The design and baseline characteristics for the HOPE Consortium Trial to reduce pain and opioid use in hemodialysis.

The HOPE Consortium Trial to Reduce Pain and Opioid Use in Hemodialysis (HOPE Trial) is a multicenter randomized trial addressing chronic pain among patients receiving maintenance hemodialysis for end-stage kidney disease. The trial uses a sequential, multiple assignment design with a randomized component for all participants (Phase 1) and a non-randomized component for a subset of participants (Phase 2). During Phase 1, participants are randomized to Pain Coping Skills Training (PCST), an intervention designed to increase self-efficacy for managing pain, or Usual Care. PCST consists of weekly, live, coach-led cognitive behavioral therapy sessions delivered by video- or tele-conferencing for 12 weeks followed by daily interactive voice response sessions delivered by telephone for an additional 12 weeks. At 24 weeks (Phase 2), participants in both the PCST and Usual Care groups taking prescription opioid medications at an average dose of ≥20 morphine milligram equivalents per day are offered buprenorphine, a partial opioid agonist with a more favorable safety profile than full-agonist opioids. All participants are followed for 36 weeks. The primary outcome is pain interference ascertained, for the primary analysis, at 12 weeks. Secondary outcomes include additional patient-reported measures and clinical outcomes including falls, hospitalizations, and death. Exploratory outcomes include acceptability, tolerability, and efficacy of buprenorphine. The enrollment target of 640 participants was met 27 months after trial initiation. The findings of the trial will inform the management of chronic pain, a common and challenging issue for patients treated with maintenance hemodialysis. NCT04571619.

Behavioral Economic Strategies to Improve Enrollment Rates in Clinical Research: Embedded Recruitment Pilot Trial.

BACKGROUND: Nearly 1 in 3 clinical trials end prematurely due to underenrollment. Strategies to enhance recruitment are often implemented without scientific rigor to evaluate efficacy. Evidence-based, cost-effective behavioral economic strategies designed to influence decision-making may be useful to promote clinical trial enrollment. OBJECTIVE: This study evaluated 2 behavioral economic strategies to improve enrollment and retention rates across 4 clinical trials: information provision (IP) and contingency management (CM; ie, lottery). IP targets descriptive and injunctive norms about participating in research and CM provides participants incentives to reinforce a target behavior. METHODS: A sample of 212 participants was enrolled across 4 clinical trials focused on tobacco use: 2 focused on HIV and 2 focused on neuroimaging. The CM condition included a lottery: for each study visit completed, participants received 5 "draws" from a bowl containing 500 "chips" valued at US $0, US $1, US $5, or US $100. In the IP condition, text messages that targeted injunctive norms about research (eg, "Many find it a rewarding way to advance science and be part of a community") were sent through the Way to Health platform before all study visits. Participants were randomized to 1 of 4 conditions: IP, CM, IP+CM, or standard recruitment (SR). We performed logistic regression, controlling for sex and study, with condition as a between-subject predictor. Outcomes were the percentage of participants who attended a final eligibility visit (primary), met intent-to-treat (ITT) criteria (secondary), and completed the study (secondary). Recruitment was evaluated by the percentage of participants who attended a final eligibility visit, enrollment by ITT status, and retention by the percentage of participants who completed the study. RESULTS: Rates of attending the eligibility visit and meeting ITT status were 58.9% (33/56) and 33.9% (19/56) for IP+CM; 45.5% (25/55) and 18.2% (10/55) for IP only; 41.5% (22/53) and 18.9% (10/53) for CM only; and 37.5% (18/48) and 12.5% (6/48) for SR, respectively. In the logistic regression, females were more likely to meet ITT status than males (odds ratio [OR] 2.7, 95% CI 1.2-5.7; P=.01). The IP+CM group was twice as likely to attend the final eligibility visit than the SR group (OR 2.4, 95% CI 1.1-5.2; P=.04). The IP+CM group was also significantly more likely to reach ITT status than the SR condition (OR 3.9, 95% CI 1.3-11.1; P=.01). Those who received any active intervention (IP, CM, or IP+CM) had a higher study completion rate (33/53, 63.5%) compared to those who received SR (5/12, 41.7%), but this difference was not significant (P=.26). CONCLUSIONS: Combining IP and CM strategies may motivate participants to participate in research and improve recruitment and retention rates. Evidence from this study provides preliminary support for the utility of behavioral economics strategies to improve enrollment and reduce attrition in clinical trials.

