Parrott - Overview
Professor Andy Parrott
is an international authority on the human psychobiology of MDMA or Ecstasy. He has published
numerous research papers on its recreational use, including the first to
demonstrate memory impairments in young Ecstasy/MDMA users compared to similar
aged controls. These research findings have been presented at numerous
conferences in the
Professor Andy Parrott’s other main field of research expertise is the psychobiology of nicotine dependency. In an extensive research program, he has shown how cigarette smoking causes increased stress and depression. Furthermore the explanatory model of nicotine dependency which he has proposed, explains why cigarette smoking can generate so many psychological problems in smokers. These findings have been presented in numerous journal articles and conference papers.
In total, he has over 300 journal articles, book chapters, and conference papers. They cover the main classes of psychoactive drug, including CNS stimulants such as amphetamine, CNS depressants such as alcohol and benzodiazepines, antipsychotic drugs for schizophrenia, antidepressants, cognitive enhancers, anabolic steroids, and recreational drugs such as cannabis, LSD and ketamine. He has also written a leading European textbook on this area, published by John Wiley, entitled: ‘Understanding Drugs and Behaviour’, with co-authors Andy Scholey, Alun Morinan, and Mark Moss.
The research papers are presented in the following groups
Cigarette smoking and nicotine dependency.
Other psychoactive drugs.
Copyright for all the articles is owned by the various journal publishers.
The PDF files are attached to this webpage through
various permissions and journal subscriptions by
Thanks in particular to: Springer-Verlag (Psychopharmacology), Sage (Journal of Psychopharmacology), Wiley (Human Psychopharmacology), and many other publishers (other journals)
The first Ecstasy/MDMA review article in Neuropsychobiology was published in 2000, and was based on the first Novartis Foundation symposium meeting.
The second review in 2001 was a more comprehensive review, which attempted to cover human MDMA research from the very first studies 15 years earlier. It presents a broad overview of the area, and remains in the top ten list of cited articles from the journal Human Psychopharmacology.
The 2002 article covered the serotonin syndrome, and was the second most highly cited paper for the journal Pharmacology Biochemistry, and Behaviour, that year.
The 2004 paper in Psychopharmacology examines the question of whether Ecstasy tablets contain MDMA.
The 2005 Journal of Psychopharmacology article on chronic tolerance, explains why ecstasy users often increase their dosage, yet find it less effective over time.
The 2006 review in the Journal of Psychopharmacology focused on research between 2001-2005, and integrated the findings into an explanatory model for MDMA based around metabolic stress.
The Editorial & commentary in the Journal of Psychopharmacology discussed the relative psychobiological costs of alcohol, Ecstasy/MDMA, and Aldous Huxley’s euphoriant ‘soma’.
The 2007 paper in Psychopharmacology critically evaluated the proposal that MDMA might be useful as an adjunct for psychotherapy.
Parrott, A.C. (2000). Human Research on MDMA Neurotoxicity: Cognitive and Behavioural indices of change. Neuropsychobiology, 42, 17-24. PDF
Turner, J.J.D. & Parrott, A.C. (2000) The neurotoxicity of MDMA ("Ecstasy") in humans: Viewpoints of the discussants. Neuropsychobiology, 42, 42-47. PDF
Parrott AC (2001). Human Psychopharmacology of MDMA (Ecstasy): a review of fifteen years of empirical research. Human Psychopharmacology, 16, 557-577. PDF
Parrott AC (2002). Recreational MDMA (Ecstasy), the serotonin syndrome, and serotonergic neurotoxicity. Pharmacology, Biochemistry and Behavior, 71, 837-844. PDF
Parrott AC (2002) The long term effects of ecstasy/MDMA are real and
psychobiologically damaging. Note: the title was amended by the journal editors
to: 'Very real, very damaging'. The Psychologist, 15, 472-473. PDF
Parrott AC (2004). Is Ecstasy MDMA ? A review of the proportion of ecstasy tablets containing MDMA, their dosage levels , and the changing perceptions of purity. Psychopharmacology, 173, 234-241. PDF
Parrott AC (2005). Chronic tolerance to recreational MDMA (3,4-methylenedioxymethamphetamine) or Ecstasy. Journal of Psychopharmacology, 19, 71-83. PDF
Parrott AC, Marsden C (2006) MDMA (3,4-methylenedioxymethamphetamine) or Ecstasy: the contemporary human and animal research perspective. Journal of Psychopharmacology 20: 143-146. PDF
Parrott AC (2006). MDMA in humans: factors which influence the neuropsychobiological profiles of recreational Ecstasy users, the integrative role of bio-energetic stress. Journal of Psychopharmacology 20: 147-163 PDF
Parrott AC (2007). Ecstasy versus alcohol: Tolstoy and the variations in unhappiness. Journal of Psychopharmacology 21: 3-6. PDF
(commentary on an earlier JoP Editorial by Nutt DM PDF ).
