Delay-discounting among homeless, out-of-treatment, substance-dependent men who have sex with men

Impact of time perspectives on texting intervention to reduce HIV/STI transmission among female sex workers in Tijuana and Ciudad Juarez, Mexico

Text messages may sustain post-counseling gains in behavioral improvements and reduce HIV/STI incidence. However, their effectiveness may depend on the messages' time perspective and characteristics of the individual. We evaluated the impact of time perspective on a text messaging intervention designed to maintain improvements in safer sex practices among drug-using and non-drug-using female sex workers (FSWs) in Tijuana (n = 141) and Cd. Juarez (n = 129), Mexico. FSWs received the efficacious Mujer Segura intervention, and were randomized to receive safer sex maintenance text messages with either a short-term or future-oriented time perspective. The outcome was HIV/STI incidence rate over 6-month follow-up. In Tijuana, combined HIV/STI incidence density was lower among FSWs in the FUTURE group (31.67 per 100 py) compared to women in the SHORT-TERM group (62.40 per 100 py). Conversely, in Cd. Juarez, HIV/STI incidence density was lower (although non-significant) among FSWs in the SHORT-TERM group (19.80 per 100 py) compared to those in the FUTURE group (35.05 per 100 py). These findings suggest that future-oriented text messages may sustain post-counseling improvements in sexual risk behavior among FSWs, but findings may vary by FSWs' characteristics (e.g., drug use), and by region and context.

The Relationship Between Psychological Temporal Perspective and HIV/STI Risk Behaviors Among Male Sex Workers in Mexico City

Men who have sex with men (MSM) face a disproportionate burden of HIV incidence and HIV prevalence, particularly young men who have sex with men. The aim of this article was to analyze the relation between a psychological temporal perspective and HIV/sexually transmitted infection (STI) risk behaviors among male sex workers (MSWs), a potentially highly present-oriented group of MSM. A total sample of 326 MSWs were included and responded to a validated psychological scale: the Zimbardo's Time Perspective Inventory; they also reported how frequently they engaged in protective behaviors against HIV and other STI risks behaviors, including condom use with casual and regular partners, as well as prior HIV testing. We adjusted structural equation models to analyze the relation between a psychological temporal perspective and HIV/STI risk behaviors. We found that orientation toward the past was correlated with decreased condom use with casual partners (β = - 0.18; CI_95% - 0.23, - 0.12). Future orientation was not associated with condom use with casual partners. Regarding condom use with regular partners, past and present orientation were related to lower likelihood of condom use (β = - 0.23; CI_95% - 0.29, - 0.17; β = - 0.11; CI_95% - 0.19, - 0.02), whereas future orientation increased the likelihood of condom use with regular partners (β = 0.40; CI_95% 0.31, 0.50). Time orientation (past, present, or future) did not predict the probability of having an HIV test. The design of HIV/STI prevention programs among vulnerable populations, such as MSM and MSWs, should consider specific time-frame mechanisms that can importantly affect sexual risk behavior decisions.

A Computational Analysis of Aberrant Delay Discounting in Psychiatric Disorders

Impatience for reward is a facet of many psychiatric disorders. We draw attention to a growing literature finding greater discounting of delayed reward, an important aspect of impatience, across a range of psychiatric disorders. We propose these findings are best understood by considering the goals and motivation for discounting future reward. We characterize these as arising from either the opportunity costs of waiting or the uncertainty associated with delayed reward. We link specific instances of higher discounting in psychiatric disorder to heightened subjective estimates of either of these factors. We propose these costs are learned and represented based either on a flexible cognitive model of the world, an accumulation of previous experience, or through evolutionary specification. Any of these can be considered suboptimal for the individual if the resulting behavior results in impairments in personal and social functioning and/or in distress. By considering the neurochemical and neuroanatomical implementation of these processes, we illustrate how this approach can in principle unite social, psychological and biological conceptions of impulsive choice.

Examining Delay Discounting of Condom-Protected Sex Among Men Who Have Sex with Men Using Crowdsourcing Technology

Some men who have sex with men (MSM) have unprotected anal intercourse (UAI) in situations that put them at risk for HIV infection despite having the knowledge and skills to avoid these risks. The present study examined the potential role of delay discounting in sexual HIV risk behavior among MSM. Participants (n = 108) completed the Sexual Discounting Task and a questionnaire regarding UAI and other variables associated with HIV risk (e.g., age, socioeconomic status, substance use, psychiatric problems). MSM discounted the value of condom-protected anal intercourse in a manner that was orderly, hyperbolic, and sensitive to partner characteristics that likely influence realworld decisions about using condoms. Steeper discounting was associated with UAI, and other factors related to sexual HIV risk among MSM, including young age, socioeconomic disadvantage, substance use, sex under the influence of substances, and depression). Delay discounting is likely a critical, but underappreciated facet of HIV risk among MSM.

