title: Acoustic startle reduction in cocaine dependence persists for 1 year of abstinence.
abstract: BACKGROUND
  Chronic cocaine use results in long-lasting neurochemical changes that persist beyond the acute withdrawal period. Previous work from our group reported a profound reduction in the acoustic startle response (ASR) in chronic cocaine-dependent subjects in early abstinence compared to healthy controls that may be related to long-lasting neuroadaptations following withdrawal from chronic cocaine use.
  
  
  OBJECTIVE
  This study aims to investigate the persistence and time course of the decrements in the ASR of cocaine-dependent subjects during prolonged abstinence.
  
  
  METHODS
  Seventy-six cocaine-dependent (COC) subjects and 30 controls (CONT) were tested, the former after a period of heavy cocaine dependence. COC subjects were retested sequentially for 1 year of abstinence or until relapse. ASR testing was conducted at 3-dB levels and the eye-blink component of the startle response was quantified with electromyographic recording of the orbicularis oculi muscle.
  
  
  RESULTS
  While there was no difference in startle magnitude between CONT and COC in early abstinence, by day 40 of abstinence COC subjects exhibited a statistically significant decline (p = 0.0057) in ASR magnitude as compared with CONT and this decrement persisted for up to 1 year of abstinence (p = 0.0165). In addition, startle latency was slower in COC subjects as compared with CONT at all stages of abstinence.
  
  
  CONCLUSIONS
  These results replicate and expand upon the earlier finding that chronic cocaine use impairs the ASR in a manner that persists beyond the acute withdrawal period. This phenomenon may represent a biological measure of long-term neural changes accompanying cocaine dependence and subsequent withdrawal.
authors.affiliation: Mental Health Service, Atlanta VA Medical Center, Decatur, GA 30033, USA. sbewing@emory.edu
authors.forename: Sarah
authors.initials: S
authors.lastname: Corcoran
authors.forename: Seth D
authors.initials: SD
authors.lastname: Norrholm
authors.forename: Bruce
authors.initials: B
authors.lastname: Cuthbert
authors.forename: Maya
authors.initials: M
authors.lastname: Sternberg
authors.forename: Jeff
authors.initials: J
authors.lastname: Hollis
authors.forename: Erica
authors.initials: E
authors.lastname: Duncan
mesh_terms: D000161:Acoustic Stimulation; D001767:Blinking / Q000187:drug effects / Q000502:physiology; D003042:Cocaine / Q000009:adverse effects*; D019970:Cocaine-Related Disorders / Q000378:metabolism / Q000503:physiopathology*; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology; D012008:Recurrence; D055139:Sensory Gating / Q000187:drug effects / Q000502:physiology*; D013375:Substance Withdrawal Syndrome / Q000378:metabolism / Q000503:physiopathology*
chemical_list: D003042:Cocaine