Regulation of drug-maintained behavior: Comment on Meisch (2000).

In his article, R. A. Meisch (see record 2000-00465-009) introduces a concept termed relative persistence of behavior , a measure obtained by comparing rates of behavior under high-response costs to rates obtained under lower response costs. In this commentary, relative persistence of behavior is discussed in terms of behavioral regulation theory, in which responding is allocated in such a way as to maintain a stable balance point. Meisch's relative persistence of behavior may be analogus to the free (paired) baseline technique necessary for testing hypotheses based on behavioral regulation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Quantification of reinforcing effectiveness: Comment on Meisch (2000).

R. A. Meisch (see record 2000-00465-009) introduces an innovative method for quantifying the reinforcing effectiveness of drugs and other substances. Advantages are that it models the persistence of drug use in humans and its persistence ratios are the same whether responding or consumption is measured. Data indicate that the method is sensitive to factors that affect drug self-administration. The measure's core feature is "the systematic variation of both reinforcer magnitude and schedule size" (Meisch, 2000, p. 347); however, the method may not be widely used with such extensive parametric analysis. Variation of only reinforcer magnitude (or dose/concentration) seems to produce similar results, and this abbreviated analysis is similar to the behavioral economic analysis of demand. When responding is plotted as a function of unit price (responses/milligram), the peak of the curve (where maximum responding occurs) is a measure of persistence. Further work will determine how these and other measures of reinforcing effectiveness agree. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of zolpidem and midazolam self-administration under progressive-ratio schedules: Consumer demand and labor supply analyses.

Progressive ratio (PR) schedules of intravenous drug self-administration are useful for establishing the relationships between reinforcing effectiveness and pharmacological actions of abused drugs. The authors compared the reinforcing effects of 2 short-duration benzodiazepine-type drugs differing in their receptor selectivity: zolpidem (selective for gamma aminobutyric acid Type A [GABAA] receptors containing α1 subunits) and midazolam (nonselective). Reinforcing effectiveness was evaluated using a PR schedule of intravenous drug injection in rhesus monkeys in which the response requirement increased across the experimental session and the initial response requirement (IRR) was varied. Analyses based on consumer demand and labor supply models of behavioral economics revealed that the relative reinforcing effectiveness of zolpidem was greater than that of midazolam. For consumer demand analyses, the degree of difference between zolpidem and midazolam depended on whether price was calculated on the basis of different IRRs or different doses of drug. According to labor supply analysis, the reinforcing effects of midazolam were influenced by the economic concept referred to as a price effect to a greater degree than those of zolpidem. These findings suggest that a compound with selectivity for GABAA receptors containing α1 subunits has greater reinforcing effectiveness than a nonselective compound with similar pharmacokinetics, albeit under a limited range of conditions (high response costs). Differences in price effects may play a key role in determining the relative reinforcing effectiveness of selective versus nonselective benzodiazepine agonists. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Heroin purchasing is income and price sensitive.

Semi-structured interviews were used to assess behavioral economic drug demand in heroin dependent research volunteers. Findings on drug price, competing purchases, and past 30-day income and consumption, established in a previous study, are replicated. We extended these findings by having participants indicate whether hypothetical environmental changes would alter heroin purchasing. Participants (n = 109) reported they would significantly (p     

Molecular and cellular basis of addiction

Drug addiction results from adaptations in specific brain neurons caused by repeated exposure to a drug of abuse. These adaptations combine to produce the complex behaviors that define an addicted state. Progress is being made in identifying such time-dependent, drug-induced adaptations and relating them to specific behavioral features of addiction. Current research needs to understand the types of adaptations that underlie the particularly long-lived aspects of addiction, such as drug craving and relapse, and to identify specific genes that contribute to individual differences in vulnerability to addiction. Understanding the molecular and cellular basis of addictive states will lead to major changes in how addiction is viewed and ultimately treated.     

Impulsivity as a mediating mechanism between early-life adversity and addiction: Theoretical comment on Lovic et al. (2011).

