Marcus R Munafò

University of Bristol, Bristol, England, United Kingdom

Are you Marcus R Munafò?

Claim your profile

Publications (310)1817.5 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Plain packaging requires tobacco products to be sold in packs with a standard shape, method of opening and colour, leaving the brand name in a standard font and location. We ran a randomised controlled trial to investigate the impact of plain packaging on smoking behaviour and attitudes. In a parallel group randomised trial design, 128 daily smokers smoked cigarettes from their usual UK brand, or a plain Australian brand that was closely matched to their usual UK brand for 24 hours. Primary outcomes were number of cigarettes smoked and volume of smoke inhaled per cigarette. Secondary outcomes were self-reported ratings of motivation to quit, cigarette taste, experience of using the pack, experience of smoking, attributes of the pack, perceptions of the health warning, changes in smoking behaviour, and views on plain packaging. There was no evidence that pack type had an effect on either of the primary measures (ps > 0.279). However, smokers using plain cigarette packs rated the experience of using the pack more negatively (-0.52, 95% CI -0.82 to -0.22, p = 0.001), rated the pack attributes more negatively (-1.59, 95% CI -1.80 to -1.39, p < 0.001), and rated the health warning as more impactful (+0.51, 95% CI 0.24 to 0.78, p < 0.001). Plain cigarette packs reduce ratings of the experience of using the cigarette pack, and ratings of the pack attributes, and increase the self-perceived impact of the health warning, but do not change smoking behaviour, at least in the short term. Current Controlled Trials ISRCTN52982308 . Registered 27 June 2013.
    BMC Public Health 12/2015; 15(1):1586. DOI:10.1186/s12889-015-1586-8 · 2.32 Impact Factor
  • Source
    04/2015; 2:39-45. DOI:10.1016/j.cobeha.2014.08.002
  • [Show abstract] [Hide abstract]
    ABSTRACT: The serotonin-noradrenaline reuptake inhibitor (SNRI) duloxetine is an effective treatment for major depression and generalised anxiety disorder. Neuropsychological models of antidepressant drug action suggest therapeutic effects might be mediated by the early correction of maladaptive biases in emotion processing, including the recognition of emotional expressions. Sub-chronic administration of duloxetine (for two weeks) produces adaptive changes in neural circuitry implicated in emotion processing; however, its effects on emotional expression recognition are unknown. Forty healthy participants were randomised to receive either 14 days of duloxetine (60 mg/day, titrated from 30 mg after three days) or matched placebo (with sham titration) in a double-blind, between-groups, repeated-measures design. On day 0 and day 14 participants completed a computerised emotional expression recognition task that measured sensitivity to the six primary emotions. Thirty-eight participants (19 per group) completed their course of tablets and were included in the analysis. Results provide evidence that duloxetine, compared to placebo, may reduce the accurate recognition of sadness. Drug effects were driven by changes in participants' ability to correctly detect subtle expressions of sadness, with greater change observed in the placebo relative to the duloxetine group. These effects occurred in the absence of changes in mood. Our preliminary findings require replication, but complement recent evidence that sadness recognition is a therapeutic target in major depression, and a mechanism through which SNRIs could resolve negative biases in emotion processing to achieve therapeutic effects. © The Author(s) 2015.
    Journal of Psychopharmacology 03/2015; DOI:10.1177/0269881115570085 · 2.81 Impact Factor
  • Suzanne H Gage, Marcus R Munafò
    The Lancet Psychiatry 02/2015; DOI:10.1016/S2215-0366(14)00057-1
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: One's peer group can have a strong impact on depressed mood and harmful drinking in adolescence. It remains unclear whether affiliation with deviant peers explains the link between these traits. Our study aims to (1) explore the developmental relationship between harmful drinking and depressed mood in adolescence and (2) establish to which extent affiliation with deviant peers explains this relationship. A total of 4,863 adolescents from the Avon Longitudinal Study of Parents and Children were assessed between the ages of 14 and 16 years. Harmful drinking was established using age-appropriate measures: the Semi-Structured Assessment for the Genetics of Alcoholism in mid-adolescence (age, 14 years) and the Alcohol Use Disorders Identification Test in late adolescence (age, 16 years). Depressed mood was measured by the Short Mood and Feelings Questionnaire at both ages. Affiliation with deviant peers was assessed at the age of 15 years. Harmful drinking at the age of 14 years predicted depressed mood 2 years later. This association was explained by affiliation with deviant peers and remained present even after adjustment for earlier depressed mood. Depressed mood at the age of 14 years predicted harmful drinking at the age of 16 years via affiliation with deviant peers; however, this indirect effect disappeared when adjusting for adolescents' earlier harmful alcohol use (age, 14 years). No gender differences were observed. Adolescents who engage in early harmful drinking and subsequently become affiliated with a deviant peer group may be at particular risk of later depressed mood. Copyright © 2015 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.