Brain Marker Links Stress and Nicotine Abstinence.

BACKGROUND: Subjective stress is a well-documented predictor of early smoking relapse, yet our understanding of stress and tobacco use is limited by reliance on self-reported measures of stress. We utilized a validated functional neuroimaging paradigm to examine whether stress exposure during early abstinence alters objective measures of brain function. METHODS: Seventy-five participants underwent blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) during the Montreal Imaging Stress Task (MIST) on two occasions: once during smoking satiety and once following biochemically confirmed 24-hour abstinence (order counterbalanced). The primary outcome measure was brain response during stress (vs. control) blocks of the MIST, assessed using whole-brain analysis corrected for multiple comparisons using clusters determined by Z ≥ 3.1. RESULTS: Abstinence (vs. satiety) was associated with significantly increased activation in the left inferior frontal gyrus, a brain region associated with inhibitory control. Abstinence-induced change in brain response to stress was positively associated with change in self-reported stress. CONCLUSIONS: This study provides objective evidence that the brain response to stress is altered during the first 24 hours of a quit attempt compared to smoking satiety. IMPLICATIONS: These results point to the potential value of inoculating smokers with stress management training prior to a quit attempt.

Neural cue reactivity during acute abstinence predicts short-term smoking relapse.

In smokers, neural responses to smoking cues can be sensitive to acute abstinence, but the degree to which abstinence-related cue reactivity contributes to relapse is not fully understood. This study addressed this question in a sample of 75 smokers who were motivated to quit smoking. Participants underwent blood-oxygen-level-dependent (BOLD) functional magnetic resonance imaging (fMRI) during presentation of visual smoking cues and neutral stimuli on two occasions: once during smoking satiety and once following 24-hour abstinence (order counterbalanced). Following the imaging sessions, participants received brief smoking cessation counseling prior to a short-term (7-day) quit attempt. The primary smoking cessation outcome was biochemically confirmed 7-day relapse. The secondary smoking cessation outcome measure was total number of self-reported days of abstinence. During abstinence (vs satiety), smoking cue reactivity was significantly increased only in the anterior cingulate cortex (ACC); other regions showing a cue (vs neutral) response did not exhibit an abstinence effect in the stringent whole-brain analysis. Participants who showed greater smoking cue reactivity in the ACC during acute abstinence (compared with smoking satiety) were more likely to relapse (OR = 2.10 per standard deviation increase in percent signal change [abstinence minus smoking satiety], 95% CI: 1.05 to 4.20, P = 0.036). Greater abstinence-induced change in ACC activation also predicted fewer total days abstinent (ß = -0.63, 95% CI = 0.43 to 0.66, P < 0.0001). This study provides the first evidence that changes in smoking cue reactivity in the ACC during acute abstinence predict smoking relapse, thereby improving our understanding of the neurobiology of smoking cessation.

Lack of effect of transcranial direct current stimulation (tDCS) on short-term smoking cessation: Results of a randomized, sham-controlled clinical trial.

BACKGROUND: Transcranial direct current stimulation (tDCS) has been shown to improve measures of executive cognitive function and reduce cigarette consumption. Studies conducted to date have been small, and the results are mixed. METHODS: This randomized, double-blind, parallel arm clinical trial tested the effects of active anodal tDCS targeted to the left dorsolateral prefrontal cortex (versus sham) on 7-day smoking cessation in 106 treatment-seeking smokers. Participants received three sessions of sham (n = 35), 1 mA (n = 35), or 2 mA (n = 36) tDCS in the context of a validated smoking lapse paradigm then received brief smoking cessation counseling and completed a monitored quit attempt. The primary outcome was total number of days of abstinence confirmed via exhaled carbon monoxide. RESULTS: During the quit period, there were no effects of dose group on days of abstinence (sham, M (SD): 2.5 days (±2.5); 1 mA: 2.5 days (±2.5); 2 mA: 2.4 days (±2.3); ß = -0.08; p = 0.76) or on change in daily smoking rate (sham, M (SD): 12.6 CPD (±4.8); 1 mA: -11.8 CPD (±4.4); 2 mA: -11.7 CPD (±5.3); ß = 0.42, p = 0.49), nor were there effects of dose group on latency to smoke or number of cigarettes smoked during the smoking lapse paradigm. Side effects of tDCS were generally mild (<5 out of 10), and participants were not able to distinguish between active and sham treatment. CONCLUSIONS: These results do not support the efficacy of tDCS targeted to the left dorsolateral prefrontal cortex (DLPFC) for smoking cessation.

