Marcus R Munafò

University of Bristol, Bristol, England, United Kingdom

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Publications (298)1602.51 Total impact

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    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 · 2.26 Impact Factor
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    Meg E Fluharty · Angela S Attwood · Marcus R Munafo ·
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    ABSTRACT: The 7.5% carbon dioxide (CO2) inhalation model is used to provoke acute anxiety, for example to investigate the effects of anxiety on cognitive processes, or the efficacy of novel anxiolytic agents. However, little is known about the relationship of baseline anxiety sensitivity or trait anxiety (i.e., anxiety proneness), with an individual’s response to the 7.5% CO2 challenge. We examined data from a number of 7.5% CO2 challenge studies to determine whether anxiety proneness was related to subjective or physiological response. Our findings indicate anxiety proneness is associated with greater subjective and physiological responses. However, anxiety-prone individuals also have a greater subjective response to the placebo (medical air) condition. This suggests that anxiety-prone individuals not only respond more strongly to the 7.5% CO2 challenge, but also to medical air. Implications for the design and conduct of 7.5% CO2 challenge studies are discussed.
    Journal of Psychopharmacology 11/2015; DOI:10.1177/0269881115615105 · 3.59 Impact Factor
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    ABSTRACT: Introduction: Smoking is a major avoidable cause of ill-health and premature death. Treatments that help patients successfully quit smoking have an important effect on health and life expectancy. Varenicline is a medication that can help smokers successfully quit smoking. However, there are concerns that it may cause adverse effects, such as increase in the occurrence of depression, self-harm and suicide and cardiovascular disease. In this study we aim to examine the effects of varenicline versus other smoking cessation pharmacotherapies on smoking cessation, health service use, all-cause and cause-specific mortality and physical and mental health conditions. Methods: In this project we will investigate the effects of varenicline compared to nicotine replacement therapies on: (1) long-term smoking cessation and whether these effects differ by area level deprivation; and (2) the following clinically-important outcomes: rate of general practice and hospital attendance; all-cause mortality and death due to diseases of the respiratory system and cardiovascular disease; and a primary care diagnosis of respiratory illness, myocardial infarction or depression and anxiety. The study is based on a cohort of patients prescribed these smoking cessation medications from the Clinical Practice Research Datalink (CPRD). We will use three methods to overcome confounding: multivariable adjusted Cox regression, propensity score matched Cox regression, and instrumental variable regression. The total expected sample size for analysis will be at least 180 000. Follow-up will end with the earliest of either an 'event' or censoring due to the end of registration or death. Ethics and dissemination: Ethics approval was not required for this study. This project has been approved by the CPRD's Independent Scientific Advisory Committee (ISAC). We will disseminate our findings via publications in international peer-reviewed journals and presentations at international conferences.
    BMJ Open 11/2015; 5(11):e009665. DOI:10.1136/bmjopen-2015-009665 · 2.27 Impact Factor
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    ABSTRACT: Background: -Smoking is an important cardiovascular disease risk factor, but the mechanisms linking smoking to blood pressure are poorly understood. Methods and results: -Data on 141,317 participants (62,666 never, 40,669 former, 37,982 current smokers) from 23 population-based studies were included in observational and Mendelian randomisation (MR) meta-analyses of the associations of smoking status and smoking heaviness with systolic and diastolic blood pressure (SBP, DBP), hypertension, and resting heart rate. For the MR analyses, a genetic variant rs16969968/rs1051730 was used as a proxy for smoking heaviness in current smokers. In observational analyses, current as compared with never smoking was associated with lower SBP, DBP, and lower hypertension risk, but with higher resting heart rate. In observational analyses amongst current smokers, one cigarette/day higher level of smoking heaviness was associated with higher (0.21 beats/minute; 95% CI 0.19; 0.24) resting heart rate, and slightly higher DBP (0.05 mmHg; 95% CI 0.02; 0.08) and SBP (0.08 mmHg; 95% CI 0.03; 0.13). However, in MR analyses amongst current smokers, while each smoking increasing allele of rs16969968/rs1051730 was associated with higher resting heart rate (0.36 beats/minute/allele; 95% CI 0.18; 0.54), there was no strong association with DBP, SBP, or hypertension. This would suggest a 7 beats/minute higher heart rate in those who smoke 20 cigarettes/day. Conclusions: -This MR meta-analysis supports a causal association of smoking heaviness with higher level of resting heart rate, but not with blood pressure. These findings suggest that part of the cardiovascular risk of smoking may operate through increasing resting heart rate.
    Circulation Cardiovascular Genetics 11/2015; DOI:10.1161/CIRCGENETICS.115.001225 · 4.60 Impact Factor
  • Sarah Griffiths · Chris Jarrold · Ian S. Penton-Voak · Marcus R. Munafò ·
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    ABSTRACT: Many psychological disorders are characterised by insensitivities or biases in the processing of subtle facial expressions of emotion. Training using expression morph sequences which vary the intensity of expressions may be able to address such deficits. In the current study participants were shown expressions from either happy or fearful intensity morph sequences, and trained to detect the target emotion (e.g., happy in the happy sequence) as being present in low intensity expressions. Training transfer was tested using a six alternative forced choice emotion labelling task with varying intensity expressions, which participants completed before and after training. Training increased false alarms for the target emotion in the transfer task. Hit rate for the target emotion did not increase once adjustment was made for the increase in false alarms. This suggests that training causes a bias for detecting the target emotion which generalises outside of the training task. However it does not increase accuracy for detecting the target emotion. The results are discussed in terms of the training’s utility in addressing different types of emotion processing deficits in psychological disorders.
    Psychiatry Research 11/2015; DOI:10.1016/j.psychres.2015.11.007 · 2.47 Impact Factor
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    Dataset: Supplem
    M N Dalili · I S Penton-Voak · C J Harmer · M R Munafò ·

