title: Effects of amphetamine on reactivity to emotional stimuli.
abstract: BACKGROUND
  Most studies of the reinforcing effects of stimulants have focused on the drugs' capacity to induce positive mood (i.e., euphoria). However, recent findings suggest drugs may also alter emotional reactivity to external stimuli, and that this may occur independently of direct effects on mood.
  
  
  OBJECTIVE
  We aimed to examine effects of D: -amphetamine, a prototypic stimulant, on self-reported and psychophysiological reactivity to emotional stimuli as well as overall subjective mood. We predicted that amphetamine would enhance reactivity to pleasant stimuli, particularly, stimuli with social content and that these effects would be independent of the drug's direct effects on mood.
  
  
  METHODS
  Over three sessions, 36 healthy normal adults received placebo, D: -amphetamine 10 and 20 mg under counterbalanced double-blind conditions. At each session, emotional reactivity to standardized positive, neutral, and negative pictures with and without social content was measured in self-reports and facial muscles sensitive to emotional state. Drug effects on cardiovascular variables and subjective mood were also measured.
  
  
  RESULTS
  Amphetamine produced euphoria, feelings of drug effect, and increased blood pressure. Most notably, amphetamine enhanced self-reported positive reactions to all pictures and psychophysiological reactions to positive pictures. These effects were not significantly related to drug-induced mood changes. Contrary to our hypothesis, effects of amphetamine on emotional reactivity were not moderated by social content.
  
  
  CONCLUSIONS
  This study demonstrates a previously unexamined and potentially reinforcing effect of stimulant drugs in humans, distinct from more typically measured euphorigenic effects, and suggests new areas of research in stimulant abuse risk and adaptations occurring during drug dependence.
authors.affiliation: Department of Psychiatry and Behavioral Neuroscience, MC 3077, University of Chicago, 5841 S. Maryland Ave., Chicago, IL, USA.
authors.forename: Margaret C
authors.initials: MC
authors.lastname: Wardle
authors.forename: Harriet
authors.initials: H
authors.lastname: de Wit
mesh_terms: D000328:Adult; D000339:Affect / Q000187:drug effects*; D001794:Blood Pressure / Q000187:drug effects; D000697:Central Nervous System Stimulants / Q000008:administration & dosage / Q000494:pharmacology*; D003913:Dextroamphetamine / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004644:Emotions; D005059:Euphoria / Q000187:drug effects*; D005152:Facial Muscles / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D055815:Young Adult
chemical_list: D000697:Central Nervous System Stimulants; D003913:Dextroamphetamine