Which individual, social and environmental influences shape key phases in the amphetamine type stimulant use trajectory? A systematic narrative review and thematic synthesis of the qualitative literature.

Background and aims: There is limited evidence on what shapes amphetamine‐type stimulant (ATS) use trajectories. This systematic narrative review and qualitative synthesis aimed to identify individual, social and environmental influences shaping key phases in the ATS use trajectory: initiation, continuation, increase/relapse and decrease/abstinence. Methods: MEDLINE, PsycINFO, EMBASE, and PROQUEST (social science premium collection) were searched from 2000 to 2018. Studies of any qualitative design were eligible for inclusion. Extracted data were analysed according to four key phases within drug pathways, and then cross‐analysed for individual, social and environmental influences. Results: Forty‐four papers based on 39 unique studies were included, reporting the views of 1879 ATS users. Participants were aged 14–58 years, from varied socio‐economic and demographic groups, and located in North America, Europe, Australasia and South East Asia. Reasons for initiation included: to boost performance at work and in sexual relationships, promote a sense of social 'belonging' and help manage stress. Similar reasons motivated continued use, combined with the challenge of managing withdrawal effects in long‐term users. Increased tolerance and/or experiencing a critical life event contributed to an increase in use. Reasons for decrease focused on: increased awareness of the negative health impacts of long‐term use, disconnecting from social networks or relationships and financial instability. Conclusions: Amphetamine‐type stimulant users are a highly diverse population, and their drug use careers are shaped by a complex dynamic of individual, social and environmental factors. Tailored, joined‐up interventions are needed to address users' overlapping economic, health and social care needs in order to support long‐term abstinence. [ABSTRACT FROM AUTHOR]