Characteristics and harms associated with injecting versus smoking methamphetamine among methamphetamine treatment...

To compare the characteristics and harms associated with injecting and smoking methamphetamine among methamphetamine treatment entrants.

A structured face-to-face interview was used to assess demographics, drug use patterns and harms [physical and mental health, psychological distress, psychotic symptoms, crime and human immunodeficiency virus (HIV) risk behaviour] among 400 methamphetamine treatment entrants in Sydney and Brisbane, Australia. Participants who had injected but not smoked methamphetamine in the month before treatment (n = 195, injectors) were compared to participants who had either: (a) injected and smoked (n = 90, injectors who smoke), or (b) smoked but not injected (n = 73, smokers), during this time.

In comparison with injectors, smokers were primarily non-injecting drug users, who were younger, more likely to be female and use ecstasy rather than heroin. After adjusting for these differences smokers were less dependent on methamphetamine than injectors, but they took the drug as often and had similarly high levels of psychological distress, poor physical and mental health, psychotic symptoms, sexual risk behaviour and criminal involvement. Injectors who smoked had a similar demographic and clinical profile to injectors, including comparable levels of needle sharing, but they used methamphetamine more often and had greater criminal involvement.

Within this treatment sample, smoking methamphetamine occurred among both long-standing injecting drug users and a comparatively younger group of non-injecting drug users. It was associated with less severe methamphetamine dependence than injecting, but more intense use patterns and similar levels of other harms.