title: Effects of methylphenidate during emotional processing in amphetamine users: preliminary findings.
abstract: D-amphetamine (dAMPH) and methylphenidate (MPH) are stimulants used in the treatment of Attention Deficit Hyperactivity Disorder (ADHD). Preclinical studies have shown that in healthy animals, dAMPH induces dopamine (DA) dysfunction, as evidenced for instance by loss of DA levels and its transporters. It has also been suggested that DA plays an important role in emotional processing, and that altered DA-ergic intervention may modulate amygdala function. To explore the role of the DA system in emotional processing we examined emotional processing using functional magnetic resonance imaging (fMRI) in eight male recreational users of dAMPH and eight male healthy controls. We compared brain activation between both groups during an emotional face-processing task with and without an oral MPH challenge. All subjects were abstinent for at least 2 weeks during the baseline scan. The second scan was performed on the same day 1½ hours after receiving an oral dose of 35 mg MPH. A significant Valence*Group interaction (p = .037) indicated amygdala hyperreactivity to fearful facial expressions in dAMPH users that was robust against adjustment for age (p = .015). Furthermore, duration of amphetamine use in years was positively correlated with amygdala reactivity in dAMPH users (r = .76; p = .029). These exploratory findings are in line with previous findings suggesting that DA plays a role in emotional processing.
authors.affiliation: Department of Child and Adolescent Psychiatry, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.|Department of Child and Adolescent Psychiatry Triversum, Alkmaar, The Netherlands.
authors.forename: M A
authors.initials: MA
authors.lastname: Bottelier
authors.affiliation: Department of Radiology and Brain Imaging Center, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: M L J
authors.initials: ML
authors.lastname: Schouw
authors.affiliation: Department of Radiology and Brain Imaging Center, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: M B
authors.initials: MB
authors.lastname: de Ruiter
authors.affiliation: Program for Mood Disorders, Dept. of Psychiatry, Academic Medical Center, Amsterdam, The Netherlands.|Program for Mood and Anxiety Disorders, Department of Psychiatry, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: H G
authors.initials: HG
authors.lastname: Ruhe
authors.affiliation: Department of Child and Adolescent Psychiatry, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.|Academic Centre for Child and Adolescent Psychiatry, de Bascule, Amsterdam, The Netherlands.
authors.forename: R J L
authors.initials: RJ
authors.lastname: Lindauer
authors.affiliation: Department of Radiology and Brain Imaging Center, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. l.reneman@amc.uva.nl.|Department Radiology G1-222, Academic Medical center, University of Amsterdam, Brain Imaging Center Meibergdreef 9, 1105AZ, Amsterdam, The Netherlands. l.reneman@amc.uva.nl.
authors.forename: L
authors.initials: L
authors.lastname: Reneman
mesh_terms: D000284:Administration, Oral; D000328:Adult; D019969:Amphetamine-Related Disorders / Q000503:physiopathology* / Q000523:psychology; D001921:Brain / Q000187:drug effects* / Q000503:physiopathology; D001931:Brain Mapping; D018765:Dopamine Uptake Inhibitors / Q000008:administration & dosage*; D004644:Emotions / Q000187:drug effects / Q000502:physiology; D000066499:Facial Recognition / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008774:Methylphenidate / Q000008:administration & dosage*; D009434:Neural Pathways / Q000187:drug effects / Q000503:physiopathology; D009483:Neuropsychological Tests; D010775:Photic Stimulation; D011930:Reaction Time; D055815:Young Adult
chemical_list: D018765:Dopamine Uptake Inhibitors; D008774:Methylphenidate
keywords: Dextroamphetamine; Emotional lability; Face recognition; Methylphenidate; Neurotoxicity; fMRI