    Journal of Adolescent Health 02/2015; 56(2). DOI:10.1016/j.jadohealth.2014.10.268 · 2.75 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Alcohol consumption is known to be associated with risky sexual behaviours, but this relationship may be complex and bidirectional. We explored whether alcohol consumption leads to the consumer being rated as more attractive than sober individuals. Heterosexual social alcohol consumers completed an attractiveness-rating task, in which they were presented with pairs of photographs depicting the same individual, photographed while sober and after having consumed alcohol (either 0.4 or 0.8 g/kg), and required to decide which image was more attractive. Photographs of individuals who had consumed a low dose of alcohol (equivalent to 250 ml of wine at 14% alcohol by volume for a 70 kg individual) were rated as more attractive than photographs of sober individuals. This was not observed for photographs of individuals who had consumed a low dose of alcohol. In addition to perceiving others as more attractive, a mildly intoxicated alcohol consumer may also be perceived as more attractive by others. This in turn may play a role in the relationship between alcohol consumption and risky sexual behaviour. © The Author 2015. Medical Council on Alcohol and Oxford University Press.
    Alcohol and alcoholism (Oxford, Oxfordshire). Supplement 02/2015; DOI:10.1093/alcalc/agv010
  • [Show abstract] [Hide abstract]
    ABSTRACT: Inhalation of 7.5% carbon dioxide increases anxiety and autonomic arousal and provides a novel experimental model of anxiety with which to evaluate pharmacological and psychological treatments for anxiety. To date several psychotropic drugs including benzodiazepines, SSRIs and SNRIs have been evaluated using the 7.5% CO2 model; however, it has yet to be used to evaluate psychological interventions. We compared the effects of two core psychological components of mindfulness-meditation (open monitoring and focused attention) against general relaxation, on subjective, autonomic and neuropsychological outcomes in the 7.5% CO2 experimental model. 32 healthy screened adults were randomized to complete 10 min of guided open monitoring, focused attention or relaxation, immediately before inhaling 7.5% CO2 for 20 min. During CO2-challenge participants completed an eye-tracking measure of attention control and selective attention. Measures of subjective anxiety, blood pressure and heart rate were taken at baseline and immediately following intervention and CO2-challenge. OM and FA practice reduced subjective feelings of anxiety during 20-min inhalation of 7.5% CO2 compared to relaxation control. OM practice produced a strong anxiolytic effect, whereas the effect of FA was more modest. Anxiolytic OM and FA effects occurred in the absence of group differences in autonomic arousal and eye-movement measures of attention. Our findings are consistent with neuropsychological models of mindfulness-meditation that propose OM and FA activate prefrontal mechanisms that support emotion regulation during periods of anxiety and physiological hyper-arousal. Our findings complement those from pharmacological treatment studies, further supporting the use of CO2 challenge to evaluate future therapeutic interventions for anxiety. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Observational studies have shown that attentional bias for smoking-related cues is associated with increased craving and relapse. Laboratory experiments have shown that manipulating attentional bias may change craving. Interventions to reduce attentional bias could reduce relapse in smokers seeking to quit. We report a clinical trial of attentional retraining in treatment-seeking smokers. This was a double-blind randomised controlled trial that took place in UK smoking cessation clinics. Smokers interested in quitting were randomised to five weekly sessions of attentional retraining (N=60) or placebo training (N=58) using a modified visual probe task from one week prior to quit day. Both groups received 21mg nicotine patches (from quit day onwards) and behavioural support. Primary outcomes included change in attentional bias reaction times four weeks after quit day on the visual probe task and craving measured weekly using the Mood and Physical Symptoms Scale. Secondary outcomes were changes in withdrawal symptoms, time to first lapse and prolonged abstinence. No attentional bias towards smoking cues was found in the sample at baseline (mean difference=3ms, 95% CI=-2, 9). Post-training bias was not significantly lower in the retraining group compared with the placebo group (mean difference=-9ms, 95% CI=-20, 2). There was no difference between groups in change in craving (p=0.89) and prolonged abstinence at four weeks (risk ratio=1.00, 95% CI=0.70, 1.43). Taken with one other trial, there appears to be no effect from clinic-based attentional retraining using the visual probe task. Attentional retraining conducted out of clinic may prove more effective. UK Clinical Trials ISRCTN 54375405. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
