Investigate patterns of methamphetamine use over time, specifically factors associated with remission from dependent and harmful patterns of use; and examine drug treatment and health/support service utilization pathways among people who use methamphetamine.
People who regularly use methamphetamine were recruited from nontreatment settings in Melbourne, Australia, in 2010, and followed up twice over 5 years. Trajectories of past-month methamphetamine use and methamphetamine dependence were mapped. Random-effects logistic regression modeling identified factors associated with these outcomes.
Overall, past-month methamphetamine use and methamphetamine dependence decreased among the cohort over the study period. Variability in methamphetamine use and dependence trajectories was observed; 56% of participants achieved past-month abstinence; however, 14% subsequently relapsed and 44% reported past-month use at every time-point. During the study period, 27% of participants were never classified methamphetamine-dependent, 30% remitted from dependence, and 23% were consistently classified dependent. Factors independently associated with past-month methamphetamine use included male sex and poor physical health. Factors independently associated with methamphetamine dependence included poor physical health, low self-perceived social support, current mental health medication prescription, and current engagement with drug treatment services for methamphetamine use. Engagement with treatment and health/support services remained low (12%–22%) over the study period.
Our findings indicate people who remit from methamphetamine dependence, reduce their frequency of use or cease entirely can maintain this over long periods. Initiatives addressing social determinants of health could be optimal for combating methamphetamine dependence. Community-based frontline service providers should be educated in relation to appropriately addressing methamphetamine use.
Behaviours and Health Risks Program, Burnet Institute (CL, PH, PD, BQ); Department of Epidemiology and Preventive Medicine, Monash University (CL, PD, BQ); Pre-hospital Emergency Care: Australia & New Zealand (PEC-ANZ) (DN); Department of Public Health, La Trobe University (PH); National Drug Research Institute, Faculty of Health Sciences, Curtin University (PH).
Send correspondence to Chloe Lanyon, MBBS, 85 Commercial Road, Melbourne, Victoria, 3004, Australia. E-mail: firstname.lastname@example.org
Received 4 April, 2018
Accepted 8 October, 2018
Funding: This research was supported by a financial grant provided by the Australian National Health and Medical Research Council (reference number 479208) and a Curtin University Research Fellowship (reference number 1300050).
Conflicts of interest: PH declares investigator-driven research funding from Gilead Sciences and Abbvie Pharmaceuticals for research unrelated to this study. PD received investigator-driven funding from Gilead Sciences and an untied educational grant from Indivior for work unrelated to this study. PD has provided unpaid consultancy to Mundipharma and Phebra for topics unrelated to this study. PD is an NHMRC Senior Research Fellow.