Background Developing means to identify smokers at high risk for relapse could advance relapse prevention therapy. We hypothesized that functional magnetic resonance imaging (fMRI) reactivity to smoking-related cues, measured prior to a quit attempt, could identify smokers with heightened relapse vulnerability. Methods Twenty-one nicotine-dependent women underwent fMRI prior to quitting smoking, during which smoking-related and neutral images were shown. These smokers also were tested for possible attentional biases to smoking-related words using a computerized emotional Stroop (ES) task previously found to predict relapse. Smokers then made a quit attempt and were grouped based on outcomes (abstinence versus slip: smoking 1 cigarette after attaining abstinence). Pre-quit fMRI and ES measurements in these groups were compared. Results Slip subjects had heightened fMRI reactivity to smoking-related images in brain regions implicated in emotion, interoceptive awareness, and motor planning and execution. Smoking cue-induced insula and dorsal anterior cingulate cortex (dACC) reactivity correlated with an attentional bias to smoking-related words. A discriminant analysis of ES and fMRI data predicted outcomes with 79% accuracy. Additionally, smokers who slipped had decreased fMRI functional connectivity between an insula-containing network and brain regions involved in cognitive control, including the dACC and dorsal lateral prefrontal cortex, possibly reflecting reduced top-down control of smoking-related cue-induced emotions. Conclusions These findings suggest that the insula and dACC are important substrates of smoking relapse vulnerability. The data also suggest that relapse-vulnerable smokers can be identified prior to quit attempts, which could enable personalized treatment, improve tobacco-dependence treatment outcomes, and reduce smoking-related morbidity and mortality.
Rationale-The dopaminergic system, particularly D2-like dopamine receptors, has been strongly implicated in reward processing. Animal studies have emphasized the role of phasic dopamine (DA) signaling in reward-related learning, but these processes remain largely unexplored in humans.Objectives-To evaluate the effect of a single, low dose of a D2/D3 agonist-pramipexole-on reinforcement learning in healthy adults. Based on prior evidence indicating that low doses of DA agonists decrease phasic DA release through autoreceptor stimulation, we hypothesized that 0.5 mg of pramipexole would impair reward learning due to presynaptic mechanisms.Methods-Using a double-blind design, a single 0.5 mg dose of pramipexole or placebo was administered to 32 healthy volunteers, who performed a probabilistic reward task involving a differential reinforcement schedule as well as various control tasks.Results-As hypothesized, response bias toward the more frequently rewarded stimulus was impaired in the pramipexole group, even after adjusting for transient adverse effects. In addition, the pramipexole group showed reaction time and motor speed slowing and increased negative affect; however, when adverse physical side effects were considered, group differences in motor speed and negative affect disappeared.Conclusions-These findings show that a single low dose of pramipexole impaired the acquisition of reward-related behavior in healthy participants, and they are consistent with prior evidence suggesting that phasic DA signaling is required to reinforce actions leading to reward. The potential implications of the present findings to psychiatric conditions, including depression and impulse control disorders related to addiction, are discussed.
The objective of this study was to examine whether there is a benefit of adding bupropion SR to high-dose combination nicotine replacement therapy (NRT) and weekly group cognitive behavioral therapy (CBT) for smoking reduction or cessation in schizophrenia. Fifty-one adult smokers with schizophrenia were randomly assigned to a 12-week trial of bupropion SR 300 mg/d or placebo added to transdermal nicotine patch, nicotine polacrilex gum, and CBT. The treatment goal was smoking cessation. The primary outcome measure was biochemically confirmed 7-day point-prevalence of 50% to 100% smoking reduction at week 12. Secondary outcomes were biochemically confirmed tobacco abstinence and change from baseline in expired air carbon monoxide (CO) and psychiatric symptoms. Subjects on bupropion + NRT had a greater rate of 50% to 100% smoking reduction at weeks 12 (60% vs. 31%; P = 0.036) and 24, a lower expired air CO in the treatment and follow-up periods, (F = 13.8; P < 0.001) and a greater continuous abstinence rate at week 8, before NRT taper, (52% vs. 19%; P = 0.014). However, relapse rates in subjects on bupropion + dual NRT were 31% during NRT taper (weeks 8-12) and 77% at the 12-month follow-up. Abstinence rates did not differ by treatment group at weeks 12 (36% vs. 19%), 24 (20% vs. 8%), or 52 (12% vs. 8%). Because abstinence rates were high during treatment with combination pharmacotherapy and relapse rates were very high during taper and after discontinuation of treatment, study of longer term treatment with combination pharmacotherapy and CBT for sustained abstinence is warranted in those who attain initial abstinence with this intervention.
