title: Comparison of cognitive performance in methadone maintenance patients with and without current cocaine dependence.
abstract: BACKGROUND
  There is evidence for psychomotor and cognitive performance impairment in methadone maintenance patients (MMP), as well as in individuals with current cocaine dependence. It is unknown whether MMP with concurrent cocaine dependence perform worse on tests of cognitive function than MMP without cocaine dependence.
  
  
  METHODS
  Performance was compared between MMP with and without current cocaine dependence (MMP/CD+; N = 53 and MMP/CD-; N = 24) on a standard battery of tasks designed to measure psychomotor performance, attention, episodic and working memory, and executive function.
  
  
  RESULTS
  Participant characteristics were mostly similar across groups. However, the MMP/CD+ group had a shorter duration of methadone treatment, and a larger percentage of participants with self-reported 30-day poly-substance abuse and positive urine drug tests on the day of cognitive testing. There were no differences between the groups on measures of balance, psychomotor coordination, divided attention, working memory, most measures of episodic memory, or executive function. Relative to MMP/CD-, MMP/CD+ showed significant impairment on select measures of psychomotor performance/attention (simple reaction time and trail-making test A) and episodic memory (higher false alarm rates on recognition memory).
  
  
  CONCLUSIONS
  The absence of differences between MMP/CD+ and MMP/CD- on measures of higher order cognitive functions, and the relatively small magnitude between-group differences on other measures suggest that current cocaine dependence, in the absence of cocaine intoxication, is unlikely to be associated with clinically meaningful increases in performance impairment in MMP.
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, 5510 Nathan Shock Drive, Baltimore, MD 21224, United States.
authors.forename: Porche K
authors.initials: PK
authors.lastname: Henry
authors.forename: Annie
authors.initials: A
authors.lastname: Umbricht
authors.forename: Bethea A
authors.initials: BA
authors.lastname: Kleykamp
authors.forename: Ryan
authors.initials: R
authors.lastname: Vandrey
authors.forename: Eric C
authors.initials: EC
authors.lastname: Strain
authors.forename: George E
authors.initials: GE
authors.lastname: Bigelow
authors.forename: Miriam Z
authors.initials: MZ
authors.lastname: Mintzer
mesh_terms: D000328:Adult; D001288:Attention; D019970:Cocaine-Related Disorders / Q000150:complications / Q000523:psychology* / Q000534:rehabilitation; D003071:Cognition; D056344:Executive Function; D005260:Female; D006556:Heroin Dependence / Q000150:complications / Q000523:psychology* / Q000534:rehabilitation; D006801:Humans; D008297:Male; D008568:Memory; D008875:Middle Aged; D009483:Neuropsychological Tests; D058850:Opiate Substitution Treatment / Q000523:psychology*; D011597:Psychomotor Performance; D011930:Reaction Time