Parrott AC (2007). Alcohol, ecstasy, Aldous Huxley’s ‘soma’. Journal of Psychopharmacology 21: 8-9. PDF
(also see David Nutt’s reply PDF ).
Parrott AC (2007). The psychotherapeutic potential of MDMA (3,4-methylendioxymethapmphetamine): an evidence based review. Psychopharmacology 191: 181-194. PDF
Memory and cognition in Ecstasy/MDMA users.
In one of our earliest studies, we administered
the Cognitive Drug Research test battery to abstinent Ecstasy/MDMA users and
nonuser controls. On most tasks the
groups were very similar, but on immediate and delayed word recall, the Ecstasy
users were significantly impaired. There was a prior clinical report from
This initial report of memory deficits was
confirmed in a follow-up study undertaken by Joanna Lasky. This Psychopharmacology article remains one
of their most highly cited papers. In a series of further investigations,
Professor Parrott’s group at the University of East London (UEL), where he was
then based, investigated the nature of these cognitive/memory changes in more
detail. The studies involved a wide variety of cognitive tasks, covering skills
such as executive planning, visual vigilance, psychomotor integrity, and
different aspects of memory. This programme was co-led by Dr. John Turner,
research collaborator and Senior Lecturer at UEL. Their first postgraduate
research student in this area, Helen Fox, undertook a number of ground-breaking
studies. Helen compared regular Ecstasy users who complained of drug-related
problems, with an equivalent group of Ecstasy users who did not complain of any
drug-related problem. Against predictions, the cognitive/memory scores for
these two groups were very similar. Memory deficits were evident, but these
were related to the amount of Ecstasy taken, irrespective of whether the
individual complained of problems. Helen and her supervisors (AP and JT) were
awarded the BAP prize in 2002 for the resulting Journal of Psychopharmacology paper. Helen then established links with Barbara
Sahakian's Neuropsychology Group at
Parrott AC (1996). MDMA, mood and memory: the agnosia of the Ecstasy. Annual Scientific Meeting of the Psychobiology Section of the British Psychological Society, September 1996. British Psychological Society Proceedings (2007), 5, p49.
Parrott AC (1997). Ecstatic but memory depleted ? The Psychologist, 10, 265.
Parrott AC, Lees A, Garnham NJ, Jones M, Wesnes K (1998). Cognitive performance in drug-free recreational Ecstasy (MDMA) users: evidence for memory deficits. Journal of Psychopharmacology, 12, 79-83. PDF
Parrott AC, Lasky J (1998). Ecstasy (MDMA) effects upon mood and cognition: before, during, and after a Saturday night dance. Psychopharmacology, 138, 261-268. PDF
Fox HC, Parrott AC, Turner JJD (2001). Ecstasy use: cognitive deficits related to dosage rather than awareness of problems. Journal of Psychopharmacology, 15, 273-281. PDF
Fox HC, Toplis AS, Turner JJD, Parrott AC (2001). Auditory verbal learning in drug-free recreational Ecstasy polydrug users. Human Psychopharmacology, 16, 613-618. PDF
Fox HC, McLean A, Turner, JJD, Parrott AC, Rogers R, Sahakian BJ (2002) Neuropsychological evidence of a relatively selective profile of temporal dysfunction in drug-free MDMA (ecstasy) polydrug users. Psychopharmacology 162, 203-214. PDF
Fox HC, Turner JJD, Parrott AC (2003). Prepulse inhibition of acoustic startle in drug free Ecstasy polydrug users. Adiktologie, 3, 13-19.
