Experimental & Clinical Psychopharmacology

Bupropion sustained release treatment decreases craving for video games and cue-induced brain activity in patients with Internet video game addiction.
Bupropion has been used in the treatment of patients with substance dependence based on its weak inhibition of dopamine and norepinephrine reuptake. We hypothesized that 6 weeks of bupropion sustained release (SR) treatment would decrease craving for Internet game play as well as video game cue-induced brain activity in patients with Internet video game addiction (IAG). Eleven subjects who met criteria for IAG, playing StarCraft (>30 hr/week), and eight healthy comparison subjects (HC) who had experience playing StarCraft (
Effects of oral caffeine pretreatment on response to intravenous nicotine and cocaine.
Previous research suggests that under conditions of chronic daily caffeine administration, caffeine increases the effects of nicotine. Little is known about the effects of caffeine pretreatment on response to nicotine under infrequent caffeine administration conditions. The present study examined whether infrequent (not on consecutive days) acute oral caffeine administration alters subject-rated, physiological, and monetary value effects of intravenous nicotine in regular users of caffeine, tobacco, and cocaine. To determine the specificity of effects of caffeine on response to nicotine, the effects of caffeine administration on response to intravenous cocaine (another short-acting stimulant) were also studied. Fourteen (1 woman) volunteers participated in this 3–4 week, double-blind, inpatient study. Volunteers participated in 10 experimental conditions in pseudo-randomized order, in which oral caffeine (250 mg/70 kg) or placebo was administered 1 hr before an intravenous injection, consisting of nicotine (1 or 2 mg/70 kg), cocaine (15 or 30 mg/70 kg), or saline. Infrequent acute caffeine pretreatment attenuated the increase resulting from 2 mg/70 kg nicotine administration on ratings of “rush,” “good effects,” “liking,” “high,” and “drowsy/sleepy.” Caffeine had no significant effect on physiological response to nicotine. Caffeine had no significant effect on subject-rated and physiological response to cocaine, with the exception that caffeine significantly augmented blood pressure response to cocaine. In contrast to the previous research using chronic caffeine maintenance, these data suggest that infrequent acute caffeine administration may attenuate nicotine effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)
Acute effects of intranasal oxytocin on subjective and behavioral responses to social rejection.
The hormone and neuropeptide oxytocin is believed to buffer against social stress and reduce social-threat perception. We employed a widely used ostracism paradigm, Cyberball, to investigate whether oxytocin ameliorated the acute behavioral and affective consequences of social rejection. In a double-blind, randomized, between-subjects design, 74 healthy male and female participants were administered intranasal oxytocin or placebo and subsequently ostracized or included during this virtual ball-tossing game. Ostracized participants reported negative affective and attachment-related reactions, as well as a significant motivational change in increased desire to be involved in the game; these effects were not influenced by oxytocin. Intranasal oxytocin did, however, increase included participants' desire to play again with the same participants, suggesting oxytocin enhanced desire for future social engagement following inclusion. These findings are argued to provide evidence that the effects of oxytocin in promoting social approach behavior may be context specific and sensitive to positive social cues. The results suggest that in an explicitly aversive context, oxytocin does not buffer against the immediate impact of blunt social rejection. (PsycINFO Database Record (c) 2010 APA, all rights reserved)
Development of a simulated drinking game procedure to study risky alcohol use.
The aim of the current study was to initiate and describe the development of a Simulated Drinking Game Procedure (SDGP), a safe, efficient, and alcohol-free laboratory protocol for studying drinking game behavior. Fifty-two undergraduates completed the SDGP in a laboratory session, where participants played singles and/or doubles games of Beer Pong. Water was substituted for alcohol in all of the games. The number of drinks consumed during matches and 20-min play periods were coded during each session, and software was used to estimate the peak blood alcohol concentration (BAC) a participant would achieve if he or she had consumed actual alcohol while participating in the SDGP. Results indicated that participation in Beer Pong can lead to rapid consumption of alcohol and an associated rise in BAC. Results also highlight additional risks for female participants associated with participation in drinking games. The SDGP is a research tool capable of increasing our understanding of drinking games. (PsycINFO Database Record (c) 2010 APA, all rights reserved)
Perception of alcohol intoxication shows acute tolerance while executive functions remain impaired.