    Drug and Alcohol Dependence 02/2015; DOI:10.1016/j.drugalcdep.2015.01.041 · 3.28 Impact Factor
  • Jennifer J Ware, Neil M Davies, Marcus R Munafò
    01/2015; 3(2). DOI:10.1016/S2213-2600(14)70319-4
  • Jennifer J Ware, Marcus R Munafò
    [Show abstract] [Hide abstract]
    ABSTRACT: It is now well-established that smoking-related behaviours are under a substantial degree of genetic influence. Efforts are now focused on identifying the specific genetic variants which underlie these behaviours. Within this chapter, we introduce a variety of established and emerging methods employed to identify such variants, ranging from candidate gene to whole genome sequencing approaches, and highlight what these techniques have taught us about the genetic architecture of smoking-related behaviours. Further, we discuss how phenotype refinement has developed our understanding of these relationships, affording us insight into the specific mechanisms linking genetic variants to smoking-related behaviours.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Introduction Rates of obesity are higher among more dependent smokers and 37-65% of smokers seeking cessation treatment are overweight or obese. Overweight or obese smokers may possess metabolic and neurobiological features that contribute to difficulty achieving cessation using front-line nicotine replacement products. Attention to factors that facilitate effective cessation treatment in this vulnerable population is needed to significantly reduce mortality risk among overweight and obese smokers. Method This secondary analysis of two large trials of transdermal nicotine replacement in general medical practices evaluated the hypothesis that higher body mass index (BMI) would moderate the efficacy of the nicotine patch. We examined the potential for gender to further moderate the relationship between BMI and treatment efficacy. Results In the placebo controlled trial (N=1,621), 21 mg patch was no more effective than placebo for assisting biochemically verified point prevalence abstinence up to one-year after quitting for women with higher BMI, but appeared to be effective for men at normal or high BMI (gender x BMI beta = -0.22, p = 0.004). We did not find differential long-term cessation outcomes among male or female smokers in the 15mg patch trial (n=705). However, we observed significantly higher rates of early lapse among women with higher BMI treated with nicotine patch across both trials. Conclusion These results suggest that increased BMI may affect the efficacy of nicotine patch on reducing risk of early lapse in women. Additional research is needed to explore mechanisms of risk for decreased efficacy of this commonly used cessation aid. © The Author 2014. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
    Nicotine & Tobacco Research 12/2014; DOI:10.1093/ntr/ntu256 · 2.81 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: There is a large body of pre-clinical and some clinical data to link the neuropeptide galanin to a range of physiological and pathological functions that include metabolism, depression, and addiction. An enhancer region upstream of the human GAL transcriptional start site has previously been characterised. In-vitro transfection studies in rat hypothalamic neurons demonstrated that the CA allele was 40% less active than the GG allele in driving galanin expression. Our hypothesis was to investigate the effect of this galanin enhancer genotype on a range of variables that relate to the known functions of the galaninergic system in the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort of young adults (N = 169–6,078). Initial findings showed a positive relationship of cannabis usage (OR = 2.070, P = 0.007, N = 406 (individuals who had used cannabis at least once within the last 12 months, total sample size 2731) with the GG haplotype, consistent with the previous published data linking galanin with an increased release of dopamine. As our sample size was relatively small we replicated the analysis in a larger cohort of 2,224 African Americans and 1,840 European Americans, but no discernible trend across genotypes was observed for the relationship with cannabis usage. Further, we found no association of the galanin enhancer genotype with any of the other pathophysiological parameters measured. These findings emphasise that preclinical data does not always predict clinical outcomes in cohort studies, noting that association studies are subject to multiple confounders. © 2014 The Authors. American Journal of Medical Genetics Part B: Neuropsychiatric Genetics published by Wiley Periodicals, Inc.
