Direct effects of diazepam on emotional processing in healthy volunteers.
BACKGROUND
Pharmacological agents used in the treatment of anxiety have been reported to decrease threat relevant processing in patients and healthy controls, suggesting a potentially relevant mechanism of action. However, the effects of the anxiolytic diazepam have typically been examined at sedative doses, which do not allow the direct actions on emotional processing to be fully separated from global effects of the drug on cognition and alertness.


OBJECTIVE
The aim of this study was to investigate the effect of a lower, but still clinically effective, dose of diazepam on emotional processing in healthy volunteers.


METHODS
Twenty-four participants were randomised to receive a single dose of diazepam (5 mg) or placebo. Sixty minutes later, participants completed a battery of psychological tests, including measures of non-emotional cognitive performance (reaction time and sustained attention) and emotional processing (affective modulation of the startle reflex, attentional dot probe, facial expression recognition, and emotional memory). Mood and subjective experience were also measured.


RESULTS
Diazepam significantly modulated attentional vigilance to masked emotional faces and significantly decreased overall startle reactivity. Diazepam did not significantly affect mood, alertness, response times, facial expression recognition, or sustained attention.


CONCLUSIONS
At non-sedating doses, diazepam produces effects on attentional vigilance and startle responsivity that are consistent with its anxiolytic action. This may be an underlying mechanism through which benzodiazepines exert their therapeutic effects in clinical anxiety.
Murphy
S E
SE
University Department of Psychiatry, Warneford Hospital, Warneford Lane, Oxford,UK.
Downham
C
C
Cowen
P J
PJ
Harmer
C J
CJ
D000328:Adult; D001288:Attention / Q000187:drug effects; D003975:Diazepam / Q000009:adverse effects / Q000494:pharmacology*; D004311:Double-Blind Method; D004576:Electromyography; D005149:Facial Expression; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000009:adverse effects / Q000494:pharmacology*; D008297:Male; D008568:Memory / Q000187:drug effects; D011939:Mental Recall / Q000187:drug effects; D010465:Perception / Q000187:drug effects*; D011597:Psychomotor Performance / Q000187:drug effects; D011930:Reaction Time / Q000187:drug effects; D021641:Recognition, Psychology / Q000187:drug effects; D012701:Serotonin / Q000502:physiology; D012938:Social Perception; D055815:Young Adult
D006993:Hypnotics and Sedatives; D012701:Serotonin; D003975:Diazepam