Early-life adversity, impulsivity, and dopaminergic function have all been implicated in adult drug addiction. The article by Lovic, Keen, Fletcher, and Fleming in this issue further elucidates this relationship by demonstrating that early-life adversity can increase impulsivity and decrease behavioral flexibility in adulthood. Recent literature suggests that these results are likely due to structural and functional changes in regions such as the orbitofrontal cortex (OFC) and nucleus accumbens (NAc), as well as altered dopamine activity. Impulsivity and behavioral inflexibility can increase susceptibility to addiction, and in turn, chronic substance abuse can impair the neurocircuitry underlying behavioral inhibition. Thus, early-life adversity may act as an entry point into a feed-forward spiral of impulsivity and addiction via the dysfunction of regions such as the OFC, NAc, and mesolimbic dopamine. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

National Institute on Drug Abuse's behavioral research agenda.

Basic behavioral research continues to play an integral role in the National Institute on Drug Abuse's (NIDA's) search for solutions to the complex social and public health problems posed by drug abuse and addiction. Along with NIDA's basic molecular and neuroscience research programs, behavioral research has played an important role in increasing clinician's understanding of the mechanisms and processes that underlie addiction. Much has been learned about the ways in which animals and humans respond to their environment and the role these basic behavioral processes play in drug abuse and other drug-abuse-related phenomena, such as withdrawal, craving, and relapse, but there is still much more to be known. The author discusses how NIDA will continue to build and promote its behavioral research agenda and ensure that behavioral research findings are applied in real-life settings when applicable. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relative reinforcing efficacy of alcohol among college student drinkers.

The construct of relative reinforcing efficacy (RRE) is central to many laboratory and theoretical models of drug abuse, but it has not been widely measured in applied clinical research contexts. The authors used a simulated alcohol purchase task to measure RRE in a sample of 267 college student drinkers. Participants reported their alcohol consumption across a range of prices, and their responses were well-described by a regression equation that has been used to construct demand curves in drug self-administration studies. Several measures of relative reinforcing efficacy were generated, including breakpoint, intensity of demand, elasticity, Pmax (price at which response output is maximized), and Omax (maximum alcohol expenditures). Demand for alcohol was inelastic across the initial range of prices but became elastic as price increased. Students who reported recent heavy drinking reported significantly greater intensity of demand, Omax, and breakpoint. These results provide initial support for the validity of the RRE indices generated with the alcohol purchase task. These results also provide empirical support for programs that attempt to reduce alcohol abuse by eliminating low-cost access to alcohol. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Addiction is a brain disease, and it matters

Scientific advances over the past 20 years have shown that drug addiction is a chronic, relapsing disease that results from the prolonged effects of drugs on the brain. As with many other brain diseases, addiction has embedded behavioral and social-context aspects that are important parts of the disorder itself. Therefore, the most effective treatment approaches will include biological, behavioral, and social-context components. Recognizing addiction as a chronic, relapsing brain disorder characterized by compulsive drug seeking and use can impact society's overall health and social policy strategies and help diminish the health and social costs associated with drug abuse and addiction.     

Reliability and validity of a demand curve measure of alcohol reinforcement.

Recent clinical research suggests that several self-report behavioral economic measures of relative reinforcing efficacy (RRE) may show utility as indices of substance abuse problem severity. The goal of the present study was to evaluate the reliability and validity of the Alcohol Purchase Task (APT), a RRE measure that uses hypothetical choices regarding alcohol purchases at varying prices (demand curves) to generate several indices of alcohol-related reinforcement. Participants were 38 college students who reported recent alcohol consumption. Both the raw alcohol purchase/consumption values and several of the computed reinforcement parameters (intensity & Omax) showed good to excellent 2-week test–retest reliability. Reinforcement parameters derived from both a linear-elasticity (Hursh, Raslear, Bauman, & Black, 1989) and an exponential (Hursh & Silberberg, 2008) demand curve equation were generally less reliable, despite the fact that both equations provided a good fit to participants’ reported consumption data. The APT measures of demand intensity (number of drinks consumed when price = 0), Omax (maximum expenditure), and elasticity (α) were correlated with weekly drinking, alcohol-related problems, and other self-report RRE measures (relative discretionary monetary expenditures toward alcohol and/or relative substance-related activity participation and enjoyment). Demand intensity was uniquely associated with problem drinking in a regression model that controlled for weekly consumption. These results provide support for the reliability and validity of the RRE indices generated with the APT. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The next reinforcer: Comment on Meisch (2000).