Parrott AC, Fox HC, Milani RM (2003). Cannabis, Ecstasy/MDMA, and memory: commentary on Simon and Mattick’s recent study. Addiction 98, 1003-1005. PDF
Parrott AC (2003). Cognitive decline and cognitive normality in recreational cannabis and Ecstasy/MDMA users. Human Psychopharmacology, 18, 89-90. PDF
Parrott AC, Gouzoulis-Meyfrank E, Rodgers J, Solowij N. (2004). Ecstasy/MDMA and cannabis: the complexities of their interactive neuropsychobiological effects. Journal of Psychopharmacology, 18, 575-575. PDF
Parrott AC, Milani RM, Gouzoulis-Meyfrank E, Daumann J. (2007). Cannabis and Ecstasy/MDMA ((3,4-methylenedioxymethamphetamine): an analysis of their neuropsychobiological interactions in recreational users. Journal of Neural Transmission PDF
Self-reports by recreational Ecstasy/MDMA users.
In our very first Ecstasy study, undertaken by Darren Davison in 1992-3, recreational MDMA users were given structured interviews which covered their psychological and physiological experiences, on-drug and off-drug. They also completed a mood adjective checklist to describe their feelings on-Ecstasy. They were followed in subsequent years by a number of further studies, by Malcolm Stuart and others.
In 2000, Dr Jacqui Rodgers from
Parrott AC, Davison D (1995). Profile of mood states of Ecstasy (MDMA) users. Journal of Psychopharmacology, 9, a48.
Parrott, A.C. (1996) Ecstasy (MDMA): Self-rated mood effects in recreational drug users. Journal of Psychophysiology, 10, 77.
Davison D, Parrott AC (1997). Ecstasy (MDMA) in recreational users; self-reported psychological and physiological effects. Human Psychopharmacology, 12, 221-226. PDF
Parrott AC, Stuart M (1997). Ecstasy (MDMA), amphetamine and LSD: comparative mood profiles in recreational polydrug users. Human Psychopharmacology, 12, 501-504. PDF
Rodgers J, Buchanan T, Scholey AB, Heffernan TM, Ling J, Parrott AC (2001). Differential effects of Ecstasy and cannabis on self-reports of memory ability: a web based study. Human Psychopharmacology, 16, 619-625. PDF
Parrott AC, Buchanan T, Scholey AB, Heffernan TM, Ling J, Rodgers J (2002). Ecstasy/MDMA attributed problems reported by novice, moderate and heavy users. Human Psychopharmacology, 17, 309-312. PDF
Rodgers J, Buchanan T, Scholey AB, Heffernan TM, Ling J, Parrott AC (2003). Patterns of drug use and the influence of gender on self-reports of memory ability in ecstasy users: a web based study. Journal of Psychopharmacology 17, 389-396. PDF
Parrott AC, Buchanan T, Heffernan TM, Scholey A, Ling J, Rodgers J (2003). Parkinson’s disorder, psychomotor problems, and dopaminergic neurotoxicity in recreational Ecstasy/MDMA users. Psychopharmacology, 167, 449-450.
Buchanan T, Ali T, Heffernan TM, Ling J, Parrott AC, Rodgers J, Scholey AB (2005). Non equivalence of online and pencil-and-paper tests: the case of the Prospective Memory Questionnaire. Behavioural Methods and Research Instrumentation. 37, 148-154.
Rodgers J, Buchanan T, Pearson C, Parrott AC, Ling J, Heffernan T, Scholey AB (2006). Differential experiences of the psychobiological sequelae of ecstasy use: quantitative and qualitative data from an internet study. Journal of Psychopharmacology 20: 437-446. PDF
Psychiatric distress in recreational Ecstasy polydrug users.
We have undertaken several studies into the psychological
well-being and psychiatric status of young recreational Ecstasy users. Elaine
Sisk assessed youngsters from a town in
Kirstie Soar undertook a series of studies into
the clinical well-being of heavy MDMA users, some of whom complained of
drug-related problems. Kirstie has also reviewed the literature on clinical
case studies. Since award of her PhD, Kirstie has been employed as a full-time
Lecturer in the Psychology Department at the
Parrott, A.C., Sisk, E., Turner, J.J.D. (2000) Psychiatric problems in heavy "Ecstasy" (MDMA) Polydrug users. Drug and Alcohol Dependence, 60, 105-110. PDF
Parrott AC, Milani RM, Parmar R, Turner JJD (2001).
