Substance use disorders in Iraq and Afghanistan veterans in VA healthcare, 2001–2010: Implications for screening, diagnosis and treatment

Abstract

Background

The prevalence and correlates of alcohol use disorder (AUD) and drug use disorder (DUD) diagnoses in Iraq and Afghanistan veterans who are new users of Department of Veterans Affairs (VA) healthcare nationwide has not been evaluated.

Methods

VA administrative data were used in retrospective cross-sectional descriptive and multivariable analyses to determine the prevalence and independent correlates of AUD and DUD in 456,502 Iraq and Afghanistan veterans who were first-time users of VA healthcare between October 15, 2001 and September 30, 2009 and followed through January 1, 2010.

Results

Over 11% received substance use disorder diagnoses: AUD, DUD or both; 10% received AUD diagnoses, 5% received DUD diagnoses and 3% received both. Male sex, age < 25 years, being never married or divorced, and proxies for greater combat exposure were independently associated with AUD and DUD diagnoses. Of those with AUD, DUD or both diagnoses, 55–75% also received PTSD or depression diagnoses. AUD, DUD or both diagnoses were 3–4.5 times more likely in veterans with PTSD and depression (p < 0.001).

Conclusions

Post-deployment AUD and DUD diagnoses were more prevalent in subgroups of Iraq and Afghanistan veterans and were highly comorbid with PTSD and depression. Stigma and lack of universal screening may have reduced the number of DUD diagnoses reported. There is a need for improved screening and diagnosis of substance use disorders and increased availability of integrated treatments that simultaneously address AUD and DUD in the context of PTSD and other deployment-related mental health disorders.

Introduction

American troops have been deployed to Afghanistan and subsequently to Iraq for nearly a decade. Many soldiers have endured multiple tours of duty and most have experienced combat. Making the transition from warzone to home has been challenging, especially for veterans who have sustained physical injuries, as well as those who have developed mental health problems. Indeed, the prevalence of mental health disorders in veterans of Operation Enduring Freedom (OEF, principally Afghanistan) and Operation Iraqi Freedom (OIF, principally Iraq), particularly posttraumatic stress disorder (PTSD), continues to rise, a trend that has been highlighted in the scientific and popular media (Associated Press, 2008, Friedman, 2010, Milliken et al., 2007, Seal et al., 2009, Tanielian and Jaycox, 2008). In contrast, far less is known about the prevalence and predictors of alcohol use disorders (AUD) and there is only one published report in the medical literature about non-alcohol drug use disorders (DUD) in OEF/OIF military personnel and veterans (Hawkins et al., 2010). Knowledge of the prevalence and correlates of substance use disorders may facilitate early detection and inform targeted interventions to prevent chronic drug and alcohol problems in this current generation of returning veterans.

Recent studies have examined alcohol use in samples of OEF/OIF military service personnel and veterans (Calhoun et al., 2008, Hawkins et al., 2010, Jacobson et al., 2008, McDevitt-Murphy et al., 2010, Santiago et al., 2010, Wilk et al., 2010). In over 48,000 military service personnel participating in the Millennium Cohort Study, Jacobson and colleagues found that National Guard and Reserve personnel were at increased risk for new-onset heavy weekly drinking, binge drinking, and alcohol-related problems, compared to active duty forces (Jacobson et al., 2008). In cross-sectional studies of smaller samples of OEF/OIF veterans in VA healthcare undergoing screening, 22–40% screened positive for high-risk drinking (Calhoun et al., 2008, Erbes et al., 2007, Hawkins et al., 2010, McDevitt-Murphy et al., 2010); 7% of OEF/OIF veterans in a small sample screened positive for cocaine and marijuana use disorders (Hawkins et al., 2010). Thus, while a few studies suggest increased risk for problem drinking and drug use through population screening, to date, there are no national-level studies of the prevalence and correlates of AUD or DUD diagnoses for the entire OEF/OIF veteran population enrolled in VA healthcare in the United States.

Among civilians, up to one-half of those with a substance use disorder (SUD), including alcohol and drug abuse and dependence, also have at least one other comorbid mental health disorder and conversely, about 15–40% of individuals with a mental disorder also abuse substances (Grant et al., 2004, Kessler et al., 1996, Regier et al., 1990). In a large national cohort of Vietnam veterans, 73% of male Vietnam veterans met diagnostic criteria for comorbid PTSD and a lifetime diagnosis of AUD (Kulka et al., 1990). Comorbid SUDs are particularly important to consider in OEF/OIF veterans because of the high rate of co-occurring mental health diagnoses in this population (Seal et al., 2007, Seal et al., 2009). Several studies in both veterans and civilians have supported the prevailing hypothesis that self-medication of mental health symptoms, particularly PTSD symptoms, drives comorbidity with SUD (Bremner et al., 1996, Breslau et al., 2003, Chilcoat and Breslau, 1998). Other evidence however, suggests that SUDs promote the onset of psychiatric disorders and still other data point to shared causal pathways that are genetic or environmental (Kessler, 2004). Of clinical importance, individuals with SUDs that co-occur with other mental disorders often have more severe symptoms, require specialized treatment, and have poorer treatment outcomes (Kessler et al., 1996, Ouimette et al., 1998b, Watkins et al., 2001). Nevertheless, there are no published data on AUD and DUD comorbidity patterns in OEF/OIF veterans that could be used to guide clinical care of these returning veterans.

The Department of Veterans Affairs (VA) healthcare system is the single largest provider of healthcare for OEF/OIF veterans with 565,024 (48%) of the over one million returned combat veterans enrolled (Department of Veterans Affairs, 2010). This study aimed to determine the prevalence and correlates of AUD and DUD diagnoses, including comorbid mental health disorders, in OEF/OIF veterans who were new users of VA healthcare. A better understanding of factors associated with AUD and DUD, including comorbidity patterns, in the large number of veterans returning from war may facilitate targeted screening, secondary prevention, and stimulate more research on integrated treatments for co-occurring substance use and other mental health disorders.