The high prevalence of substance use disorders among recent MDMA users compared with other drug users: Implications for intervention

Abstract

Aim

In light of the resurgence in MDMA use and its association with polysubstance use, we investigated the 12-month prevalence of substance use disorders (SUDs) among adult MDMA users to determine whether they are at risk of other drug-related problems that would call for targeted interventions.

Methods

Data were drawn from the 2006 National Survey on Drug Use and Health. Past-year adult drug users were grouped into three mutually exclusive categories: 1) recent MDMA users, who had used the drug within the past year; 2) former MDMA users, who had a history of using this drug but had not done so within the past year; and 3) other drug users, who had never used MDMA. Logistic regression procedures were used to estimate the association between respondents' SUDs and MDMA use while adjusting for their socioeconomic status, mental health, age of first use, and history of polydrug use.

Results

Approximately 14% of adults reported drug use in the past year, and 24% of those past-year drug users reported a history of MDMA use. Recent MDMA users exhibited the highest prevalence of disorders related to alcohol (41%), marijuana (30%), cocaine (10%), pain reliever/opioid (8%), and tranquilizer (3%) use. Adjusted logistic regression analyses revealed that, relative to other drug users, those who had recently used MDMA were twice as likely to meet criteria for marijuana and pain reliever/opioid use disorders. They were also about twice as likely as former MDMA users to meet criteria for marijuana, cocaine, and tranquilizer use disorders.

Conclusions

Seven out of ten recent MDMA users report experiencing an SUD in the past year. Adults who have recently used MDMA should be screened for possible SUDs to ensure early detection and treatment.

Introduction

The use of MDMA (3,4-methylenedioxymethamphetamine; ecstasy) is a growing public health concern due to its increasing use, association with polysubstance use, various health consequences, and potential neurotoxic effects on the human brain (Johnston et al., 2007a, Maxwell, 2005, Parrott, 2006, Parrott, 2007). MDMA's reported associations with polysubstance use, as well as its likely negative effects, have important implications for prevention and treatment. It is, however, uncertain whether MDMA users should be targeted for focused interventions to reduce the adverse consequences of polysubstance use. Little is presently known about the extent to which MDMA users are characterized by a severe pattern of substance abuse and whether early case finding and interventions with this population are warranted. Given the recent increase in MDMA use among adults (Substance Abuse and Mental Health Services Administration [SAMHSA], 2007), better understanding of the prevention and treatment needs of this population is needed.

In the United States, MDMA is commonly known as one of several “club drugs” (e.g., MDMA/ecstasy, methamphetamine, d-lysergic acid diethylamide or LSD, gamma-hydroxybutyrate or GHB, and ketamine) (Wu, Schlenger, & Galvin, 2006). In the 1990s, the drug appeared to be used predominantly by whites and party or club participants (Koesters et al., 2002, Maxwell, 2005), but MDMA use later spread to nonwhite groups (e.g., Hispanics and blacks) and non-club settings (Maxwell, 2005). National surveys of Americans show a significant upsurge in MDMA use during the late 1990s and early 2000s (Johnston et al., 2007b, Substance Abuse and Mental Health Services Administration, 2007). Nationally, rates of MDMA-related mortality and admissions to emergency departments also increased substantially from 1994 to 2001 (Patel et al., 2004, Substance Abuse and Mental Health Services Administration, 2002). Probably due to increased reports of MDMA-related health consequences and mortality, its use had declined since then. However, the 2006 and 2007 Monitoring the Future surveys indicate that MDMA is the only illicit drug currently demonstrating evidence of an increase in use and a concomitant decline in perceptions of associated risks (Johnston et al., 2007a, Johnston et al., 2007b). Similarly, the 2006 National Survey on Drug Use and Health (NSDUH) reports that the number of new past-year MDMA users increased substantially from approximately 642,000 in 2003 to 860,000 in 2006 (SAMHSA, 2007).

Epidemiological studies suggest that MDMA users are also likely to use cigarettes, alcohol, and other drugs (Carlson et al., 2005, Parrott, 2001, Parrott, 2007, Strote et al., 2002, Topp et al., 1999, Wu et al., 2006). The 2002 NSDUH showed that the majority of past-year MDMA users reported a history of use of alcohol (99%), marijuana (98%), prescription opioids (63%), cocaine (57%), and inhalants (45%) (Wu et al., 2006). Another study of a purposive sample of 402 MDMA users recruited from Ohio (Carlson et al., 2005) also reported a high prevalence of use of other substances: alcohol (100%), marijuana (99%), cigarettes (91%), prescription opioids (80%), cocaine (63%), and inhalants (58%). In Australia, similarly high rates of history of polysubstance use have been observed among MDMA users (Topp et al., 1999).

Despite the widely reported concern over polysubstance use by MDMA users and its potential influence on functional deficits and structural changes to the brain (Parrott, 2006, Reneman et al., 2006), the extent of specific current substance use disorders (SUDs) among MDMA users is unknown. Previous studies have focused mainly on substance use per se (e.g., Carlson et al., 2005, Parrott, 2001, Strote et al., 2002, Scholey et al., 2004, Topp et al., 1999, Wu et al., 2006)—a crude measure that provides limited information concerning the intensity and magnitude of problems related to the use of specific substances among MDMA users. As a result, there is limited information concerning whether MDMA users actually constitute a unique group of polysubstance abusers who are distinct from users of other drugs and whether MDMA users may be particularly adversely affected by the concomitant abuse of other substances (Parrott et al., 2007, Gouzoulis-Mayfrank and Daumann, 2006, Parrott, 2006). Such information has important implications for designing appropriate intervention and prevention programs, as well as selecting MDMA users for clinical research.

In this study, we investigate the 12-month prevalence of specific Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV SUDs (American Psychiatric Association, 2000) and their associations with MDMA use within the context of a nationally representative sample of American adults aged 18 years or older. The focus on adults is based on the findings that the vast majority (70%) of new MDMA users are aged 18 years or older (SAMHSA, 2007). We examine past-year measures of SUDs and MDMA use because they are indicators of recent or active use and because the information they provide is highly relevant to the design of early intervention and treatment programs. Additionally, while the onset of drug use prior to adulthood constitutes a risk factor for developing SUDs (Grant & Dawson, 1998), previous studies have not addressed the association between SUDs and the early onset of MDMA use. Thus, we also examine whether MDMA users who initiated use early in life are associated with increased odds of SUDs than drug users who began use later or who have never used MDMAs.

The 2006 NSDUH is the most recent year available and demonstrates the significant upsurge in MDMA use among adults (SAMHSA, 2007). These data provide an excellent means for identifying the characteristics of recent MDMA users and for determining whether MDMA use occurs among casual (e.g., experimental) or more problematic substance users. This data source also constitutes the nation's largest study of drug use, thus providing sufficient statistical power to allow us to control for the potentially confounding effects of prior MDMA use among users of drugs other than MDMA by investigating SUDs across groups stratified by MDMA and other drug use. Because it is representative of domiciled adults in the U.S., this large sample also permits the generalizability of study findings.

We address three main questions. First, what are the sociodemographic and mental health characteristics of past-year MDMA users, and are these characteristics distinct from those of former MDMA users and users of drugs other than MDMA? Second, are there higher prevalence rates of SUDs among past-year MDMA users than among former MDMA users and other drug users? Third, are past-year and early-onset MDMA use still associated with SUDs after statistically controlling potential confounds such as socioeconomic status, mental health, age of first drug use, and history of polydrug usage.