Tū Whakaruruhau: the evaluation of treatment outcomes for methamphetamine dependence in Aotearoa, New Zealand – study protocol for a prospective longitudinal cohort study and longitudinal qualitative study

Abstract Background: Methamphetamine is the second most used illicit drug in Aotearoa New Zealand, after cannabis. Regular and heavy users of methamphetamine are likely to develop methamphetamine use disorder (MUD), and significant health and psychiatric harm. Effective treatments for MUD are limited, and relapses are common. Tū Whakaruruhau is a programme of research that aims to understand what treatment approaches are effective in managing MUD and related physical and psychological harms, in New Zealand. Methods: Tū Whakaruruhau comprises two studies.