title: Diurnal variation in cue-induced responses among protracted abstinent heroin users.
abstract: OBJECTIVE
  The physiological and psychological responses to drug cue exposure have been assessed in substance abusers. However, there is no study to demonstrate whether the responses to drug cue exposure are diurnal dependence. The present study was to examine whether there was a variation in drug-related cue reactivity across the diurnal cycle among recently abstinent opiate addicts.
  
  
  METHODS
  Four groups of 20 abstinent heroin dependent patients (n=80) were exposed to both neutral and drug-related videos at four separate times during the day: 8:00, 12:00, 16:00, and 20:00 h. Physiological and psychological responses, including heart rate, blood pressure, heroin craving, and subjective anxiety were assessed before and after each cue exposure.
  
  
  RESULTS
  Drug cue significantly increased craving ratings compared to neutral cues across all the four separate times of day. Drug cue-induced craving was greater in the morning (8:00 am) than noon (12:00 pm), but was similar to evening assessments (8 pm). Drug cues also significantly increased anxiety, which positively correlated with cue-induced craving. Drug cues increased heart rate, systolic and diastolic blood pressures, which were not correlated with cue-induced craving or anxiety. However, no time effects were found on the three physiological measures.
  
  
  CONCLUSIONS
  Cue-induced craving could be profoundly affected by the time points of cue exposure, using cue-reactivity paradigm. The relative sensitivity of morning and evening assessments of drug craving suggests a need for replication and further research on mechanisms contributing to these diurnal variations.
authors.affiliation: National Institute on Drug Dependence, Peking University, Beijing 100083, China.
authors.forename: Zhen-Yu
authors.initials: ZY
authors.lastname: Ren
authors.forename: Xiao-Li
authors.initials: XL
authors.lastname: Zhang
authors.forename: Yu
authors.initials: Y
authors.lastname: Liu
authors.forename: Li-Yan
authors.initials: LY
authors.lastname: Zhao
authors.forename: Jie
authors.initials: J
authors.lastname: Shi
authors.forename: Yanping
authors.initials: Y
authors.lastname: Bao
authors.forename: Xiang Yang
authors.initials: XY
authors.lastname: Zhang
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Kosten
authors.forename: Lin
authors.initials: L
authors.lastname: Lu
mesh_terms: D000328:Adult; D001007:Anxiety / Q000523:psychology; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D002940:Circadian Rhythm / Q000502:physiology*; D003463:Cues; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006556:Heroin Dependence / Q000523:psychology*; D006801:Humans; D008297:Male; D011569:Psychiatric Status Rating Scales; D013375:Substance Withdrawal Syndrome / Q000523:psychology; D055815:Young Adult