title: The role of age, genotype, sex, and route of acute and chronic administration of methylphenidate: a review of its locomotor effects.
abstract: Children with attention deficit hyperactivity disorder (ADHD) are treated for extended periods of time with the psychostimulant methylphenidate (MPD). The psychostimulants cocaine, amphetamine, and MPD exhibit similar structural configuration and pharmacological profile. The consequence of the long-term use of psychostimulants such as MPD as treatment for ADHD in the developing brain of children is unknown. Repeated treatment with psychostimulants has been shown to elicit adverse effects in behavior, such as dependence, paranoia, schizophrenia, and behavioral sensitization. Behavioral sensitization and cross-sensitization between two drugs are used as experimental markers to determine the potential of a drug to develop dependence/addiction. Although there are many reviews written about behavioral sensitization involving psychostimulants, scarcely any have focused specifically on MPD-elicited behavioral sensitization and cross-sensitization with other psychostimulants. Moreover, the response to MPD and the expression of ADHD vary among females and males and among different populations due to genetic variability. Since the interpretation and synthesis of the data reported are controversial, this review focuses on the adverse effects of MPD and the role of age, sex, and genetic composition on the acute and chronic effects of MPD, such as MPD-elicited behavioral sensitization and cross-sensitization with amphetamine in animal models. Animal models of drug-induced locomotor stimulation, particularly locomotor sensitization, can be used to understand the mechanisms underlying human drug-induced dependence.
authors.affiliation: Department of Neurobiology and Anatomy, The University of Texas Medical School at Houston, P.O. Box 20708, Houston, TX 77225, USA. Nachum.Dafny@uth.tmc.edu
authors.forename: Nachum
authors.initials: N
authors.lastname: Dafny
authors.forename: Pamela B
authors.initials: PB
authors.lastname: Yang
mesh_terms: D000367:Age Factors; D019969:Amphetamine-Related Disorders / Q000235:genetics / Q000503:physiopathology*; D000818:Animals; D000697:Central Nervous System Stimulants / Q000008:administration & dosage / Q000009:adverse effects*; D002648:Child; D002653:Child Behavior Disorders / Q000139:chemically induced* / Q000503:physiopathology; D002675:Child, Preschool; D004195:Disease Models, Animal; D004351:Drug Resistance / Q000235:genetics*; D004357:Drug Synergism; D005260:Female; D006801:Humans; D008297:Male; D008774:Methylphenidate / Q000008:administration & dosage / Q000009:adverse effects*; D009043:Motor Activity / Q000187:drug effects* / Q000502:physiology; D012727:Sex Characteristics
chemical_list: D000697:Central Nervous System Stimulants; D008774:Methylphenidate