  • Marcus R Munafò ·
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    ABSTRACT: Open access;open data;open science;pre-registration;reproducibility
    Addiction 10/2015; DOI:10.1111/add.13147 · 4.74 Impact Factor
  • Suzanne H Gage · Marcus R Munafò · George Davey Smith ·
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    ABSTRACT: Studies of the developmental origins of health and disease (DOHaD) often rely on prospective observational data, from which associations between developmental exposures and outcomes in later life can be identified. Typically, conventional statistical methods are used in an attempt to mitigate problems inherent in observational data, such as confounding and reverse causality, but these have serious limitations. In this review, we discuss a variety of methods that are increasingly being used in observational epidemiological studies to help strengthen causal inference. These methods include negative controls, cross-contextual designs, instrumental variables (including Mendelian randomization), family-based studies, and natural experiments. Applications within the DOHaD framework, and in relation to behavioral, psychiatric, and psychological domains, are considered, and the considerable potential for expanding the use of these methods is outlined. Expected final online publication date for the Annual Review of Psychology Volume 67 is January 03, 2016. Please see for revised estimates.
    Annual Review of Psychology 10/2015; 67(1). DOI:10.1146/annurev-psych-122414-033352 · 21.81 Impact Factor
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    ABSTRACT: The mu1 opioid receptor gene, OPRM1, has long been a high-priority candidate for human genetic studies of addiction. Because of its potential functional significance, the non-synonymous variant rs1799971 (A118G, Asn40Asp) in OPRM1 has been extensively studied, yet its role in addiction has remained unclear, with conflicting association findings. To resolve the question of what effect, if any, rs1799971 has on substance dependence risk, we conducted collaborative meta-analyses of 25 datasets with over 28,000 European-ancestry subjects. We investigated non-specific risk for "general" substance dependence, comparing cases dependent on any substance to controls who were non-dependent on all assessed substances. We also examined five specific substance dependence diagnoses: DSM-IV alcohol, opioid, cannabis, and cocaine dependence, and nicotine dependence defined by the proxy of heavy/light smoking (cigarettes-per-day >20 vs. ≤10). The G allele showed a modest protective effect on general substance dependence (OR = 0.90, 95 % C.I. [0.83-0.97], p value = 0.0095, N = 16,908). We observed similar effects for each individual substance, although these were not statistically significant, likely because of reduced sample sizes. We conclude that rs1799971 contributes to mechanisms of addiction liability that are shared across different addictive substances. This project highlights the benefits of examining addictive behaviors collectively and the power of collaborative data sharing and meta-analyses.
    Behavior Genetics 09/2015; DOI:10.1007/s10519-015-9737-3 · 3.21 Impact Factor