    American Journal of Medical Genetics Part B Neuropsychiatric Genetics 12/2014; 165(8). DOI:10.1002/ajmg.b.32270 · 3.27 Impact Factor
  • Source
    Marcus R Munafò, Jonathan Flint
    [Show abstract] [Hide abstract]
    ABSTRACT: It is now clear that almost all complex traits have a highly polygenic component; that is, their genetic basis consists of relatively frequent risk alleles at a very large number of loci, each making a small contribution to variation, or disease susceptibility. This general conclusion appears to hold for intermediate phenotypes. Therefore, we should not expect these phenotypes to be associated with substantially larger effect sizes than conventional phenotypes. Instead, their usefulness is likely to lie in understanding the mechanism underpinning associations identified via genome-wide association studies of conventional phenotypes.
    Psychophysiology 12/2014; 51(12):1331-2. DOI:10.1111/psyp.12355 · 3.18 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We previously used a single nucleotide polymorphism (SNP) in the CHRNA5-A3-B4 gene cluster associated with heaviness of smoking within smokers to confirm the causal effect of smoking in reducing body mass index (BMI) in a Mendelian randomisation analysis. While seeking to extend these findings in a larger sample we found that this SNP is associated with 0.74% lower body mass index (BMI) per minor allele in current smokers (95% CI -0.97 to -0.51, P = 2.00×10-10), but also unexpectedly found that it was associated with 0.35% higher BMI in never smokers (95% CI +0.18 to +0.52, P = 6.38×10-5). An interaction test confirmed that these estimates differed from each other (P = 4.95×10-13). This difference in effects suggests the variant influences BMI both via pathways unrelated to smoking, and via the weight-reducing effects of smoking. It would therefore be essentially undetectable in an unstratified genome-wide association study of BMI, given the opposite association with BMI in never and current smokers. This demonstrates that novel associations may be obscured by hidden population sub-structure. Stratification on well-characterized environmental factors known to impact on health outcomes may therefore reveal novel genetic associations.
    PLoS Genetics 12/2014; DOI:10.1371/journal.pgen.1004799 · 8.52 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: AimsTo investigate the relationship between cannabis and tobacco use by age 15 and subsequent educational outcomes.DesignBirth cohort studySettingEnglandParticipantsThe sample was drawn from the Avon Longitudinal Study of Parents and Children; a core sample of 1,155 individuals had complete information on all the variables.MeasurementsMain exposures were cannabis and tobacco use at age 15 assessed in clinic by computer assisted questionnaire and serum cotinine. Main outcomes were performance in standardised assessments at 16 (Key Stage Four, GCSE) in English and mathematics (mean scores), completion of five or more assessments at grade C level or higher and leaving school having achieved no qualifications. Analyses were sequentially adjusted for multiple covariates using a hierarchical approach. Covariates considered were: maternal substance use (ever tobacco or cannabis use, alcohol use above recommended limits) ; life course socio-economic position (family occupational class, maternal education, family income); child sex; month and year of birth; child educational attainment prior to age 11 (Key Stage 2); child substance use (tobacco, alcohol and cannabis) prior to age 15 and child conduct disorder.FindingsIn fully adjusted models both cannabis and tobacco use at age 15 were associated with subsequent adverse educational outcomes. In general the dose response effect seen was consistent across all educational outcomes assessed. Weekly cannabis use was negatively associated with English GCSE results (Grade Point Difference [GPD], −5.93, 95% CI, −8.34, −3.53) and with mathematics GCSE results (GPD, −6.91, 95% CI, −9.92, −3.89). Daily tobacco smoking was negatively associated with English GCSE (GPD, −11.90, 95% CI, −13.47, −10.33) and with mathematics GCSE (GPD, −16.72, 95% CI, −18.57, −14.86). The greatest attenuation of these effects was seen on adjustment for other substance use and conduct disorder. Following adjustment tobacco appeared to have a consistently stronger effect than cannabis.Conclusions Both cannabis and tobacco use in adolescence are strongly associated with subsequent adverse educational outcomes. Given the non-specific patterns of association seen and the attenuation of estimates on adjustment it is possible that these effects arise through non-causal mechanisms, although a causal explanation cannot be discounted. This article is protected by copyright. All rights reserved.
