“…Prevalence of methamphetamine use remains relatively low in the UK compared to other parts of Europe (Public Health England, 2017), with policy to reduce illicit and other harmful drug use currently focused on other amphetamine type substances such as speed, ecstasy and mephedrone (Home Office, 2017). At present, there is limited understanding of how best to prevent and treat harmful ATS use (Ciketic, Hayatbakhsh, Doran, Najman, & McKetin, 2012;Minozzi, Saulle, De Crescenzo, & Amato, 2016), or what critical turning points influence different pathways of ATS use over time (Alm, 2017;Beynon, 2009;Harris & Rhodes, 2018;Laub & Sampson, 1993;O'Donnell et al, 2018;Wojciechowski, 2018).…”