title: Similarity and Difference in Drug Addiction Process Between Heroin- and Methamphetamine-Dependent Users.
abstract: This study aimed to compare the drug addiction process between Chinese heroin- and methamphetamine (MA)-dependent users via a modified 4-stage addiction model (experimentation, occasional use, regular use, and compulsive use).
  
  
  
  A descriptive study was conducted among 683 eligible participants. In the statistical analysis, we selected 340 heroin- and 295 MA-dependent users without illicit drug use prior to onset of heroin or MA use.
  
  
  
  The addiction process of heroin-dependent users was shorter than that of MA-dependent users, with shorter transitions from the onset of drug-use to the first drug craving (19.5 vs. 50.0 days), regular use (30.0 vs. 60.0 days), and compulsive use (50.0 vs. 85.0 days). However, no significant differences in the addiction process were observed in frequency of drug administration, except that heroin users reported more administrations of the drug (20.0 vs. 15.0) before progressing to the stage of compulsive drug use. A larger proportion of regular heroin users progressed to use illicit drugs recklessly than did MA users. Most heroin and MA users reported psychological dependence as their primary motivation for compulsive drug use, but more heroin users selected uncomfortable symptoms upon ceasing drug use as further reason to continue.
  
  
  
  Our results suggest that typical heroin and MA users may experience a similar four-stage addiction process, but MA users might undergo a longer addiction process (in days). More research is necessary to further explore factors influencing the drug addiction process.
authors.affiliation: a School of Public Health , Guizhou Medical University , Gui'an New Area, China.|b School of Public Health , Peking University , Beijing , China.
authors.forename: Ziyun
authors.initials: Z
authors.lastname: Wang
authors.affiliation: b School of Public Health , Peking University , Beijing , China.|c Shandong Center for Disease Control and Prevention , Shandong , China.
authors.forename: Wei-Xiu
authors.initials: WX
authors.lastname: Li
authors.affiliation: d National Institute on Drug Dependence, Peking University , Beijing , China.
authors.forename: Liu
authors.initials: L
authors.lastname: Zhi-Min
mesh_terms: D000328:Adult; D019969:Amphetamine-Related Disorders / Q000453:epidemiology / Q000523:psychology*; D016739:Behavior, Addictive / Q000523:psychology; D002681:China / Q000453:epidemiology; D018450:Disease Progression; D005260:Female; D006556:Heroin Dependence / Q000453:epidemiology / Q000523:psychology*; D006801:Humans; D008297:Male; D011795:Surveys and Questionnaires
keywords: Drug dependence; drug addiction process; drug use career; heroin; methamphetamine