  • 09/2015; 3(12). DOI:10.1016/S2213-8587(15)00341-1

  • The Lancet Psychiatry 09/2015; 2(5). DOI:10.1016/S2215-0366(15)00108-X
  • AE Taylor · SH Gage · MR Munafo ·
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    ABSTRACT: Background Previous reports suggest that offspring of mothers who smoke during pregnancy have greater risk of developing depression in adolescence. However, it is unclear whether this association is due to intrauterine effects or to confounding by environmental or genetic factors. Using partner smoking during pregnancy as a negative control exposure for maternal smoking during pregnancy can help to strengthen causal inference. If maternal smoking influences offspring depression via intrauterine effects, this should be more strongly associated with offspring depression than partner smoking. Methods We compared the associations of maternal and partner smoking during pregnancy with offspring depression in a UK longitudinal birth cohort, the Avon Longitudinal Study of Parents and Children. Maternal smoking during pregnancy was assessed by self-report in questionnaires administered at two times during pregnancy and once post birth. Partner smoking was assessed by both maternal reports and by self-report in questionnaires administered twice during pregnancy. Smoking during pregnancy was defined as any report of smoking at any time during pregnancy. Offspring depression was measured at age 18 years using the Computerised Interview Schedule-Revised (CIS-R), according to ICD-10 criteria. Analyses were conducted using logistic regression, adjusting for offspring age and sex, maternal age, parity, social class, maternal education, maternal depression, housing tenure and crowding and offspring smoking. Results Of the 15,455 pregnant women enrolled into the study, full data for analysis was available for 3,100 women and their offspring, representing 68% of the 4,564 offspring who completed the CIS-R at age 18. In adjusted analyses, there was weak evidence that maternal smoking during pregnancy was associated with higher odds of offspring depression (OR 1.44, 95% CI: 0.99, 2.07), but no clear evidence that partner smoking was associated with offspring depression (OR 0.87, 95% CI: 0.63, 1.20). There was some statistical evidence that the estimate for maternal smoking differed from that of partner smoking (p = 0.04). Compared to offspring with neither mother or mother’s partner smoking during pregnancy, odds ratios for depression were 0.90 (95% CI: 0.61, 1.32), 1.79 (95% CI: 1.06, 3.01) and 1.70 (95% CI: 1.14, 2.52) for offspring with only their mother’s partners smoking during pregnancy, only their mothers smoking during pregnancy and both mothers and mother’s partners smoking during pregnancy respectively. Conclusion Maternal smoking during pregnancy was more strongly associated with offspring depression at age 18 years than partner smoking, although evidence for the association with maternal smoking was not strong after adjustment for confounders. This is consistent with a possible intrauterine effect of smoking on offspring depression.
    Journal of Epidemiology &amp Community Health 09/2015; 69(Suppl 1). DOI:10.1136/jech-2015-206256.53 · 3.50 Impact Factor
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    ABSTRACT: Possession of the ε4 allele of the Apolipoprotein E (APOE) gene is associated with an increased risk of Alzheimer's disease. Early adult life effects of ε4 are less well understood. Working memory has been relatively little studied (compared to episodic memory) in relation to APOE genotype despite its importance in cognitive functioning. Our hypothesis was that ε4 would lead to an impairment in working memory in young adults. We studied working memory using a computerised n-back task in the Avon Longitudinal Study of Parents and Children (ALSPAC) at age 18. Data was available for 1049-1927 participants and for the 2- and 3-back versions of the task. Using multiple and multi-level regression controlling for important confounders we examined the association between APOE genotype on accuracy and reaction times. There was no evidence of a genotype effect on accuracy when the two difficulty levels were examined separately. There was some evidence to support a deleterious effect of the ε4 allele on n-back accuracy in the multi-level regression. There was weak evidence that the ε22 group were less accurate but the numbers were very low in this group. The ε34 group had faster reaction times than the reference ε33 group in all adjusted analyses but the ε44 group were only faster in the 3-back condition in multi-level analyses. There was no evidence of benefit in ε4 carriers, but there was some evidence of a detrimental effect on working memory in this large study.
    PLoS ONE 08/2015; 10(8):e0135894. DOI:10.1371/journal.pone.0135894 · 3.23 Impact Factor
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    ABSTRACT: To investigate the relationship between objectively-assessed alcohol consumption and perception of attractiveness in naturalistic drinking environments, and to determine the feasibility and acceptability of conducting a large-scale study in these environments. Observational study conducted simultaneously across three public houses in Bristol, UK. Participants were required to rate the attractiveness of male and female face stimuli and landscape stimuli administered via an Android tablet computer application, after which their expired breath alcohol concentration (BrAC) was measured. Linear regression revealed no clear evidence for relationships between alcohol consumption and either overall perception of attractiveness for stimuli, for faces specifically, or for opposite-sex faces. The naturalistic research methodology was feasible, with high levels of participant engagement and enjoyment. We found no evidence for a relationship between alcohol consumption and perception of attractiveness in our large-scale naturalistic study. Our study is important given the large sample size, the successful translation of an experimental, laboratory-based paradigm to a naturalistic drinking environment and the high level of public engagement with the study. Future studies should use similarly ecologically-valid methodologies to further explore the conditions under which this effect may be observed and identify the mechanisms underlying any relationships. © The Author 2015. Medical Council on Alcohol and Oxford University Press.