Recreational Ecstasy/MDMA and other drug users form the
Soar K, Turner JJD, Parrott AC (2001). Psychiatric disorders in Ecstasy (MDMA) users: a literature review focusing upon personal predispositions and drug histories. Human Psychopharmacology, 16, 641-645. PDF
Parrott AC, Milani RM, Turner JJD (2002). Ecstasy and the SCL-90 findings: a reply to Cole. Psychopharmacology 162, 218-222. PDF
Milani RM, Parrott AC, Turner JJD, Fox HC (2004). Gender differences in self-reported anxiety, depression and somatization among ecstasy/MDMA polydrug users, alcohol/tobacco users, and nondrug users. Addictive Behaviors, 29, 965-971. PDF
Soar K, Parrott AC, Fox HC (2004). Persistent neuropsychological problems after seven years of abstinence from recreational Ecstasy (MDMA): a case study. Psychological Reports, 95, 192-196.
Milani RM, Parrott AC, Schifano F, Turner JJD (2005). Patterns of cannabis use in ecstasy polydrug users: moderate cannabis use may compensate for self-rated aggression and somatic symptoms. Human Psychopharmacology 20: 249-261. PDF
Parrott AC, Rowe KL,
Ecstasy/MDMA use in dance clubs.
In 1997, we tested a group of recreational drug users before they went out dancing/clubbing, at the club following self-administered drug, then 2 days and 7 days afterwards. The aim was to prospectively monitor any changes in self-rated mood states and cognitive skills over time. The moods of the control group, mostly social drinkers, were steady over the week. They reported having a good time at the dance club, and few adverse effects 2 and 7 days later. In contrast the moods of the Ecstasy users fluctuated markedly over time. They reported excellent moods at the club - although not significantly better than controls. Midweek they reported numerous adverse moods, some of which were quite severe. Cognitive skills were assessed on a hand held microcomputer, and significant memory impairments were evident at every session, probably due to their regular use of MDMA.
Following the first study in
In another www article with Jacqui Rodgers, we
noted how more memory problems were reported by those who danced the most while
on MDMA. The close links between Ecstasy and dance clubbing have been debated
in two review articles. The 2002 paper outlined how acute doses of MDMA can
cause an acute reaction with many parallels with the serotonin syndrome. The
2004 paper debated the psychobiological implications of taking MDMA in hot and
crowded conditions, such as those found in dance clubs and raves. These studies have involved close
collaboration with Professor Johannes Thome and Dr. Christian Kissling from the
Parrott AC, Lasky J (1998). Ecstasy (MDMA) effects upon mood and cognition: before, during and after a Saturday night dance. Psychopharmacology, 139, 261-268. PDF
Parrott AC (2004). MDMA (3,4-methylenedioxymethamphetamine) or Ecstasy: the neuropsychobiological implications of taking it at raves. Neuropsychobiology, 50, 329-335. PDF
Parrott AC, Young L (2005). Increased body temperature in recreational Ecstasy/MDMA users out clubbing and dancing. Journal of Psychopharmacology, 19, a26.
Parrott AC, Rodgers J,
Buchanan T, Ling J, Heffernan T,
Lock J, Kissling C, Thome J, Parrott, AC (2006). Cortisol, testosterone and mood changes in Ecstasy-MDMA users at a Saturday night dance club: a brief prospective study. Journal of Psychopharmacology, 20, a52.
Parrott AC, Burgess A, Edwards RL, Jones H (2007). EEG theta amplitude reduced in cannabis and cannabis-ecstasy polydrug users undertaking a recognition memory task. Journal of Psychopharmacology (in press).
Parrott AC, Adnum L, Evans A, Kissling C, Thome J (2007). Heavy ecstasy-MDMA use at cool house parties: Substantial cortisol release and increased body temperature. Journal of Psychopharmacology (in press).
Ecstasy/MDMA conferences and symposia.
Andy Parrott has proposed, and arranged the programs for, the following Ecstasy/MDMA symposia.
Drugs of Use and Abuse" (with Martin Yeomans). British Psychological
Society Annual Conference.
Psychobiology of Ecstasy or MDMA". British Psychological Society Annual
1998. "MDMA (Ecstasy): a Human Neurotoxin
?". Novartis Foundation,
Neuropsychopharmacology of MDMA (Ecstasy)".