    Addiction 12/2014; 110(4). DOI:10.1111/add.12827 · 4.60 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background Alcohol-related blackouts (ARBs) are reported by ~50% of drinkers. While much is known about the prevalence of ARBs in young adults and their cross-sectional correlates, there are few prospective studies regarding their trajectories over time during mid-adolescence. This paper reports latent trajectory classes of ARBs between age 15 and 19, along with predictors of those patterns.Methods Latent class growth analysis (LCGA) was used to evaluate the pattern of occurrence of ARBs across 4 time points for 1,402 drinking adolescents from the Avon Longitudinal Study of Parents and Children (ALSPAC). Multinomial regression analyses evaluated age-15 demography, substance-related items, externalizing characteristics, and estimated peer substance use as predictors of latent class membership.ResultsARBs were reported at age 15 in 30% and at age 19 in 74% of these subjects. Four latent trajectory classes were identified: Class 1 (5.1%) reported no blackouts; for Class 2 (29.5%), ARBs rapidly increased with age; for Class 3 (44.9%), blackouts slowly increased; and for Class 4 (20.5%), ARBs were consistently reported. Using Class 2 (rapid increasers) as the reference, predictors of class membership included female sex, higher drinking quantities, smoking, externalizing characteristics, and estimated peer substance involvement (pseudo R2 = 0.22).ConclusionsARBs were common and repetitive in these young subjects, and predictors of their trajectories over time involved multiple domains representing diverse characteristics.
    Alcoholism Clinical and Experimental Research 12/2014; DOI:10.1111/acer.12601 · 3.31 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Many studies have explored associations between depression and facial emotion recognition (ER). However, these studies have used various paradigms and multiple stimulus sets, rendering comparisons difficult. Few studies have attempted to determine the magnitude of any effect and whether studies are properly powered to detect it. We conducted a meta-analysis to synthesize the findings across studies on ER in depressed individuals compared to controls.
    Psychological Medicine 11/2014; DOI:10.1017/S0033291714002591 · 5.43 Impact Factor
  • Sally Adams, Angela S Attwood, Marcus R Munafo
    [Show abstract] [Hide abstract]
    ABSTRACT: Nicotine's effects on mood are thought to enhance its addictive potential. However, the mechanisms underlying the effects of nicotine on affect regulation have not been reliably demonstrated in human laboratory studies. We investigated the effects of abstinence (experiment one), and nicotine challenge and expectancy (experiment two) on attentional bias towards facial emotional stimuli differing in emotional valence.
    Nicotine & Tobacco Research 10/2014; DOI:10.1093/ntr/ntu219 · 2.81 Impact Factor
  • Amy E Taylor, George Davey Smith, Marcus R Munafò
    American Journal of Epidemiology 10/2014; 180(9). DOI:10.1093/aje/kwu269 · 4.98 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Smoking-related cues can trigger drug-seeking behaviors, and computer-based interventions that reduce cognitive biases towards such cues may be efficacious and cost-effective cessation aids. In order to optimize such interventions, there needs to be better understanding of the mechanisms underlying the effects of cognitive bias modification (CBM). Here we present a protocol for an investigation of the neural effects of CBM and varenicline in non-quitting daily smokers.
    Trials 10/2014; 15(1):391. DOI:10.1186/1745-6215-15-391 · 2.12 Impact Factor

Publication Stats

8k Citations
1,817.50 Total Impact Points

Institutions

  • 2005–2015
    • University of Bristol
      • School of Experimental Psychology
      Bristol, England, United Kingdom
  • 2001–2013
    • University of Oxford
      • • Department of Psychiatry
      • • Wellcome Trust Centre for Human Genetics
      • • Clinical Genetics Research Group
      Oxford, England, United Kingdom
  • 2011
    • University of Bath
      • Department of Psychology
      Bath, ENG, United Kingdom
    • Cardiff University
      • Department of Psychological Medicine and Neurology
      Cardiff, WLS, United Kingdom
  • 2008–2011
    • University of Cambridge
      • Department of Psychiatry
      Cambridge, ENG, United Kingdom
  • 2007–2011
    • University of Birmingham
      • Department of Primary Care Clinical Sciences
      Birmingham, ENG, United Kingdom
    • Brown University
      Providence, Rhode Island, United States
  • 2001–2003
    • University of Southampton
      Southampton, England, United Kingdom