The public health evidence-base on novel psychoactive substance use:Scoping review with narrative synthesis of selected bodies of evidence

Background: This review aimed to address what was known about the public health burden associated with novel psychoactive substances (NPS) use, and the effectiveness of responses targeting NPS use and/or associated problems. Methods: Relevant literature was identified through a range of searches covering the period from January 2006 to June 2016. Data synthesis was undertaken in three stages. Firstly we mapped the evidence available in order to characterise the literature according to a set of analytic categories developed a priori. Secondly, we identified evidence gaps from a set of a priori research questions. Finally, we then undertook a narrative synthesis of selected bodies of evidence, interpreting data using a conceptual framework specifically designed for use in this review. Results: 995 articles were included in the scoping review with the majority being case reports/ series on individual level adverse effects due to NPS use. We synthesised UK data from 29 surveys and 7 qualitative studies, and international data in 10 systematic reviews on harms associated with NPS use, and 17 evaluations of policy responses. We found little data on risk factors, harms associated with long term NPS use, and interventions. Conclusion: In all cases we found the available evidence to be at an early stage of development.