Behavioral economic decision making and alcohol-related sexual risk behavior

The discipline of behavioral economics integrates principles from psychology and economics to systematically characterize decision-making preferences. Two forms of behavioral economic decision making are of relevance to HIV risk behavior: delay discounting, reflecting preferences for immediate small rewards relative to larger delayed rewards (i.e., immediate gratification), and probability discounting, reflecting preferences for larger probabilistic rewards relative to smaller guaranteed rewards (i.e., risk sensitivity). This study examined questionnaire-based indices of both types of discounting in relation to sexual risk taking in an emergency department sample of hazardous drinkers who engage in risky sexual behavior. More impulsive delay discounting was significantly associated with increased sexual risk-taking during a drinking episode, but not general sexual risk-taking. Probability discounting was not associated with either form of sexual risk-taking. These findings implicate impulsive delay discounting with sexual risk taking during alcohol intoxication and provide further support for applying this approach to HIV risk behavior.

Contingency management voucher redemption as an indicator of delayed gratification

This prospective analysis tested whether frequency of voucher redemptions during a contingency management (CM) substance use intervention was significantly associated with participants' ongoing substance use. Homeless, substance-dependent men who have sex with men (N=131) were randomized into either a "full" or "lite" voucher-based CM intervention. All participants earned vouchers for attendance and participation; participants in the CM-full condition also received vouchers for substance abstinence and enactment of prosocial and/or health-promoting behaviors. Multivariate longitudinal negative binomial regression analyses (n=118) assessed the association between substance use during the intervention and frequency of voucher redemptions. Participants who used methamphetamine (IRR=0.66; 95% CI=0.44-0.99) and/or opiates (IRR=0.60; 95% CI=0.40-0.99) during the intervention exhibited less time between voucher redemptions than individuals who achieved abstinence from these substances. Voucher redemption logs can be cost-effective and unobtrusive tools for measuring study participants' tendency to delay gratification.

Does temporal discounting explain unhealthy behavior? A systematic review and reinforcement learning perspective

The tendency to make unhealthy choices is hypothesized to be related to an individual's temporal discount rate, the theoretical rate at which they devalue delayed rewards. Furthermore, a particular form of temporal discounting, hyperbolic discounting, has been proposed to explain why unhealthy behavior can occur despite healthy intentions. We examine these two hypotheses in turn. We first systematically review studies which investigate whether discount rates can predict unhealthy behavior. These studies reveal that high discount rates for money (and in some instances food or drug rewards) are associated with several unhealthy behaviors and markers of health status, establishing discounting as a promising predictive measure. We secondly examine whether intention-incongruent unhealthy actions are consistent with hyperbolic discounting. We conclude that intention-incongruent actions are often triggered by environmental cues or changes in motivational state, whose effects are not parameterized by hyperbolic discounting. We propose a framework for understanding these state-based effects in terms of the interplay of two distinct reinforcement learning mechanisms: a “model-based” (or goal-directed) system and a “model-free” (or habitual) system. Under this framework, while discounting of delayed health may contribute to the initiation of unhealthy behavior, with repetition, many unhealthy behaviors become habitual; if health goals then change, habitual behavior can still arise in response to environmental cues. We propose that the burgeoning development of computational models of these processes will permit further identification of health decision-making phenotypes.

Changing delay discounting in the light of the competing neurobehavioral decision systems theory: a review

Excessively devaluing delayed reinforcers co-occurs with a wide variety of clinical conditions such as drug dependence, obesity, and excessive gambling. If excessive delay discounting is a trans-disease process that underlies the choice behavior leading to these and other negative health conditions, efforts to change an individual's discount rate are arguably important. Although discount rate is often regarded as a relatively stable trait, descriptions of interventions and environmental manipulations that successfully alter discount rate have begun to appear in the literature. In this review, we compare published examples of procedures that change discount rate and classify them into categories of procedures, including therapeutic interventions, direct manipulation of the executive decision-making system, framing effects, physiological state effects, and acute drug effects. These changes in discount rate are interpreted from the perspective of the competing neurobehavioral decision systems theory, which describes a combination of neurological and behavioral processes that account for delay discounting. We also suggest future directions that researchers could take to identify the mechanistic processes that allow for changes in discount rate and to test whether the competing neurobehavioral decision systems view of delay discounting is correct.

Excessive discounting of delayed reinforcers as a trans-disease process contributing to addiction and other disease-related vulnerabilities: emerging evidence

Delay discounting describes the devaluation of a reinforcer as a function of the delay until its receipt. Although all people discount delayed reinforcers, one consistent finding is that substance-dependent individuals tend to discount delayed reinforcers more rapidly than do healthy controls. Moreover, these higher-than-normal discounting rates have been observed in individuals with other behavioral maladies such as pathological gambling, poor health behavior, and overeating. This suggests that high rates of delay discounting may be a trans-disease process (i.e., a process that occurs across a range of disorders, making findings from one disorder relevant to other disorders). In this paper, we argue that delay discounting is a trans-disease process, undergirded by an imbalance between two competing neurobehavioral decision systems. Implications for our understanding of, and treatment for, this trans-disease process are discussed.