Use trajectories of amphetamine-type stimulants (ATS) in Shanghai, China

Although amphetamine-type stimulant (ATS) use is an important issue that has caused growing concerns in China as well as other countries, the knowledge of long-term patterns of ATS use in China is limited. This study explored long-term patterns of ATS use in Shanghai, China, and compared the differences by ATS use trajectory groups, seeking to identify risk factors that have implications for the development of targeted intervention programs.

A total of 377 ATS users were recruited from the Compulsory Isolation Center for Drug Rehabilitation in Shanghai. Group-based trajectory modeling was applied to identify distinctive trajectories of ATS use over 8 years at the time of interviews conducted in 2012. The mean number of days using ATS per month over a year from years 2005 to 2012 was analyzed with a censored normal model.

Three distinctive groups were identified: high-use (19.1%), low-use (66.0%), and increasing-use (14.9%). Relative to the low-use group, the high-use and increasing-use groups were more likely to report having used opiate-type drugs and to have more craving experiences. Psychiatric symptoms following ATS use were frequently reported, with ATS users in the increasing-use and high-use groups more likely to report depression symptoms and suicide behaviors compared to the low-use group. The low-use and increasing-use groups reported more months in drug abuse treatment programs compared to the high-use group.

Addressing ATS use should take into consideration patients' use-related psychiatric symptoms as well as other risk factors, particularly among those with persistent high-level ATS use trajectories.