Psychoactive Substance Use Disorders: Drugs. Daughters, S. B.1, Bornovalova, M. A. 1, Correia, C. 2, & Lejuez, C. W. 1University of Maryland 1Auburn University 2 In M. Hersen, S. M. Turner, & D. Beidel Adult psychopathology and diagnosis: Fifth edition. Hoboken, NJ: Wiley.The incidence and prevalence of substance use disorders (SUDs) continues to present major costs to individuals, families, and society at large. It has been estimated that $484 billion is spent each year on substance abuse-related costs including treatment and prevention, health care expenditures, lost wages, reduced job production, accidents, and crime (NIDA, 2004), with over 60% of these costs linked to drug-related incidents. Specifically, over $60 billion is spent on the purchase of drugs annually, with $10 billion on heroin, $35.2 billion on cocaine, $10.5 billion on marijuana, $15 billion on prescription drugs, and $5 billion on other illegal drugs (SAMHSA, 2002). Moreover, in 2001 there were an estimated 638,484 drug-related emergency room episodes and drug-related deaths reached 19,698 in 2000, up from 16,926 just two years before (SAMHSA, 2002). Aside from the troubling public cost statistics, SUDs are associated with engagement in multiple health-compromising behaviors (e.g., condom non-use, multiple partners, impulsive spending) and subsequent physical, social, and emotional consequences (Wallace, 2001). It has become increasingly clear that understanding the development and maintenance of SUDs is a complex problem. Towards this goal, this chapter aims to provide an overview of current practices and cutting edge advancements in the diagnosis, epidemiology, etiology, and assessment of SUDs. As a first step, we provide an overview of the clinical picture of SUD including a review of several diagnostic approaches, epidemiology, comorbidity, course and prognosis, and issues of diversity. Next, we review the etiology of SUD, focusing primarily on biological, genetic, behavioral, and cognitive theories. We then present an up to date review of the assessment options of SUD, including self report, interview, and biological assessment measures for diagnostic, treatment planning, and post treatment assessment purposes. Finally, we present a case study to illustrate the key issues presented in the chapter. It should be noted that to provide a relatively brief review focused on the development and assessment of SUDs, a thorough review of individual drugs and their pharmacological properties and consequences is simply not feasible. Table 1 lists basic information on the most commonly used and abused substances, yet this is not meant to be exhaustive and the interested reader is referred to Julien (2004) for a more thorough treatment of this topic. CLINICAL PICTURE Description and Diagnosis The Diagnostic and Statistical Manual (DSM-IV-TR; American Psychiatric Association, 1994) provides a comprehensive classification system for the assessment and subsequent diagnosis of substance abuse and dependence. The DSM-IV-TR diagnostic criteria for substance abuse require evidence of a maladaptive pattern of substance use with clinically significant levels of impairment or distress. Impairment in this case is defined as an inability to meet major role obligations, leading to reduced functioning in one or more major areas of life, risk-taking behavior, an increase in the likelihood of legal problems due to possession, and exposure to hazardous situations. Within the DSM-IV, substance abuse is treated as a residual category, such that it can only be met without the presence of current substance dependence. The DSM-IV-TR diagnostic criteria for substance dependence specifies a maladaptive pattern of substance use leading to clinically significant impairment or distress as manifested by three (or more) problems occurring at any time in the same 12-month period. These problems include a) taking the substance in larger amounts or over a longer period than intended; b) a persistent desire or unsuccessful efforts to cut down or control substance use; c) spending a great deal of time in activities necessary to obtain (e.g., visiting multiple doctors or driving long distances), use (e.g., chain smoking), or recover (e.g., recovering from a hangover) from the effects of substance use; d) reduction in important social, occupational, or recreational activities; 2e) and continued use despite knowledge of having a persistent or recurrent psychological, or physical problem that is caused or exacerbated by use of the substance. Finally, additional symptoms of dependence are tolerance, defined as either a need for increasing amounts of the substance in order to achieve intoxication or desired effect; or markedly diminished effect with continued use of the same amount, as well as withdrawal (the physiological and mental readjustment that accompanies discontinuation of the use of an addictive substance), which is manifested by physical or psychological symptoms characteristic for a particular substance (APA, 1994). For instance, in the case of heroin, withdrawal symptoms may include flu-like symptoms, as well as nausea, stomach aches, and cramps. In contrast, withdrawal from crack/cocaine usually includes severe but transient dysphoria, nightmares, and fatigue. Interestingly, anecdotal and empirical evidence suggest that when an individual is dependent on two or more drugs (e.g., cocaine and heroin), withdrawal from one drug (heroin) might “mask” the relatively less severe withdrawal from its counterpart (cocaine), suggesting a need for careful screening and questioning in diagnostic interviews. Additional information on the withdrawal symptoms associated with specific drugs is included on Table 1. Another system, the International Classification of Diseases, Tenth Revision (ICD-10, World Health Organization, 1992) is considered the international standard diagnostic classification for all general epidemiological and many health management purposes, including the analysis of the general health situation of population groups and monitoring of the incidence and prevalence of diseases in relation to social, biological, and interpersonal variables. Although the DSM and ICD have very similar definitions of substance dependence, the two systems have had different paradigms for less severe forms of maladaptive substance use which overlap only partially. Consider the example of a diagnosis of substance abuse (in the DSM-IV) and the