The objective of this study was to examine the efficacy of bupropion for smoking cessation in patients with schizophrenia. Adults with schizophrenia who smoked more than 10 cigarettes per day and wished to try to quit smoking were recruited from community mental health centers, enrolled in a 12-week group cognitive behavioral therapy intervention, and randomly assigned to receive either bupropion sustained-release 300 mg/d or identical placebo. Fifty-three adults, 25 on bupropion and 28 on placebo, were randomized, completed at least 1 postbaseline assessment and were included in the analysis. The primary outcome measures were 7-day point prevalence abstinence in the week after the quit date (week 4) and at the end of the intervention (week 12). Subjects in the bupropion group were significantly more likely to be abstinent for the week after the quit date (36% [9/25] vs. 7% [2/28], P = 0.016) and at end of the intervention (16% [4/25] vs. 0%, P = 0.043). Subjects in the bupropion group also had a higher rate of 4-week continuous abstinence (weeks 8-12) (16% [4/25] vs. 0%, P = 0.043) and a longer duration of abstinence (4.2 [3.2] weeks vs. 1.8 [0.96] weeks, t = 2.30, P = 0.037). The effect of bupropion did not persist after discontinuation of treatment. Subjects in the bupropion group had no worsening of clinical symptoms and had a trend toward improvement in depressive and negative symptoms. We conclude that bupropion does not worsen clinical symptoms of schizophrenia and is modestly effective for smoking cessation in patients with schizophrenia. The relapse rate is high after treatment discontinuation.
Abundant evidence indicates that the neuronal nicotinic acetylcholine receptor (nAChR) system is integral to regulation of attentional processes and is dysregulated in schizophrenia. Nicotinic agonists may have potential for the treatment of cognitive impairment in this disease. This study investigated the effects of transdermal nicotine on attention in individuals with schizophrenia (n ¼ 28) and healthy controls (n ¼ 32). All participants were nonsmokers in order to eliminate confounding effects of nicotine withdrawal and reinstatement that may occur in the study of smokers. Subjects received 14 mg transdermal nicotine and identical placebo in a randomized, placebocontrolled, crossover design. A cognitive battery was conducted before and 3 h after each patch application. The primary outcome measure was performance on the Continuous Performance Test Identical Pairs (CPT-IP) Version. Nicotine significantly improved the performance on the CPT-IP as measured by hit reaction time, hit reaction time standard deviation and random errors in both groups. In addition, nicotine reduced commission errors on the CPT-IP and improved the performance on a Card Stroop task to a greater extent in those with schizophrenia vs controls. In summary, nicotine improved attentional performance in both groups and was associated with greater improvements in inhibition of impulsive responses in subjects with schizophrenia. These results confirm previous findings that a single dose of nicotine improves attention and suggest that nicotine may specifically improve response inhibition in nonsmokers with schizophrenia.
These findings suggest that a single dose of nicotine enhances response to non-drug-related rewards in the environment, with lasting effects. This effect may contribute to reinforcement of early smoking behavior and development of nicotine dependence.
The findings may suggest that obesity in schizophrenia patients is not solely related to food consumption, but perhaps other effects including medication side effects and reduced physical activity. Education and interventions for the schizophrenia population should focus more on overall lifestyle factors such as physical activity and healthy food choices.
The Behavior and Symptom Identification Scale (BASIS-32) was developed to assess mental health outcomes among patients with severe illness treated on inpatient programs. However, its applicability and utility to those treated in outpatient programs has not been determined. The objective of this study was to assess reliability, validity, and sensitivity to change of the BASIS-32 among mental health consumers treated in outpatient programs. A total of 407 outpatients completed the BASIS-32 and the Short Form Health Status Profile (SF-36) at the beginning of a treatment episode and again 30 to 90 days later. Outpatients reported less difficulty at intake than did inpatients, and the BASIS-32 detected statistically significant changes 30 to 90 days after beginning outpatient treatment. Factor structure and construct validity were partially confirmed on this sample of outpatient consumers. Analyses of data from a wide range of facilities and samples would add to validation efforts and to further refinement of the BASIS-32.
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