title: Chronic methylphenidate treatment during early life is associated with greater ethanol intake in socially isolated rats.
abstract: BACKGROUND
  Methylphenidate (MPH) is a stimulant prescribed to treat attention-deficit/ hyperactivity disorder. Its primary mechanism of action is in the dopamine system, alterations of which are associated with vulnerability to alcohol abuse. There are concerns that juvenile MPH treatment may influence adult drinking behavior. This study examined the interaction of MPH treatment and environmental rearing conditions, which are known to independently influence ethanol (EtOH) drinking behavior, on anxiety-like behavior and vulnerability to alcohol abuse in a juvenile rodent model.
  
  
  METHODS
  Male Sprague-Dawley rats were housed in enriched, standard, or isolated conditions for 4 weeks, starting at postnatal day 21. Rats were concurrently treated with 8 mg/kg/d MPH or saline, delivered via osmotic minipump. Anxiety-like behavior was determined at the end of the treatment session, and 5 weeks later. After MPH treatment, rats were exposed to a 2-bottle choice EtOH drinking procedure that lasted 3 weeks.
  
  
  RESULTS
  Early life chronic MPH treatment was associated with greater EtOH intake and greater EtOH preference, but only in socially isolated animals. Isolated animals had greater levels of anxiety-like behavior than standard-housed or enriched animals after 4 weeks of exposure to the housing conditions, a difference that persisted even after all animals had been individually housed for an additional 5 weeks and exposed to EtOH.
  
  
  CONCLUSIONS
  These results suggest that early life MPH treatment may increase vulnerability to EtOH drinking in adulthood in a subset of the population. Additionally, this study highlights the importance of early rearing condition for establishing long-lasting behavioral phenotypes. Environmental histories should be considered when prescribing MPH treatment to young children.
authors.affiliation: Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston Salem, North Carolina.
authors.forename: Kathryn E
authors.initials: KE
authors.lastname: Gill
authors.forename: Ann M
authors.initials: AM
authors.lastname: Chappell
authors.forename: Thomas J R
authors.initials: TJ
authors.lastname: Beveridge
authors.forename: Linda J
authors.initials: LJ
authors.lastname: Porrino
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Weiner
mesh_terms: D000367:Age Factors; D000428:Alcohol Drinking / Q000523:psychology*; D000818:Animals; D000697:Central Nervous System Stimulants / Q000494:pharmacology; D002755:Choice Behavior / Q000187:drug effects; D008297:Male; D008774:Methylphenidate / Q000008:administration & dosage* / Q000494:pharmacology*; D051381:Rats; D012934:Social Isolation / Q000523:psychology*
chemical_list: D000697:Central Nervous System Stimulants; D008774:Methylphenidate
keywords: Ethanol Drinking; Methylphenidate; Rearing Environment; Social Isolation