The relationship between crystalline methamphetamine use and methamphetamine dependence.
BACKGROUND
The aim of the current study was to determine whether crystalline methamphetamine users are more dependent on methamphetamine than people who use other forms of the drug, and if so, whether this could be accounted for by their methamphetamine use history.


METHODS
A structured face-to-face interview was used to assess drug use patterns and demographics among a convenience sample of 309 regular methamphetamine users from Sydney, Australia. Dependence on methamphetamine in the past year was measured using the Severity of Dependence Scale. The use of crystalline methamphetamine in the past year was confirmed using a photographic identification sheet.


RESULTS
Participants who had used crystalline methamphetamine in the past year were significantly more likely to be dependent on methamphetamine than participants who took only other forms of methamphetamine during this time (61% versus 39%). Methamphetamine dependence was also associated with injecting or smoking methamphetamine (67% and 58%, respectively versus 30% for intranasal or oral use), using methamphetamine more than weekly (68% versus 34%), having used the drug for more than 5 years (61% versus 36%), and having used 'base' methamphetamine in the past year (59% versus 39%). Crystalline methamphetamine use remained significantly associated with methamphetamine dependence after adjusting for these patterns of methamphetamine use.


CONCLUSIONS
Methamphetamine users who took crystalline methamphetamine in the past year were more likely to be dependent than methamphetamine users who had not taken the crystalline form of the drug during this time.
McKetin
Rebecca
R
National Drug and Alcohol Research Centre, University of New South Wales, Sydney, 2052 NSW, Australia. r.mcketin@unsw.edu.au
Kelly
Erin
E
McLaren
Jennifer
J
D000293:Adolescent; D000328:Adult; D000697:Central Nervous System Stimulants / Q000008:administration & dosage; D004333:Drug Administration Routes; D005260:Female; D006801:Humans; D008297:Male; D008694:Methamphetamine / Q000008:administration & dosage; D008875:Middle Aged; D012720:Severity of Illness Index; D019966:Substance-Related Disorders / Q000175:diagnosis* / Q000453:epidemiology
D000697:Central Nervous System Stimulants; D008694:Methamphetamine