title: [Comparative regions of interest study in schizophrenia, panic disorder and its comorbidity: the relationship between hippocampal volume and positive psychotic symptoms].
abstract: BACKGROUND
  Schizophrenia and panic disorder have been associated with limbic alterations, such as reduced volumes of the hippocampus and amygdala. However, there are conflicting results and a lack of previous neuroimaging studies assessing the implication of these structures when the two diagnosis are comorbid. AIM. To determine the type and magnitude of volumetric limbic alterations in schizophrenia, panic disorder and their comorbidity.
  
  
  METHODS
  We measured the volume of the amygdala and hippocampus using a manual regions of interest segmentation method in schizophrenic patients (group 1), panic disorder (group 2), those who present comorbidity of the two diagnosis (group 3), and a control group of healthy subjects (group 4).
  
  
  RESULTS
  Patients included in groups 1 and 3 have significantly lower volume of left hippocampus than control group. In these groups, we did find that the volume of the left hippocampus was positively associated with positive symptoms' severity. We did not find volumetric differences in the amygdala between the groups.
  
  
  CONCLUSIONS
  Our results confirm a decreased volume of the left hippocampus in schizophrenia. The association between the severity of positive psychotic symptoms (delusions and hallucinations) and hippocampus volume could be mediated by the propensity to develop a fear conditioned response to neutral stimuli in subjects with higher hippocampal volumes.
authors.affiliation: Instituto de Neuropsiquiatria y Adicciones (INAD), Barcelona, Espana.
authors.forename: Romina
authors.initials: R
authors.lastname: Cortizo-Vidal
authors.forename: Susana
authors.initials: S
authors.lastname: Carmona-Canabate
authors.forename: Marisol
authors.initials: M
authors.lastname: Picado-Rossi
authors.forename: Guillem
authors.initials: G
authors.lastname: Pailhez-Vindual
authors.forename: Óscar
authors.initials: Ó
authors.lastname: Vilarroya-Oliver
authors.forename: Antoni
authors.initials: A
authors.lastname: Bulbena-Vilarasa
mesh_terms: D000328:Adult; D000679:Amygdala / Q000473:pathology; D001007:Anxiety / Q000473:pathology; D015897:Comorbidity; D005260:Female; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D007406:Interview, Psychological; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D059906:Neuroimaging; D015588:Observer Variation; D009929:Organ Size; D016584:Panic Disorder / Q000150:complications / Q000453:epidemiology / Q000473:pathology* / Q000523:psychology; D012559:Schizophrenia / Q000150:complications / Q000453:epidemiology / Q000473:pathology*; D012565:Schizophrenic Psychology; D012720:Severity of Illness Index; D063189:Symptom Assessment