Several psychological constructs (e.g., subjective perception of intoxication, visuomotor speed) display acute tolerance to alcohol, that is, show improvement at declining blood alcohol concentrations (BACs) relative to equivalent rising BACs. However, methodological challenges emerge when attempting to make such comparisons across limbs of the BAC curve, which have proven a barrier to advancing research on acute tolerance. To date, no studies have made multiple comparisons across the entire BAC trajectory. This study employs experimental procedures that overcome some of these difficulties, offering a clearer picture of recovery of impairment for subjective perception of intoxication and cognitive performance and the relationship between them. Twenty participants were assessed at multiple time points over 2 days. Continuous subjective perception of intoxication ratings and cognitive data derived from a computerized measure were paired with a novel analytic paradigm, which allowed comparisons at identified BACs. Results showed acute tolerance for individuals' subjective perception of intoxication and for performance on cognitive tasks measuring visuomotor speed and learning efficiency (recovery from impairment). In contrast, performance on measures of executive function and short-term memory showed no significant difference between limbs at exact concentrations (no recovery from impairment). Therefore, despite participants feeling less intoxicated over time, many cognitive functions remained impaired. The implication for these findings in terms of drunken driving behavior are substantial, suggesting that people may be likely to drive once they subjectively perceive that they have recovered from the acute intoxicating effects of alcohol, despite the persistence of “higher order” cognitive impairments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)
Craving and physiological reactivity to trauma and alcohol cues in posttraumatic stress disorder and alcohol dependence.
The high comorbidity of posttraumatic stress disorder (PTSD) and alcohol dependence (AD) has been firmly established. Although laboratory studies have examined self-reported craving in response to trauma and alcohol cues, no studies have reported on alcohol-related physiological responding in response to trauma cues in PTSD-AD individuals. Using a cue reactivity paradigm, this study examined the impact of personalized trauma-image cues and in vivo alcohol cues on alcohol-related responding (e.g., salivation, craving) in individuals with PTSD and AD (n = 40). Participants displayed reactivity to both trauma and alcohol cues when compared to neutral cues, including increased self-reported craving and distress, as well as greater salivation. These findings suggest that through repeated pairings of trauma memories and alcohol consumption, salivation may become classically conditioned to trauma cues. Moreover, the fact that the trauma-alcohol cue combination elicited greater alcohol craving, salivary responding, distress, and arousal than either the trauma-neutral or neutral-alcohol cue combinations suggests that effects of the trauma and alcohol cues were additive in nature. Evidence that AD individuals with PTSD report increased alcohol craving and display greater salivation in response to trauma memories, supplements prior research indicating that PTSD-related negative emotion and trauma-related alcohol craving may play an important role in the maintenance of AD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)
Nicotine's enhancing effects on responding maintained by conditioned reinforcers are reduced by pretreatment with mecamylamine, but not hexamethonium, in rats.
Several studies have indicated that nicotine increases responding maintained by conditioned reinforcers. We assessed the effects of subcutaneous injections of 0.3 mg/kg nicotine and two nicotinic antagonists on responding maintained by conditioned and primary reinforcers and responding during extinction in 8 Long Evans rats. Mecamylamine, a central and peripheral nicotinic antagonist, and hexamethonium, a peripheral nicotinic antagonist, were administered prior to a subset of the experimental sessions. Nicotine selectively increased responding maintained by conditioned reinforcers and mecamylamine, but not hexamethonium, attenuated this effect. These results suggest that nicotine's enhancing effect on responding maintained by conditioned reinforcers is mediated in the central nervous system. (PsycINFO Database Record (c) 2010 APA, all rights reserved)
Repeated administration of pioglitazone attenuates development of hyperalgesia in a rat model of neuropathic pain.
