title: Neuroimaging in specific phobia disorder: a systematic review of the literature.
abstract: OBJECTIVE
  Specific phobia (SP) is characterized by irrational fear associated with avoidance of specific stimuli. In recent years, neuroimaging techniques have been used in an attempt to better understand the neurobiology of anxiety disorders. The objective of this study was to perform a systematic review of articles that used neuroimaging techniques to study SP.
  
  
  METHODS
  A literature search was conducted through electronic databases, using the keywords: imaging, neuroimaging, PET, spectroscopy, functional magnetic resonance, structural magnetic resonance, SPECT, MRI, DTI, and tractography, combined with simple phobia and specific phobia. One-hundred fifteen articles were found, of which 38 were selected for the present review. From these, 24 used fMRI, 11 used PET, 1 used SPECT, 2 used structural MRI, and none used spectroscopy.
  
  
  RESULTS
  The search showed that studies in this area were published recently and that the neuroanatomic substrate of SP has not yet been consolidated.
  
  
  CONCLUSIONS
  In spite of methodological differences among studies, results converge to a greater activation in the insula, anterior cingulate cortex, amygdala, and prefrontal and orbitofrontal cortex of patients exposed to phobia-related situations compared to controls. These findings support the hypotheses of the hyperactivation of a neuroanatomic structural network involved in SP.
authors.affiliation: Department of Neuroscience and Behavior, Ribeirão Preto Medical School, Universidade de São Paulo, São Paulo, Brazil. ilalinares@yahoo.com.br
authors.forename: Ila M P
authors.initials: IM
authors.lastname: Linares
authors.forename: Clarissa
authors.initials: C
authors.lastname: Trzesniak
authors.forename: Marcos Hortes N
authors.initials: MH
authors.lastname: Chagas
authors.forename: Jaime E C
authors.initials: JE
authors.lastname: Hallak
authors.forename: Antonio E
authors.initials: AE
authors.lastname: Nardi
authors.forename: José Alexandre S
authors.initials: JA
authors.lastname: Crippa
mesh_terms: D000679:Amygdala / Q000503:physiopathology*; D001931:Brain Mapping / Q000379:methods*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D015201:Meta-Analysis as Topic; D010698:Phobic Disorders / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy; D014055:Tomography, Emission-Computed / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods