title: A polymorphism in the gene of the endocannabinoid-degrading enzyme FAAH (FAAH C385A) is associated with emotional-motivational reactivity.
abstract: BACKGROUND
  The endocannabinoid (eCB) system is implicated in several psychiatric disorders. Investigating emotional-motivational dysfunctions as underlying mechanisms, a study in humans revealed that in the C385A polymorphism of the fatty acid amide hydrolase (FAAH), the degrading enzyme of the eCB anandamide (AEA), A carriers, who are characterized by increased signaling of AEA as compared to C/C carriers, exhibited reduced brain reactivity towards unpleasant faces and enhanced reactivity towards reward. However, the association of eCB system with emotional-motivational reactivity is complex and bidirectional due to upcoming compensatory processes.
  
  
  OBJECTIVE
  Therefore, we further investigated the relationship of the FAAH polymorphism and emotional-motivational reactivity in humans.
  
  
  METHODS
  We assessed the affect-modulated startle, and ratings of valence and arousal in response to higher arousing pleasant, neutral, and unpleasant pictures in 67 FAAH C385A                   C/C carriers and 45 A carriers.
  
  
  RESULTS
  Contrarily to the previous functional MRI study, A carriers compared to C/C carriers exhibited an increased startle potentiation and therefore emotional responsiveness towards unpleasant picture stimuli and reduced startle inhibition indicating reduced emotional reactivity in response to pleasant pictures, while both groups did not differ in ratings of arousal and valence.
  
  
  CONCLUSIONS
  Our findings emphasize the bidirectionality and thorough examination of the eCB system's impact on emotional reactivity as a central endophenotype underlying various psychiatric disorders.
authors: Department of Psychology-Biological Psychology, Clinical Psychology, and Psychotherapy, University of Würzburg, Marcusstr 9-11, 97070 Wurzburg, Germany.
authors: Annette
authors: A
authors: Conzelmann
authors: Andreas
authors: A
authors: Reif
authors: Christian
authors: C
authors: Jacob
authors: Peter
authors: P
authors: Weyers
authors: Klaus-Peter
authors: KP
authors: Lesch
authors: Beat
authors: B
authors: Lutz
authors: Paul
authors: P
authors: Pauli
mesh_terms: D000328:Adult; D000581:Amidohydrolases / Q000235:genetics*; D001143:Arousal / Q000502:physiology*; D004644:Emotions / Q000502:physiology*; D063388:Endocannabinoids / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D009042:Motivation / Q000502:physiology; D011110:Polymorphism, Genetic; D013216:Reflex, Startle / Q000502:physiology*; D055815:Young Adult; D000099252:Fatty Acid Amide Hydrolases
chemical_list: D000581:Amidohydrolases; D063388:Endocannabinoids; D000099252:Fatty Acid Amide Hydrolases