title: Associations among hypothalamus-pituitary-adrenal axis function, novelty seeking, and retention in methadone maintenance therapy for heroin dependency.
abstract: OBJECTIVE
  The efficacy of methadone maintenance therapy for heroin dependence is compromised by the low retention rate. Hypothalamus-pituitary-adrenal (HPA) axis function, which is associated with stress response, and novelty seeking (NS), a personality trait associated with low dopaminergic activity, may play roles in retention.
  
  
  METHODS
  We conducted a prospective study in which HPA axis function and NS were assessed by the dexamethasone suppression test and the Tridimensional Personality Questionnaire at baseline, respectively. The retention rate was assessed at the half- and 1-year points of methadone maintenance therapy.
  
  
  RESULTS
  A low suppression rate of dexamethasone suppression test (D%) was associated with a high level of NS. A low D% was associated with half-year dropout, whereas a high level of NS was associated with 1-year dropout. Survival analysis confirmed that D% and NS were significant time-dependent covariates for retention.
  
  
  CONCLUSIONS
  The findings showed that HPA axis function and NA were associated with retention at different time points.
authors.affiliation: From the Department of Psychiatry (S-HL, WTC, KCC, S-YL, IHL, PSC, TLY, R-BL, YKY), National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan; Addiction Research Center (S-HL, WTC, KCC, S-YL, IHL, PSC, TLY, R-BL, YKY), National Cheng Kung University, Tainan, Taiwan; Department of Psychiatry, Dou-Liou Branch, National Cheng Kung University Hospital (KCC, PSC), Yunlin, Taiwan; and Institute of Behavioral Medicine (R-BL), College of Medicine, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Shih-Hsien
authors.initials: SH
authors.lastname: Lin
authors.forename: Wei Tseng
authors.initials: WT
authors.lastname: Chen
authors.forename: Kao Chin
authors.initials: KC
authors.lastname: Chen
authors.forename: Sheng-Yu
authors.initials: SY
authors.lastname: Lee
authors.forename: I Hui
authors.initials: IH
authors.lastname: Lee
authors.forename: Po See
authors.initials: PS
authors.lastname: Chen
authors.forename: Tzung Lieh
authors.initials: TL
authors.lastname: Yeh
authors.forename: Ru-Band
authors.initials: RB
authors.lastname: Lu
authors.forename: Yen Kuang
authors.initials: YK
authors.lastname: Yang
mesh_terms: D000223:Adaptation, Psychological / Q000502:physiology; D000328:Adult; D003907:Dexamethasone; D005106:Exploratory Behavior / Q000502:physiology*; D005260:Female; D005938:Glucocorticoids; D006556:Heroin Dependence / Q000188:drug therapy / Q000378:metabolism / Q000523:psychology; D006801:Humans; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects / Q000378:metabolism; D008297:Male; D054539:Medication Therapy Management; D008691:Methadone / Q000494:pharmacology*; D008875:Middle Aged; D009294:Narcotics / Q000494:pharmacology; D058850:Opiate Substitution Treatment / Q000379:methods; D010352:Patient Dropouts / Q000706:statistics & numerical data; D010551:Personality / Q000502:physiology; D010552:Personality Assessment; D010913:Pituitary-Adrenal System / Q000187:drug effects / Q000378:metabolism; D011446:Prospective Studies; D016019:Survival Analysis; D014481:United States
chemical_list: D005938:Glucocorticoids; D009294:Narcotics; D003907:Dexamethasone; D008691:Methadone