title: Emotion dysregulation and amygdala dopamine D2-type receptor availability in methamphetamine users.
abstract: BACKGROUND
  Individuals who use methamphetamine chronically exhibit emotional and dopaminergic neurochemical deficits. Although the amygdala has an important role in emotion processing and receives dopaminergic innervation, little is known about how dopamine transmission in this region contributes to emotion regulation. This investigation aimed to evaluate emotion regulation in subjects who met DSM-IV criteria for methamphetamine dependence, and to test for a relationship between self-reports of difficulty in emotion regulation and D2-type dopamine receptor availability in the amygdala.
  
  
  METHODS
  Ninety-four methamphetamine-using and 102 healthy-control subjects completed the Difficulties in Emotion Regulation Scale (DERS); 33 of those who used methamphetamine completed the Addiction Severity Index (ASI). A subset of 27 methamphetamine-group and 20 control-group subjects completed positron emission tomography with [(18)F]fallypride to assay amygdala D2-type dopamine receptor availability, measured as binding potential (BPND).
  
  
  RESULTS
  The methamphetamine group scored higher than the control group on the DERS total score (p<0.001), with DERS total score positively correlated with the Drug Composite Score on the ASI (p=0.02) in the methamphetamine group. The DERS total score was positively correlated with amygdala BPND in both groups and the combined group of participants (combined: r=0.331, p=0.02), and the groups did not differ in this relationship.
  
  
  CONCLUSIONS
  These findings highlight problems with emotion regulation linked to methamphetamine use, possibly contributing to personal and interpersonal behavioral problems. They also suggest that D2-type dopamine receptors in the amygdala contribute to emotion regulation in both healthy and methamphetamine-using subjects.
authors.affiliation: Department of Psychiatry and Biobehavioral Sciences, Los Angeles, CA 90024, USA; Department of Research, VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA.
authors.forename: Kyoji
authors.initials: K
authors.lastname: Okita
authors.affiliation: Department of Psychiatry and Biobehavioral Sciences, Los Angeles, CA 90024, USA.
authors.forename: Dara G
authors.initials: DG
authors.lastname: Ghahremani
authors.affiliation: Addiction Imaging Research Group, Centre for Addiction and Mental Health, Toronto, Ontario M5T 1R8, Canada; Department of Psychiatry, University of Toronto, Toronto, Ontario M5T 1R8, Canada.
authors.forename: Doris E
authors.initials: DE
authors.lastname: Payer
authors.affiliation: Department of Molecular and Medical Pharmacology, Los Angeles, CA 90024, USA; Department of Research, VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA.
authors.forename: Chelsea L
authors.initials: CL
authors.lastname: Robertson
authors.affiliation: Department of Psychiatry and Biobehavioral Sciences, Los Angeles, CA 90024, USA.
authors.forename: Andy C
authors.initials: AC
authors.lastname: Dean
authors.affiliation: Department of Research, VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA; Department of Physics, University of California Irvine, Irvine, CA 92697, USA.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Mandelkern
authors.affiliation: Department of Psychiatry and Biobehavioral Sciences, Los Angeles, CA 90024, USA; Department of Molecular and Medical Pharmacology, Los Angeles, CA 90024, USA; Brain Research Institute, University of California Los Angeles, Los Angeles, CA 90024, USA; Department of Research, VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA. Electronic address: elondon@mednet.ucla.edu.
authors.forename: Edythe D
authors.initials: ED
authors.lastname: London
mesh_terms: D000328:Adult; D019969:Amphetamine-Related Disorders / Q000378:metabolism*; D000679:Amygdala / Q000378:metabolism*; D001549:Benzamides / Q000378:metabolism; D016022:Case-Control Studies; D039721:Diagnostic and Statistical Manual of Mental Disorders; D004298:Dopamine / Q000378:metabolism; D004644:Emotions; D005260:Female; D005462:Fluorine Radioisotopes; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008694:Methamphetamine / Q000009:adverse effects*; D008875:Middle Aged; D059906:Neuroimaging; D049268:Positron-Emission Tomography / Q000379:methods; D011869:Radioligand Assay; D017448:Receptors, Dopamine D2 / Q000378:metabolism*
chemical_list: D001549:Benzamides; D005462:Fluorine Radioisotopes; D017448:Receptors, Dopamine D2; D008694:Methamphetamine; C574003:fallypride; D004298:Dopamine
keywords: Amygdala; Dopamine; Emotion dysregulation; Methamphetamine; PET; [(18)F]Fallypride