Young Adult