Transcranial direct current brain stimulation decreases impulsivity in ADHD.

BACKGROUND: Impulsivity is a core deficit in attention deficit hyperactivity disorder (ADHD). Transcranial direct current stimulation (tDCS) of the dorsolateral prefrontal cortex (DLPFC) has been shown to modulate cognitive control circuits and could enhance DLPFC activity, leading to improved impulse control in ADHD. OBJECTIVE: Hypothesis: We predicted 2.0 mA anodal stimulation (tDCS) versus sham stimulation applied over the left DLPFC would improve Conners Continuous Performance Task (CPT) scores. Our secondary hypothesis predicted that stop signal task (SST) reaction time (SSRT) would decrease with tDCS (versus sham). METHODS: Thirty-seven participants completed two periods of three tDCS (or sham) sessions two weeks apart in a within-subject, double-blind, counterbalanced order. Participants performed a fractal N-back training task concurrent with tDCS (or sham) stimulation. Participants completed the CPT and SST at the beginning of treatment (baseline), at the end of the treatment, and at a 3-day post-stimulation follow-up. RESULTS: There was a significant stimulation condition by session interaction for CPT false positive scores (χ2 = 15.44, p < 0.001) driven by a decrease in false positive errors from baseline to end of treatment in the tDCS group (ß = -0.36, 95% Confidence Interval (CI) -0.54 to -0.18, p < 0.001). This effect did not persist at follow-up (ß = -0.13, p > 0.05). There was no significant stimulation condition by session interaction effect on CPT true positive errors or response time (ps > 0.05). No significant change in SSRT performance was observed (p > 0.05). CONCLUSION: These findings suggest that stimulation of the left DLPFC with tDCS can improve impulsivity symptoms in ADHD, supporting the therapeutic potential for tDCS in adult ADHD patients.

No Effect of Commercial Cognitive Training on Brain Activity, Choice Behavior, or Cognitive Performance.

Increased preference for immediate over delayed rewards and for risky over certain rewards has been associated with unhealthy behavioral choices. Motivated by evidence that enhanced cognitive control can shift choice behavior away from immediate and risky rewards, we tested whether training executive cognitive function could influence choice behavior and brain responses. In this randomized controlled trial, 128 young adults (71 male, 57 female) participated in 10 weeks of training with either a commercial web-based cognitive training program or web-based video games that do not specifically target executive function or adapt the level of difficulty throughout training. Pretraining and post-training, participants completed cognitive assessments and functional magnetic resonance imaging during performance of the following validated decision-making tasks: delay discounting (choices between smaller rewards now vs larger rewards in the future) and risk sensitivity (choices between larger riskier rewards vs smaller certain rewards). Contrary to our hypothesis, we found no evidence that cognitive training influences neural activity during decision-making; nor did we find effects of cognitive training on measures of delay discounting or risk sensitivity. Participants in the commercial training condition improved with practice on the specific tasks they performed during training, but participants in both conditions showed similar improvement on standardized cognitive measures over time. Moreover, the degree of improvement was comparable to that observed in individuals who were reassessed without any training whatsoever. Commercial adaptive cognitive training appears to have no benefits in healthy young adults above those of standard video games for measures of brain activity, choice behavior, or cognitive performance.SIGNIFICANCE STATEMENT Engagement of neural regions and circuits important in executive cognitive function can bias behavioral choices away from immediate rewards. Activity in these regions may be enhanced through adaptive cognitive training. Commercial brain training programs claim to improve a broad range of mental processes; however, evidence for transfer beyond trained tasks is mixed. We undertook the first randomized controlled trial of the effects of commercial adaptive cognitive training (Lumosity) on neural activity and decision-making in young adults (N = 128) compared with an active control (playing on-line video games). We found no evidence for relative benefits of cognitive training with respect to changes in decision-making behavior or brain response, or for cognitive task performance beyond those specifically trained.

Nicotine withdrawal alters neural responses to psychosocial stress.

