title: Cognitive function during early abstinence from opioid dependence: a comparison to age, gender, and verbal intelligence matched controls.
abstract: BACKGROUND
  Individuals with opioid dependence have cognitive deficits during abuse period in attention, working memory, episodic memory, and executive function. After protracted abstinence consistent cognitive deficit has been found only in executive function. However, few studies have explored cognitive function during first weeks of abstinence. The purpose of this study was to study cognitive function of individuals with opioid dependence during early abstinence. It was hypothesized that cognitive deficits are pronounced immediately after peak withdrawal symptoms have passed and then partially recover.
  
  
  METHODS
  Fifteen patients with opioid dependence and fifteen controls matched for, age, gender, and verbal intelligence were tested with a cognitive test battery When patients performed worse than controls correlations between cognitive performance and days of withdrawal, duration of opioid abuse, duration of any substance abuse, or opioid withdrawal symptom inventory score (Short Opiate Withdrawal Scale) were analyzed.
  
  
  RESULTS
  Early abstinent opioid dependent patients performed statistically significantly worse than controls in tests measuring complex working memory, executive function, and fluid intelligence. Their complex working memory and fluid intelligence performances correlated statistically significantly with days of withdrawal.
  
  
  CONCLUSIONS
  The results indicate a rather general neurocognitive deficit in higher order cognition. It is suggested that cognitive deficit during early abstinence from opioid dependence is related to withdrawal induced neural dysregulation in the prefrontal cortex and is partly transient.
authors.affiliation: Psychiatric Unit for Drug Dependence, Department of Psychiatry, Helsinki University Central Hospital, Finland. pekka.rapeli@kolumbus.fi
authors.forename: Pekka
authors.initials: P
authors.lastname: Rapeli
authors.forename: Reetta
authors.initials: R
authors.lastname: Kivisaari
authors.forename: Taina
authors.initials: T
authors.lastname: Autti
authors.forename: Seppo
authors.initials: S
authors.lastname: Kähkönen
authors.forename: Varpu
authors.initials: V
authors.lastname: Puuskari
authors.forename: Olga
authors.initials: O
authors.lastname: Jokela
authors.forename: Hely
authors.initials: H
authors.lastname: Kalska
mesh_terms: D000328:Adult; D000367:Age Factors; D003072:Cognition Disorders / Q000175:diagnosis* / Q000503:physiopathology; D005260:Female; D006801:Humans; D007361:Intelligence Tests / Q000706:statistics & numerical data; D008297:Male; D008569:Memory Disorders / Q000175:diagnosis / Q000503:physiopathology; D008959:Models, Neurological; D009483:Neuropsychological Tests / Q000706:statistics & numerical data*; D009293:Opioid-Related Disorders / Q000523:psychology* / Q000534:rehabilitation*; D010555:Personality Inventory; D017397:Prefrontal Cortex / Q000503:physiopathology; D012737:Sex Factors; D013375:Substance Withdrawal Syndrome / Q000175:diagnosis* / Q000503:physiopathology; D013997:Time Factors