    Alcohol and Alcoholism 08/2015; DOI:10.1093/alcalc/agv096 · 2.89 Impact Factor
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    ABSTRACT: Cognitive bias modification (CBM) techniques, which experimentally retrain abnormal processing of affective stimuli, are becoming established for various psychiatric disorders. Such techniques have not yet been applied to maternal processing of infant emotion, which is affected by various psychiatric disorders. In a pilot study, mothers of children under 3 years old (n = 32) were recruited and randomly allocated to one of three training exercises, aiming either to increase or decrease their threshold of perceiving distress in a morphed continuum of 15 infant facial images. Differences between pre- and post-training threshold were analysed between and within subjects. Compared to baseline thresholds, the threshold for perceiving infant distress decreased in the lowered threshold group (mean difference -1.7 frames, 95 % confidence intervals (CI) -3.1 to -0.3, p = 0.02), increased in the raised threshold group (1.3 frames, 95 % CI 0.6 to 2.1, p < 0.01) and was unchanged in the control group (0.1 frames, 95 % CI -0.8 to 1.1, p = 0.80). Between-group differences were similarly robust in regression models and were not attenuated by potential confounders. The findings suggest that it is possible to change the threshold at which mothers perceive ambiguous infant faces as distressed, either to increase or decrease sensitivity to distress. This small study was intended to provide proof of concept (i.e. that it is possible to alter a mother's perception of infant distress). Questions remain as to whether the effects persist beyond the immediate experimental session, have an impact on maternal behaviour and could be used in clinical samples to improve maternal sensitivity and child outcomes.
    Archives of Women s Mental Health 08/2015; DOI:10.1007/s00737-015-0565-5 · 2.16 Impact Factor
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    ABSTRACT: To investigate, using a Mendelian randomisation approach, whether heavier smoking is associated with a range of regional adiposity phenotypes, in particular those related to abdominal adiposity. Mendelian randomisation meta-analyses using a genetic variant (rs16969968/rs1051730 in the CHRNA5-CHRNA3-CHRNB4 gene region) as a proxy for smoking heaviness, of the associations of smoking heaviness with a range of adiposity phenotypes. 148 731 current, former and never-smokers of European ancestry aged ≥16 years from 29 studies in the consortium for Causal Analysis Research in Tobacco and Alcohol (CARTA). Waist and hip circumferences, and waist-hip ratio. The data included up to 66 809 never-smokers, 43 009 former smokers and 38 913 current daily cigarette smokers. Among current smokers, for each extra minor allele, the geometric mean was lower for waist circumference by -0.40% (95% CI -0.57% to -0.22%), with effects on hip circumference, waist-hip ratio and body mass index (BMI) being -0.31% (95% CI -0.42% to -0.19), -0.08% (-0.19% to 0.03%) and -0.74% (-0.96% to -0.51%), respectively. In contrast, among never-smokers, these effects were higher by 0.23% (0.09% to 0.36%), 0.17% (0.08% to 0.26%), 0.07% (-0.01% to 0.15%) and 0.35% (0.18% to 0.52%), respectively. When adjusting the three central adiposity measures for BMI, the effects among current smokers changed direction and were higher by 0.14% (0.05% to 0.22%) for waist circumference, 0.02% (-0.05% to 0.08%) for hip circumference and 0.10% (0.02% to 0.19%) for waist-hip ratio, for each extra minor allele. For a given BMI, a gene variant associated with increased cigarette consumption was associated with increased waist circumference. Smoking in an effort to control weight may lead to accumulation of central adiposity. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to
    BMJ Open 08/2015; 5(8):e008808. DOI:10.1136/bmjopen-2015-008808 · 2.27 Impact Factor
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    ABSTRACT: To investigate cross-sectional and longitudinal associations between personality and smoking, and test whether sociodemographic factors modify these associations. Cross-sectional and longitudinal individual-participant meta-analysis. Nine cohort studies from Australia, Germany, UK and US. A total of 79,757 men and women (mean age = 51 years). Personality traits of the Five-Factor Model (extraversion, neuroticism, agreeableness, conscientiousness and openness to experience) were used as exposures. Outcomes were current smoking status (current smoker, ex-smoker, and never smoker), smoking initiation, smoking relapse, and smoking cessation. Associations between personality and smoking were modeled using logistic and multinomial logistic regression, and study-specific findings were combined using random-effect meta-analysis. Current smoking was associated with higher extraversion (odds ratio per 1 standard deviation increase in the score: 1.16; 95% confidence interval: 1.08-1.24), higher neuroticism (1.19; 1.13-1.26), and lower conscientiousness (0.88; 0.83-0.94). Among nonsmokers, smoking initiation during the follow-up period was prospectively predicted by higher extraversion (1.22; 1.04-1.43) and lower conscientiousness (0.80; 0.68-0.93), whereas higher neuroticism (1.16; 1.04-1.30) predicted smoking relapse among ex-smokers. Among smokers, smoking cessation was negatively associated with neuroticism (0.91; 0.87-0.96). Sociodemographic variables did not appear to modify the associations between personality and smoking. Adult smokers have higher extraversion, higher neuroticism and lower conscientiousness personality scores than non-smokers. Initiation into smoking is positively associated with higher extraversion and lower conscientiousness, while relapse to smoking among ex-smokers is association with higher neuroticism. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Addiction 07/2015; 110(11). DOI:10.1111/add.13079 · 4.74 Impact Factor
  • Suzanne H Gage · Marcus R Munafò ·

