The Effect of Marijuana Legalization on the Trajectories of Hard Drug–Related Hospitalizations: A Growth Curve Analysis of the County-Level State Inpatient Database in Washington, 2009–2015

• Author: Seong-min Park,Shon M. Reed,Jay J. Shen,Ji Won Yoo
• Published date: 01 July 2020
• Date: 01 July 2020
• DOI: http://doi.org/10.1177/0022042620912695
• Subject Matter: Articles

https://doi.org/10.1177/0022042620912695

Journal of Drug Issues

2020, Vol. 50(3) 273 –285

© The Author(s) 2020

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DOI: 10.1177/0022042620912695

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Article

The Effect of Marijuana Legalization

on the Trajectories of Hard Drug–

Related Hospitalizations: A Growth

Curve Analysis of the County-

Level State Inpatient Database in

Washington, 2009–2015

Seong-min Park1, Jay J. Shen1, Ji Won Yoo1,

and Shon M. Reed1

Abstract

Two antithetical arguments have raised controversies over the effect of recreational marijuana

legalization on hard drug use. The gateway perspective posits that marijuana use diffuses hard

drug use; however, recent studies argue that marijuana legalization displaces hard drug use.

This study examines these conflicting arguments by investigating temporal patterns of hard

drug–related hospitalizations (HDHs) before and after marijuana legalization. Using county-

level State Inpatient Database data from Washington State for the years 2009–2015, along with

other federal data sources, this study assesses temporal changes in HDH using growth curve

modeling. Initial findings show support for the displacement perspective, though controlling

for other county-level factors (education and economic change) indicates that the legalization

of recreational marijuana may be a gateway toward harder drugs. Considering the economic

situation of the United States during the study period, this study concludes that marijuana

legalization functioned as a gateway toward increased hard drug use.

Keywords

marijuana legalization, gateway perspective, displacement perspective, hard drug–related

hospitalization

Introduction

Since the states of Colorado and Washington legalized the recreational use of marijuana in 2013,

state policies regarding recreational marijuana have rapidly changed across the United States

(Livingston et al., 2017; Sokoya et al., 2018). Following Michigan’s legalization in 2018, a total

of nine states1 have fully legalized marijuana and regulate its use in a way similar to that of alco-

hol. The State of Vermont also passed the H.511 bill in 2018, which legalized the possession and

limited cultivation of marijuana by adults ages 21 and older as currently enforced in Washington,

1University of Nevada, Las Vegas, USA

Corresponding Author:

Seong-min Park, Department of Criminal Justice, University of Nevada, Las Vegas, 4505 S. Maryland Parkway, Las

Vegas, NV 89154-5009, USA.

Email: seong.park@unlv.edu

912695JODXXX10.1177/0022042620912695Journal of Drug IssuesPark et al.

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