title: Influence of the noradrenergic system on the formation of intrusive memories in women: an experimental approach with a trauma film paradigm.
abstract: Intrusive memories of traumatic events are a core feature of post-traumatic stress disorder but little is known about the neurobiological formation of intrusions. The aim of this study was to determine whether the activity of the noradrenergic system during an intrusion-inducing stressor would influence subsequent intrusive memories.
  
  
  
  We conducted an experimental, double-blind, placebo-controlled study in 118 healthy women. Participants received a single dose of either 10 mg yohimbine, stimulating noradrenergic activity, or 0.15 mg clonidine, inhibiting noradrenergic activity, or placebo. Subsequently, they watched an established trauma film which induced intrusions. The number of consecutive intrusions resulting from the trauma film, the vividness of the intrusions, and the degree of distress evoked by the intrusions were assessed during the following 4 days. Salivary cortisol and α-amylase were collected before and after the trauma film.
  
  
  
  A significant time × treatment interaction for the number of intrusions and the vividness of intrusions indicated a different time course of intrusions depending on treatment. Post-hoc tests revealed a delayed decrease of intrusions and a delayed decrease of intrusion vividness after the trauma film in the yohimbine group compared with the clonidine and placebo groups. Furthermore, after yohimbine administration, a significant increase in salivary cortisol levels was observed during the trauma film.
  
  
  
  Our findings indicate that pharmacological activation of the noradrenergic system during an emotionally negative event makes an impact on consecutive intrusive memories and their vividness in healthy women. The noradrenergic system seems to be involved in the formation of intrusive memories.
authors.affiliation: Department of Psychiatry and Psychotherapy,Charité - Universitätsmedizin Berlin,Campus Benjamin Franklin,Berlin,Germany.
authors.forename: F
authors.initials: F
authors.lastname: Rombold
authors.affiliation: Department of Psychiatry and Psychotherapy,Charité - Universitätsmedizin Berlin,Campus Benjamin Franklin,Berlin,Germany.
authors.forename: K
authors.initials: K
authors.lastname: Wingenfeld
authors.affiliation: Department of Psychology,Freie Universitaet Berlin,Berlin,Germany.
authors.forename: B
authors.initials: B
authors.lastname: Renneberg
authors.affiliation: Department of Psychiatry and Psychotherapy,Charité - Universitätsmedizin Berlin,Campus Benjamin Franklin,Berlin,Germany.
authors.forename: J
authors.initials: J
authors.lastname: Hellmann-Regen
authors.affiliation: Department of Psychiatry and Psychotherapy,Charité - Universitätsmedizin Berlin,Campus Benjamin Franklin,Berlin,Germany.
authors.forename: C
authors.initials: C
authors.lastname: Otte
authors.affiliation: Department of Psychiatry and Psychotherapy,Charité - Universitätsmedizin Berlin,Campus Benjamin Franklin,Berlin,Germany.
authors.forename: S
authors.initials: S
authors.lastname: Roepke
mesh_terms: D000293:Adolescent; D018663:Adrenergic Agents / Q000008:administration & dosage / Q000494:pharmacology*; D058647:Adrenergic alpha-2 Receptor Agonists / Q000008:administration & dosage / Q000494:pharmacology; D058669:Adrenergic alpha-2 Receptor Antagonists / Q000008:administration & dosage / Q000494:pharmacology; D000328:Adult; D003000:Clonidine / Q000008:administration & dosage / Q000494:pharmacology; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism*; D061212:Memory, Episodic; D009638:Norepinephrine / Q000378:metabolism / Q000502:physiology*; D000067073:Psychological Trauma / Q000378:metabolism* / Q000503:physiopathology*; D015016:Yohimbine / Q000008:administration & dosage / Q000494:pharmacology; D055815:Young Adult
chemical_list: D018663:Adrenergic Agents; D058647:Adrenergic alpha-2 Receptor Agonists; D058669:Adrenergic alpha-2 Receptor Antagonists; D015016:Yohimbine; D003000:Clonidine; D006854:Hydrocortisone; D009638:Norepinephrine
keywords: Clonidine; intrusions; post-traumatic stress disorder; trauma film paradigm; yohimbine