Recent studies indicate the central neuroimmune and neuroinflammation activation play a critical role in the pathological states of pain. Pioglitazone, a potent synthetic agonists of PPARγ, has shown to control neuroinflammation in many nervous system-related disorders. The present study was designed to explore the effects of pioglitazone in treating neuropathic pain and its possible neuroimmune mechanisms in the neuropathic pain using lumbar 5 (L5) spinal nerve transection rat model. L5 spinal nerve transection was done to produce hyperalgesia in rats. Pioglitazone (2.5, 5, and 10 mg/kg) was orally administered daily for 14 days, beginning from 1 hour before nerve transection. Mechanical hyperalgesia was measured using Von-Frey filament tests before and after the surgery. Rats were then sacrificed on day 14 postsurgery. The mRNA of inflammatory cytokines such as tumor necrosis factor (TNF-α), interleukin (IL-1β) and nuclear factor kappa B (NF-κB) activity in brain were detected using reverse transcription-polymerase chain reaction and electrophoretic mobility shift assay. We found that pioglitazone (5 and 10 mg/kg) can markedly attenuate mechanical hyperalgesia produced by nerve transection, most significantly on the 14th day. The elevated TNF-α, IL-1β, and NF-κB in brain were accordingly reduced. Our data could conclude that pioglitazone has ameliorative potential in attenuating the painful state associated with L5 nerve transection, which may further be attributed to inhibiting cerebral proinflammatory cytokines production and NF-κB activation in central nervous system. (PsycINFO Database Record (c) 2010 APA, all rights reserved)
The short of it: Abbreviating the temporal discounting procedure.
A typical temporal discounting procedure determines the present, subjective value (indifference point) of a delayed outcome at 5 to 8 different delays to that outcome. These indifference points are used to determine a single index of discounting called a discounting rate. One concern that remains in the collection of this data is the high number of trials or choices, resulting in participant fatigue or other factors that may affect the validity of the data. In this report, we propose an abbreviated alternative to the more comprehensive and time-consuming discounting procedure. Specifically, we propose that fewer indifference points can be used to determine statistically equivalent discount rates with no loss in data sensitivity. We reanalyzed temporal discounting data obtained with 7 indifference points, and estimated discount rates from all combinations of 2, 3, and 4 of the 7 indifference points. Results indicate that valid and sensitive discounting indices can be obtained with fewer indifference points, and the most appropriate sets of indifference points are highlighted. The proposed abbreviated procedure is likely to be particularly useful when time constraints or participant fatigue is a concern as well as in repeated-measures contexts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)
Psychometric evaluation of a Prescription Stimulant Expectancy Questionnaire.
Expectancies influence the initiation and maintenance of substance use. Given the increasing literature devoted to the rise of prescription stimulant misuse, an examination of expectancy effects associated with prescription stimulant use appears warranted. This study employed a revised version of the Prescription Stimulant Expectancy Questionnaire (PSEQ) and examined its psychometric properties in a nationwide sample of 547 participants. An exploratory factor analysis of the 46-item revised questionnaire (PSEQ–II) identified 4 factors: Cognitive Enhancement, Anxiety and Arousal, Social Enhancement, and Guilt and Dependence. The PSEQ–II successfully discriminated among user groups (i.e., nonusers, recreational users, medical users, recreational/medical users). Recreational/medical users held the strongest positive expectancies and nonusers held the weakest; negative expectancies were held most strongly by nonusers and weakest by medical users. Use of the PSEQ–II and knowledge of prescription stimulant-related expectancies may assist in the prevention and treatment of prescription stimulant misuse. (PsycINFO Database Record (c) 2010 APA, all rights reserved)

Experimental and Clinical Psychopharmacology - Vol 18, Iss 4