The comment herein is a response to R. A. Meisch (see record 2000-00465-009), in which he argues for a new conceptualization of reinforcer effects, vis-à-vis relative persistence. The concept is likely to be quite helpful. It is similar to some applications derived from behavioral economics. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relative persistence of behavior: A reply to comments.

The 5 commentaries (see records 2000-00465-010, 2000-00465-011, 2000-00465-012, 2000-00465-023, 2000-00465-024) address many topics; however, some topics are discussed by more than 1 author. These are the selection of baseline schedules and the relation of the relative persistence of behavior to measures and concepts used in behavioral economics. Other topics include bitonic versus monotonic dose-response functions, data obtained at adjacent schedule values, interval schedules, applications of relative persistence measures, regulation theories, and changes in preference as fixed-ratio size increases. In partial response to a comment regarding the validity of the relative persistence measure, the congruence of results from persistence and preference studies is emphasized. Some of the questions that are raised cannot be answered until future studies are completed, and in some cases, conceptual analysis also will be necessary. Nevertheless, the questions are important in identifying experiments that need to be conducted. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A promising intervention for a daunting problem: Comment on Silverman et al. (2001).

Six features of the report are commented on (K. Silverman et al., see record 2001-14365-002). First, the Therapeutic Workplace intervention described in the report represents a creative and promising new approach to drug abuse treatment. Second, to the author's knowledge, it represents the first intervention that has been shown in a randomized clinical trial to significantly reduce cocaine abuse among pregnant women. Third, the report and study are commendable for their scientific rigor. Fourth, the treatment approach is science-based, integrating concepts and principles from several behavioral science literatures. Fifth, the intervention offers a potentially practical way of extending incentive-based drug abuse treatments to community clinics. Sixth and last, the report has the potential to provoke serious thought and consideration of what more might be done to combat the daunting and related problems of chronic unemployment and drug abuse in our poorer communities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Models of relapse and relapse prevention: A commentary.

The author provides a commentary on a series of articles published on relapse to substance abuse. The following points summarize this commentary: animal and human studies of drug priming effects are limited as an analogue for relapse because they fail to address drug self-administration: relapse is following events (contextual initiating conditions) that indicate reduced access to alternative reinforcers; relapse has multiple determinants including internal cognitive processes that may differentiate between urges and substance use: relapse prevention (RP) can be matched with stages of change in treatment; and RP may be associated with emergent effects over time in substance abuse treatment outcome studies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Regulation of Drug Taking by Sensitization and Habituation.

The authors argue that drug taking is an operant behavior that is reinforced by the drug itself. The effectiveness of a drug as a reinforcer is modulated by sensitization and habituation to the drug as it is consumed. According to this model, drug taking stops when habituation reduces the ability of the drug to reinforce its own consumption. Drug taking resumes when spontaneous recovery restores the effectiveness of the drug as a reinforcer. This parsimonious model provides a framework for understanding many findings in the drug literature, including acute and chronic tolerance, the effect of deprivation on consumption, the contextual specificity of tolerance, polydrug abuse, cross-sensitization between stress and drugs, behavioral sensitization, priming, and reinstatement. Although this model cannot explain all aspects of drug taking (e.g., the effect of cognitive manipulations), it has many implications for understanding and controlling human drug consumption and addiction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The value of nonhuman primates in drug abuse research.