INTRODUCTION: Psychosocial stress is considered to be an important mechanism underlying smoking behavior and relapse. Thus, understanding the effects of acute nicotine withdrawal on responses to stress is important to intervene to prevent stress-induced relapse. The current study investigated the neural correlates of psychosocial stress during acute nicotine withdrawal in chronic smokers. METHODS: Thirty-nine treatment-seeking smokers were randomized to one of two conditions (abstinent 24 h (n = 21) or smoking as usual (n = 18)). They were then exposed to the Montreal Imaging Stress Task (MIST), a psychosocial stress task consisting of difficult mental arithmetic problems while receiving negative performance feedback while undergoing functional magnetic resonance imaging (fMRI). RESULTS: Subjective measures of stress increased following the MIST, compared to baseline. Whole brain between-group analysis identified significant activation clusters in four regions for the stress induction minus control contrast: inferior frontal gyrus (IFG), anterior/para cingulate cortex (ACC), precuneus, and supramarginal gyrus (SMG). In all regions, the deprived group showed significantly greater activation compared to the non-deprived group. No significant correlations were found between subjective stress and BOLD signal activation (ps > 0.07). CONCLUSIONS: This study provides new evidence that brain regions previously shown to be predictive of relapse, such as the precuneus and IFG, display heightened neural responses to stress during nicotine deprivation. These data identify the brain regions that may be associated with withdrawal-related stress responses. Increased stress-related activation during nicotine withdrawal may identify those most vulnerable to relapse and represent a target for novel pharmacological intervention.

Brain Responses to Smoking Cues Differ Based on Nicotine Metabolism Rate.

BACKGROUND: Inherited differences in the rate of metabolism of nicotine, the addictive chemical in tobacco, affect smoking behavior and quitting success. The nicotine metabolite ratio (3'-hydroxycotinine/cotinine) is a reliable measure of nicotine clearance and a well-validated predictive biomarker of response to pharmacotherapy. To clarify the mechanisms underlying these associations, we investigated the neural responses to smoking cues in normal and slow nicotine metabolizers. METHODS: Treatment-seeking smokers (N = 69; 30 slow metabolizers and 39 normal metabolizers) completed a visual cue reactivity task during functional magnetic resonance imaging on two separate occasions: once during smoking satiety and once after 24 hours of smoking abstinence. RESULTS: In whole-brain analysis, normal (compared with slow) metabolizers exhibited heightened abstinence-induced neural responses to smoking cues in the left caudate, left inferior frontal gyrus, and left frontal pole. These effects were more pronounced when extreme groups of slow and normal metabolizers were examined. Greater activation in the left caudate and left frontal pole was associated with abstinence-induced subjective cravings to smoke. CONCLUSIONS: Inherited differences in rate of nicotine elimination may drive neural responses to smoking cues during early abstinence, providing a plausible mechanism to explain differences in smoking behaviors and response to cessation treatment. Normal metabolizers may benefit from adjunctive behavioral smoking cessation treatments, such as cue exposure therapy.

Transcranial Direct Current Brain Stimulation Increases Ability to Resist Smoking.

BACKGROUND: The ability to exert self-control over temptation is a fundamental component of smoking behavior change. Transcranial direct current stimulation (tDCS) of the dorsolateral prefrontal cortex (DLPFC) has been shown to modulate cognitive control circuits. Although prior studies show that stimulation reduces cigarette craving and self-reported smoking, effects on ability to resist smoking have not been investigated directly. OBJECTIVES: We assessed effects of a single 20-minute session of 1.0 mA anodal stimulation over the left DLPFC with cathodal stimulation over the right supra-orbital area (vs. sham stimulation) on ability to resist smoking in a validated smoking lapse paradigm. METHODS: Twenty-five participants completed two tDCS sessions (active and sham stimulation) in a within-subject, double-blind, randomized and counterbalanced order with a 2-week washout period. Following overnight abstinence, participants received tDCS in the presence of smoking related cues; they had the option to smoke at any time or receive $1 for every 5 minutes they abstained. After 50 minutes, they participated in a 1 hour ad libitum smoking session. Primary and secondary outcomes were time to first cigarette and cigarette consumption, respectively. RESULTS: In multiple regression models, active tDCS (compared to sham) significantly increased latency to smoke (p = 0.02) and decreased the total number of cigarettes smoked (p = 0.014) during the session. CONCLUSION: These findings suggest that acute anodal stimulation over the left DLPFC (with cathodal stimulation over the right supra-orbital area) can improve ability to resist smoking, supporting the therapeutic potential of tDCS for smoking cessation treatment.