Research Article A Systems Dynamic Model for Drug Abuse and Drug-Related Crime in the Western Cape Province of South Africa Farai Nyabadza and Lezanie Coetzee Department of Mathematical Sciences, Stellenbosch University, Private Bag X1, Matieland 7600, South Africa Correspondence should be addressed to Farai Nyabadza; f.nyaba@gmail.com Received 12 October 2016; Accepted 26 February 2017; Published 7 May 2017 Academic Editor: Sanjeewa Perera Copyright © 2017 Farai Nyabadza and Lezanie Coetzee. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Te complex problem of drug abuse and drug-related crimes in communities in the Western Cape province cannot be studied in isolation but through the system they are embedded in. In this paper, a theoretical model to evaluate the syndemic of substance abuse and drug-related crimes within the Western Cape province of South Africa is constructed and explored. Te dynamics of drug abuse and drug-related crimes within the Western Cape are simulated using STELLA sofware. Te simulation results are consistent with the data from SACENDU and CrimeStats SA, highlighting the usefulness of such a model in designing and planning interventions to combat substance abuse and its related problems. 1. Introduction Te complex problems that society and researchers face in current times leave no space for one-dimensional thinking with regard to interventions. Community level problems cannot be viewed in isolation. In fact, they need to be viewed within the system they are embedded in. Substance abuse is one of the complex challenges that researchers in diferent felds are battling to understand and analyse, especially with regard to the ripple efects it has within communities in terms of drug-related crimes and the spread of sexual transmitted infections. Systems thinking and system dynamics open up new avenues for cross-discipline research. Tis enables the social sciences and natural sciences to integrate descriptive and quantitative research in order to inform communities and assist stakeholders and policy makers at the same time. South Africa’s geographic location, lax border controls, a weak criminal justice system, modern telecommunications, banking systems, and international trade links with South America, North America, Asia, and Europe endanger the country to transhipment of drugs [1]. Even though substance abuse is a national menace in South Africa, it is found to be concentrated within the Western Cape [2–4]. According to the Department of Community Safety [2], more than a third (35%) of the crimes in the Western Cape are due to substance abuse. Tis explains the high contribution the Western Cape has had on the national drug-related crime statistics in the past decade (consistently higher that 30%). In the 2013/2014 report on the Western Cape policing needs and priorities (PNP), it was noted that substance abuse is the motivation behind 22% of committed crimes [2]. Te dynamic evolution of drug abuse within communities is synonymous to that of infectious diseases; see, for instance [5–9] and the references cited therein, where initiation of the susceptible population is dependent on interaction between the drug users and the population at risk. White and Gorman [10] explained the complex relationship between drugs and crime through three models: “(1) substance use leads to crime, (2) crime leads to substance use, and (3) the relationship is either coincidental or explained by a set of common causes.” Tese models explain the diferent reasons why crimes are being committed by drug-using ofenders. Although a single model cannot explain the entire drug-crime system, the relationship between drugs and crime involves a broad spectrum of social, political, and economic forces, the environment of the individuals abusing substances, and the biological processes driving human behaviour [11]. Hindawi Computational and Mathematical Methods in Medicine Volume 2017, Article ID 4074197, 13 pages https://doi.org/10.1155/2017/4074197