The use of nonhuman primates (NHP) is invaluable for drug abuse research. The laboratory animals most closely related to humans are NHP. The phylogeny, anatomy, physiology, neurochemistry, and behavior of NHP are more similar to humans than other laboratory species. There is now an extensive body of literature documenting the neuroanatomical, neurochemical, and neuropharmacological similarities between NHP and humans and the differences between NHP and other laboratory species in dopamine, norepinephrine, serotonin, opioid, and gamma aminobutyric acid systems. Comprehensive studies comparing pharmacokinetics in humans, monkeys, dogs, and rats have shown that data in monkeys are the most predictive of human pharmacokinetic parameters. The long life span and extended adolescent period for NHP permits intensive, long-term investigations and the use of within-subject experimental designs similar to those used in human laboratory studies. Within-subject designs require fewer subjects than standard between-group designs and permit the careful evaluation of individual differences. NHP have been used extensively in drug abuse research for over 40 years and have provided useful information on the behavioral processes associated with drug abuse and addiction as well as drug abuse liability in humans. This review focuses on important species differences between rodents and NHP and on the value of NHP in bridging the gap between rodents and humans to enhance the ability to generalize preclinical findings to human drug abuse. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Is task persistence related to smoking and substance abuse? The application of learned industriousness theory to addictive behaviors.

R. Eisenberger's (1992) learned industriousness theory states that individuals display differing degrees of persistence depending on their history of reinforcement for persistent, effortful behavior. These differences may influence the development, maintenance, and cessation of addictive behaviors. lndividuals with low persistence may especially be attracted to the immediate reinforcement of drugs. Drug use may constitute further training in low persistence. These individuals may also fail to persist in behaviors needed for cessation. Therefore, substance users should display lower persistence than nonusers. In an initial test of this hypothesis, cigarette smokers (n?=?52) were found to be less persistent than nonsmokers (n?=?57) on 2 behavioral tasks. Moreover, drug and alcohol abuse was inversely related to persistence. If future research supports a role of learned industriousness in addictive behaviors, possible approaches toward prevention and treatment would follow. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Obituary: Herbert J. Freudenberger (1926-1999).

Memorializes Herbert J. Freudenberger, known for his treatment of substance abusers and supervised drug abuse training programs. His work in the free clinics and therapeutic communities led to his original development of the clinical concept of burnout. Burnout has since become a construct applied throughout psychology and incorporated into the public vocabulary. Beyond private practice and his work on addiction, he made professional contributions to the understanding of anxiety and executive stress. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relapse prevention strategies in outpatient substance abuse treatment.

Reviews the use of relapse prevention (RP) strategies in the treatment of substance abuse disorders. The work of G. A. Marlatt and J. R. Gordon (1980, 1985) provided the cognitive-behavioral base of RP models and numerous techniques. Specific protocols for the treatment of alcoholism, cocaine abuse, marijuana abuse, and heroin addiction are described. This body of knowledge has given the drug-free outpatient treatment of substance abuse a clear focus and direction. The techniques used in the RP include 7 groups of strategies: psychoeducation, identification of high-risk situations for relapse, development of coping skills, development of new-life behaviors, increased self-efficacy, dealing with relapse and avoiding the abstinence violation effect, and drug and alcohol monitoring. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Contemporary psychoanalytic theories of substance abuse: A disorder in search of a paradigm.

Reviews the psychoanalytic theories of L. Wurmser, E. J. Khantzian, H. Krystal, and J. McDougall concerning substance abuse. According to Wurmser (see record 1988-15069-001), substance abuse is motivated by a narcissistic crisis, and he advocates traditional psychoanalysis as central to treatment. Khantzian (e.g., Khantzian et al, 1990) views addiction as an attempt to make up for an impaired self-concept. According to Krystal (1978), the basic dilemma of the substance abuser lies in his or her disturbed object relations. McDougall (1989) conceives of addiction within the context of psychosomatic illness and observes that such phenomena can be viewed as a defensive mode of dealing with distress. All 4 theorists focus on drug use as an affect regulator and on drugs as external substitutes for internal functions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)