    The Lancet Psychiatry 07/2015; 2(9). DOI:10.1016/S2215-0366(15)00333-8
  • Angela S Attwood · Marcus R Munafò ·

    Journal of clinical epidemiology 07/2015; DOI:10.1016/j.jclinepi.2015.04.016 · 3.42 Impact Factor
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    Katherine S Button · Marcus R Munafò ·
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    ABSTRACT: A recent network meta-analysis by Zhu and colleagues reported in the Shanghai Archives of Psychiatry compared two different comparators (psychological placebo and waitlist control) in trials assessing the effectiveness of cognitive behavioral therapy (CBT) for the treatment of generalized anxiety disorder (GAD). CBT was superior to both of these control conditions, but psychological placebo was superior to waitlist. However, we argue that the term 'psychological placebo' is a misnomer because the impossibility of effectively blinding participants to treatment allocation in CBT trials makes it impossible to control for placebo effects. This failure to blind participants and therapists - and the resultant high risk of bias - was the main reason Zhu and colleagues found that the overall quality of the evidence supporting the conclusion that CBT is effective for GAD is poor. This is a general problem in all psychotherapy trials, which suffer from well-documented methodological and conceptual problems that prevent adequate placebo control and undermine casual inference. We discuss these problems and suggest potential solutions. We conclude that, while it may be difficult to remove potential bias in randomized controlled trials of psychotherapy, we can improve on the status quo by integrating basic science within applied trials to adjust for these biases and, thus, improve the strength of the causal inferences.
    Shanghai Archives of Psychiatry 06/2015; 27(3):144-8. DOI:10.11919/j.issn.1002-0829.215042

Publication Stats

9k Citations
1,602.51 Total Impact Points


  • 2005-2015
    • University of Bristol
      • School of Experimental Psychology
      Bristol, England, United Kingdom
  • 2011
    • University of Bath
      • Department of Psychology
      Bath, ENG, United Kingdom
  • 2008
    • University of Cambridge
      • Department of Psychiatry
      Cambridge, ENG, United Kingdom
  • 2003-2008
    • University of Oxford
      • • Wellcome Trust Centre for Human Genetics
      • • Department of Psychiatry
      • • Clinical Genetics Research Group
      Oxford, England, United Kingdom
  • 2007
    • Massachusetts General Hospital
      • Tobacco Research and Treatment Center
      Boston, Massachusetts, United States
    • University of Birmingham
      Birmingham, England, United Kingdom
    • Brown University
      Providence, Rhode Island, United States
  • 1998-2003
    • University of Southampton
      • Department of Psychology
      Southampton, England, United Kingdom