Characterizing users of new psychoactive substances using psychometric scales for risk-related behavior Annabel Vreeker a,b , Babette G. van der Burg a , Margriet van Laar a , Tibor M. Brunt a,c, ⁎ a Netherlands Institute of Mental Health and Addiction (Trimbos Institute), Department of Drug Monitoring & Policy, Utrecht, The Netherlands b Department of Psychology, Section Health, Medical, and Neuropsychology, Leiden University, Leiden, The Netherlands c Department of Psychiatry, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands HIGHLIGHTS • This manuscript shows that NPS users are more impulsive and show a higher level of sensation seeking. • This manuscript shows that NPS users have more peers who use substances and have lower risk perception of drug use. • In conclusion, NPS users show more risk-related behavior compared to non-drug users and even illicit drug users. abstract article info Article history: Received 19 October 2016 Received in revised form 26 January 2017 Accepted 8 February 2017 Available online 10 February 2017 Introduction: Studies investigating risk-related behavior in relation to new psychoactive substance (NPS) use are sparse. The current study investigated characteristics of NPS users by comparing risk-related behavior of NPS users to that of illicit drugs (ID) users and licit substances users and non-users (NLC) users. Methods: In this cross-sectional study we included 528 individuals across an age range of 18–72 years. Using a web-based questionnaire we collected self-report data on substance use, sensation seeking, impulsivity, peer substance use and risk perception of substance use. Results: NPS and ID users had a higher level of sensation seeking compared to NLC users (NPS users: p b 0.001; ID users: p b 0.001). NPS users (p b 0.001), but not ID users (p = 0.16), had increased levels of impulsivity compared to NLC users. NPS users had significantly higher scores for sensation seeking (F 1,423 = 51.52, p b 0.001) and im- pulsivity (F 1,423 = 6.15, p = 0.01) compared to ID users. Additionally, NPS users had significantly more peers who use substances compared to ID and NLC users. Also, NPS and ID users had lower risk perception for most sub- stances than NLC users. NPS users had lower risk perception for most substances than ID users. Conclusions: The findings highlight that NPS users show substantial more risk-related behavior than both ID and NLC users. Therefore, NPS users might be considered as a distinctive group of substance users that need another approach in terms of prevention. © 2017 Elsevier Ltd. All rights reserved. Keywords: New psychoactive substances Illicit drugs Risk-related behavior Sensation seeking Impulsivity Peer substance use 1. Introduction The international drug market has undergone radical changes dur- ing the past years, both in supply as well as consumption. New psycho- active substances (NPS), also referred to as research chemicals, designer drugs, or legal highs, are substances with a psychoactive effect that are recently added to the consumer market and used as a drug. NPS often imitate the effects of existing illicit drugs such as cocaine, amphet- amines, ecstasy or cannabis and chemically resemble their illicit coun- terparts. However, because the chemical structure of these substances differs slightly from that of illicit substances, new substances are creat- ed, often not yet controlled by legislation. An ever-growing list of NPS has been reported by the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) of N 450 different NPS between 2005 and 2014, with more than half of those reported in the last three years (EMCDDA, 2014; EMCDDA, 2015). These developments paralleled with a growing number of research reports about effects and risks of NPS. For instance, psychopharmaco- logical studies have tried to analyse what subjective psychological and physical effects can be attributed to some NPS (Freeman et al., 2012; Linsen et al., 2015; Winstock et al., 2011b; Bäckberg, Beck, Hultén, Rosengren-Holmberg, & Helander, 2014; Bernson-Leung, Leung, & Kumar, 2014; Borek & Holstege, 2012; de Jong, van Vuren, Niesink, & Brunt, 2013; Kueppers & Cooke, 2015; Stoica & Felthous, 2013). In Addictive Behaviors 70 (2017) 72–78 ⁎ Corresponding author at: Trimbos Institute, Department of Drug Monitoring & Policy, PO box 725, 3500 AS Utrecht, The Netherlands. E-mail address: tbrunt@trimbos.nl (T.M. Brunt). http://dx.doi.org/10.1016/j.addbeh.2017.02.010 0306-4603/© 2017 Elsevier Ltd. All rights reserved. Contents lists available at ScienceDirect Addictive Behaviors journal homepage: www.elsevier.com/locate/addictbeh