title: Reduced Prefrontal Cortex Hemodynamic Response in Adults with Methamphetamine Induced Psychosis: Relevance for Impulsivity.
abstract: Patients with methamphetamine abuse/dependence often exhibit high levels of impulsivity, which may be associated with the structural abnormalities and functional hypoactivities observed in the frontal cortex of these subjects. Although near-infrared spectroscopy (NIRS) is a simple and non-invasive method for characterizing the clinical features of various psychiatric illnesses, few studies have used NIRS to directly investigate the association between prefrontal cortical activity and inhibitory control in patients with methamphetamine-induced psychosis (MAP). Using a 24-channel NIRS system, we compared hemodynamic responses during the Stroop color-word task in 14 patients with MAP and 21 healthy controls matched for age, sex and premorbid IQ. In addition, we used the Barrett Impulsivity Scale-11 (BIS-11) to assess impulsivity between subject groups. The MAP group exhibited significantly less activation in the anterior and frontopolar prefrontal cortex accompanied by lower Stroop color-word task performance, compared with controls. Moreover, BIS-11 scores were significantly higher in the MAP group, and were negatively correlated with the hemodynamic responses in prefrontal cortex. Our data suggest that reduced hemodynamic responses in the prefrontal cortex might reflect higher levels of impulsivity in patients with MAP, providing new insights into disrupted inhibitory control observed in MAP.
authors.affiliation: Department of Psychiatry, Nara Medical University School of Medicine, Kashihara, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Yamamuro
authors.affiliation: Department of Psychiatry, Nara Medical University School of Medicine, Kashihara, Japan.
authors.forename: Sohei
authors.initials: S
authors.lastname: Kimoto
authors.affiliation: Faculty of Nursing, Nara Medical University School of Medicine, Kashihara, Japan.
authors.forename: Junzo
authors.initials: J
authors.lastname: Iida
authors.affiliation: Department of Psychiatry, Nara Medical University School of Medicine, Kashihara, Japan.
authors.forename: Naoko
authors.initials: N
authors.lastname: Kishimoto
authors.affiliation: Department of Psychiatry, Nara Medical University School of Medicine, Kashihara, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Nakanishi
authors.affiliation: Department of Psychiatry, Nara Medical University School of Medicine, Kashihara, Japan.
authors.forename: Shohei
authors.initials: S
authors.lastname: Tanaka
authors.affiliation: Department of Psychiatry, Nara Medical University School of Medicine, Kashihara, Japan.
authors.forename: Toyosaku
authors.initials: T
authors.lastname: Ota
authors.affiliation: Department of Psychiatry, Nara Medical University School of Medicine, Kashihara, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Makinodan
authors.affiliation: Department of Psychiatry, Nara Medical University School of Medicine, Kashihara, Japan.
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Kishimoto
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D005260:Female; D006439:Hemodynamics; D006801:Humans; D007175:Impulsive Behavior / Q000187:drug effects*; D008297:Male; D008694:Methamphetamine / Q000633:toxicity*; D008875:Middle Aged; D017397:Prefrontal Cortex / Q000503:physiopathology*; D011618:Psychotic Disorders / Q000209:etiology / Q000503:physiopathology* / Q000523:psychology; D019265:Spectroscopy, Near-Infrared
chemical_list: D008694:Methamphetamine