title: Formal thought disorder in non-clinical individuals with auditory verbal hallucinations.
abstract: BACKGROUND
  Auditory verbal hallucinations (AVH) and formal thought disorder (FTD) may originate from the same aberration in the language system. The hypothesis of a shared neurobiological basis would be strengthened by the presence of FTD in individuals who frequently experience AVH, but do not meet DSM-IV criteria for a psychotic disorder.
  
  
  METHODS
  In this study, FTD was quantified in 40 non-clinical subjects with AVH, in 50 healthy subjects without AVH and in 40 schizophrenia patients with AVH. Recorded speech samples were analysed by one rater who was blind to the presence/absence of AVH and to diagnosis, using the Thought and Language Index.
  
  
  RESULTS
  Negative FTD was barely present in non-clinical subjects with AVH and in healthy controls without AVH. Positive FTD, however, was significantly higher in both groups experiencing AVH than in controls without AVH. Severity of positive FTD did not differ significantly between non-clinical subjects with AVH and schizophrenia patients with AVH.
  
  
  CONCLUSIONS
  Negative FTD (alogia) appears not to be associated with AVH. However, the fact that positive FTD (disorganised speech) in schizophrenia patients with AVH is equally high in non-clinical subjects with AVH indicates that these two symptoms tend to co-occur, which may be suggestive of a shared neurobiological substrate.
authors.affiliation: The Neuroscience Division University Medical Center Utrecht, Rudolf Magnus School for Neuroscience, Netherlands. I.Sommer@umcutrecht.nl
authors.forename: Iris E
authors.initials: IE
authors.lastname: Sommer
authors.forename: Annelea M C
authors.initials: AM
authors.lastname: Derwort
authors.forename: Kirstin
authors.initials: K
authors.lastname: Daalman
authors.forename: Antoin D
authors.initials: AD
authors.lastname: de Weijer
authors.forename: Peter F
authors.initials: PF
authors.lastname: Liddle
authors.forename: Marco P M
authors.initials: MP
authors.lastname: Boks
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D005260:Female; D006212:Hallucinations / Q000150:complications*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000150:complications*; D012565:Schizophrenic Psychology; D013064:Speech Disorders / Q000209:etiology*; D011795:Surveys and Questionnaires; D014705:Verbal Behavior