2004 “Neuropsychiatric and psychobiological aspects of recreational cannabis and ecstasy use”. International Congress of Biological Psychiatry. Sydney Australia.
“Ecstasy: benign pleasure or potential plague” (with Richard Green and Charles
Marsden). British Association for Psychopharmacology Annual Conference,
International Conference Centre. Harrogate
“MDMA/Ecstasy: the human and animal research interface”. Novartis
“Memory and Ecstasy/MDMA”. International Conference on Memory; fourth
Nicotine dependency: the psychobiological problems caused by cigarette smoking
The cigarette smoking research is primarily concerned with the adverse effects of nicotine on mood and cognition. Many research groups state that smoking helps with mood control. However in an extensive series of studies, Prof. Andy Parrott has shown the central role of psychobiological vacillation, so that tobacco smoking can actually cause many forms of psychological distress. Cigarette smokers only feel 'normal' when replete with nicotine, and in-between cigarettes their moods soon deteriorate. The apparent mood gains of smoke inhalation, only represent the temporary return to psychological normality. In between cigarettes, smokers experience increasing levels of psychobiological distress, with frequent cravings. Nicotine dependency therefore directly causes smokers to experience greater moodiness, irritability, anger and depression each day. This helps to explain why adolescent smokers become more stressed a year after they have taken up smoking. Also why adult smokers are significantly more stressed than adult nonsmokers. Finally, quitting smoking gradually leads to reduced stress - after the immediate post-cessation period of strong cravings has subsided. Nicotine dependency also causes memory problems, so your memory should also improve once you quit.
There are some simple messages for tobacco smokers. Firstly, do not smoke. The tar and carbon monoxide in cigarette smoking will soon damage your heart and lungs. The adverse effects on breathing can be measuring within a few months of taking-up smoking. Your skin will become wrinkly, and impaired blood supply to the penis may lead to impotence. These adverse medical effects may kill you. The probability of a smoker dying from a tobacco-related disease is around 50%. In psychological terms, nicotine dependency will cause you to feel moody, irritable and stressed, each day.
My advice is to quit immediately. Your physical health will start to recover within a few weeks. Over successive months your breathing and health will continue to improve. You will feel much better. Your chances of heart disease and cancer will drop dramatically. The long-term health benefits of cessation are well documented.
What is less well known is that your psychological well-being will also improve after quitting. These mood improvements will take between a few weeks and several months to occur, depending on the severity of your dependency. It will be a gradual process, so you will need to persevere. Initially you may suffer from strong cravings every day, and increased stress for several weeks, but these problems will gradually disappear over time. Once you have permanently quit – you will feel less moody, less irritable, more contented, and less prone to depression.
Parrott AC (1999). Does cigarette smoking cause stress ? American Psychologist, 54, 817-820.
Parrott, A.C. (2000) Cigarette smoking does cause stress. American Psychologist, 55, 1159-1160.
Parrott, A.C. (2000) Smoking and adverse childhood experiences. Letter to the Editor: Journal of the American Medical Association, 283.
Parrott, A.C. (2001)
Cigarette smoking/nicotine dependency: A direct cause of stress and
Parrott AC (2003). Cigarette-derived nicotine is not a medicine. World Journal of Biological Psychiatry, 4, 49-55. PDF (note: PDF file covers the whole journal issue, so print pages 49-55).
Parrott AC (2004). Heightened stress and depression follow cigarette smoking. Psychological Reports, 94, 33-34.
Parrott AC (2006). Nicotine psychobiology: how chronic-dose prospective studies can illuminate some of the theoretical issues from acute dose research. Psychopharmacology 184, 567-576. PDF
Cigarette use and psychobiological vacillation over the day.
The original studies which led to the above model, investigated the mood effects of cigarettes smoked over the day. Smokers went about their normal activities, and smoked cigarettes normally. Before each cigarette they complete a brief mood scale to indicate their current feelings of stress, arousal, and pleasure. Then immediately after each cigarette, they complete the same mood scale. This design allowed the effects of each cigarette and every period of abstinence, to be determined. This novel methodology revealed that smokers suffered repeated mood deteriorations in-between cigarettes, and transitory mood improvements immediately after smoking. Heavy smokers reported the worst mood states in between cigarettes, but also the greatest mood normalization, which explains why their 'need' for cigarettes was strongest.
In later studies, we compared the daily mood patterns of cigarette smokers and nonsmokers. They provided comparative data on the daily moods experienced by cigarette smokers and nonsmokers. Some studies were conducted during the day, from breakfast to bedtime. Others were conducted with night shift workers. It was found that non-deprived smokers were generally similar to nonsmokers, whereas deprived smokers were significantly worse than either group. Thus smoking simply allowed normal/average moods to be maintained. Nicotine did not provide any real mood gains, whereas abstinent smokers suffered from increased stress, depression, and irritability. Furthermore, in some situations (e.g. night shift-workers), the moods of the active smokers were significantly worse than those of the nonsmokers.
Parrott AC (1993). Cigarette smoking: effects upon self-rated feelings of stress and arousal over the day. Addictive Behaviors, 18, 389-395.
Parrott AC, Joyce C (1993). Diurnal patterns of stress and arousal in cigarette smokers, deprived smokers, and non-smokers. Human Psychopharmacology, 8, 21-28. PDF
Parrott AC (1994). Does cigarette smoking cause stress ? Addiction, 89, 142-144. PDF
Parrott AC (1994). Individual differences in stress and arousal during cigarette smoking. Psychopharmacology, 115, 389-396. PDF
Parrott AC (1994). Acute pharmacodynamic tolerance to the subjective effects of cigarette smoking. Psychopharmacology, 116, 93-97. PDF
Parrott AC (1995). Stress modulation over the day in cigarette smokers. Addiction, 90, 233-244.
Parrott AC (1995). Smoking cessation leads to reduced stress, but why ? International Journal of the Addictions, 30, 1509-1516.
Parrott AC, Garnham NJ, Wesnes K, Pincock C (1996). Cigarette smoking and abstinence: comparative effects upon cognitive task performance and mood state over 24 hours. Human Psychopharmacology, 11, 391-400. PDF
Jones MEE, Parrott AC (1997). Stress and arousal rhythms in smokers and nonsmokers working day and night shifts. Stress Medicine, 13, 91-97 PDF
Parrott, A.C. (2000) Cigarette smoking: The gradual evolution of a research programme. Psych-Talk, 24, 25-28. PDF
Parrott, A.C. (2000) Tobacco/Nicotine Dependency: A direct cause of Psychobiological Distress? Psych-Talk, 24, 29-31.
Cognitive skills of cigarette smokers and Nesbitt’s Paradox.
It has been suggested that nicotine is a cognitive enhancer, so that cigarettes provide smokers with a positive resource to boost their alertness. The empirical evidence for this notion is however very weak. We have therefore included cognitive tasks in many of our studies. In most studies, we found that the cognitive skills of deprived smokers were impaired, whereas the cognitive skills of the non-deprived smokers were similar to those of the nonsmokers. We have found some limited evidence for cognitive gains in smokers, although the evidence was not consistent, and generally we found no cognitive gains. Our overall conclusion is that although nicotine is potentially a cognitive enhancer, due to tolerance, regular smokers do not actually gain any real cognitive advantages from nicotine. Their cognitive abilities fluctuate – in a way similar to their mood states. So that they need regular hits of nicotine just to maintain normal levels of cognitive functioning. In Parrott (1998), I suggested that cognition was slightly improved post-cigarette, but then deteriorated in-between cigarettes, so that over the day cognition remained broadly neutral. Some of the relevant papers are listed in the above sections.
In the early 1970s, Nesbitt described a paradox which has confounded nicotine/smoking researchers for many years. Namely, how can cigarettes make smokers feel more alert and more relaxed at the same time ? Andy Parrott's research has offered a simple resolution for the Paradox. Abstinence makes the smoker less alert and more stressed/irritable. Smoke inhalation restores these moods to normal - for a brief period. Nesbitt's Paradox simly reflects the relief of unpleasant abstinence effects. No actual gains in alertness or relaxation are involved.
Parrott AC, Roberts G
(1991). Nicotine deprivation and nicotine reinstatement: effects upon a brief
sustained attention task. In: Effects of
nicotine on biological systems. Adlkofer F, Thurau K (eds), Birkhauser,
Parrott AC, Roberts G (1991). Smoking deprivation and cigarette reinstatement: effects upon visual attention. Journal of Psychopharmacology, 5, 402-407.
Parrott AC (1992). Smoking and smoking cessation: effects upon human performance. Journal of Smoking-Related Disorders, 3, 43-53.
O'Neill ST, Parrott AC (1992). Stress and arousal in sedative and stimulant cigarette smokers. Psychopharmacology, 107, 442-446. PDF
Wesnes K, Parrott AC
(1992). Smoking, nicotine and human performance. In: Handbook of human
performance, Vol 2. Smith A, Jones DM (eds). Academic press,
Parrott AC, Kaye F (1999). Daily uplifts, hassles, stresses, and cognitive failures, in cigarette smokers, abstaining smokers, and nonsmokers. Behavioral Pharmacology, 10, 639-646.
Parrott AC (1998). Nesbitt’s Paradox resolved ? stress and arousal modulation during cigarette smoking. Addiction, 93, 27-39. PDF
Heffernan TM, Ling J, Parrott AC, Buchanan T,
Nicotine withdrawal, Nicotine Gum, and Smoking Cessation
Since nicotine withdrawal leads to mood impairments in regular smokers, this raises the question of how long it takes for these psychobiological deficits to develop. Received wisdom was that it could take 12-24 hours for abstinence symptoms to be apparent, but there was very little empirical data on this question - tobacco companies are not interested in this particular question! In our first study, Natasha Garnham investigated the cognitive skills and moods states of abstinent smokers, at two hour intervals over the day. Significant deficits were apparent from the first session onwards, with symptoms tending to worsen as the period of abstinence lengthened. Jo Thurkle and Mark Ward covered the first three hours of abstinence, and found impairments at every session. Significant cognitive/mood abstinence symptoms occurred after just one hour without nicotine. We have also looked at mood control in psychiatric patients, finding that they experience severe abstinence symptoms after brief periods without cigarettes. In our most recent study, Mark Slater assessed abstinence symptoms under two conditions: environmental stressor (difficult problem solving), and environmental relaxation (soothing music); abstinence symptoms became significantly worse during the high stressor condition. Debbie Craig and Jo-Ann Coomber compared the effects of temporary abstinence from cigarettes, at two different stages of the menstrual cycle. Abstinence symptoms were far stronger pre-menstrually than mid-cycle, when female smokers also reported less difficulty in abstaining.
Nicotine substitution devices have been
developed to help people quit smoking. In an aelry series of studies, we
investigated the cognitive performance effects of 2mg and 4mg nicotine gum,
placebo gum, and normal cigarette smoking. Debbie Craig also established two
smoking cessation clinics at health centers in
Parrott AC, Winder G (1989). Nicotine chewing gum (2mg, 4mg) and cigarette smoking: comparative effects upon vigilance and heart rate. Psychopharmacology, 97, 257-261. PDF
Parrott AC, Craig D,
Haines M, Winder GM (1991). Nicotine pilocrilex gum and sustained attention. In: Effects of nicotine on biological
systems. Adlkofer F, Thurau K (eds), Birkhauser,
Parrott AC, Craig D (1992). Cigarette smoking and nicotine gum (0mg, 2mg, 4mg): effects upon four visual attention tasks. Neuropsychobiology, 25, 34-43.
Craig D, Parrott AC, Coomber JA (1992). Smoking cessation in women: effects of the menstrual cycle. International Journal of the Addictions, 27, 695-704.
Parrott AC, Craig D (1995). Psychological functions served by nicotine gum. Addictive Behaviors, 20, 271-278. PDF
Parrott AC (1995). Smoking cessation leads to reduced stress, but why ? International Journal of the Addictions, 30, 1509-1516.
AC (1996). Smoking cessation counseling. In: Bayne R, Horton I, Bimrose J
(eds.). New Directions in Counseling. Routledge,
A.C., Thurkle J. Ward M. (2000). Nicotine abstinence: time course of the mood
and cognitive performance changes over 3 hours. 22nd International Congress of
the Collegium Internationale Neuro-Psychopharmacologicum,
Other Psychoactive drugs
Caffeine use by day-shift workers and night-shift workers was investigated by Miranda Jones as part of her PhD. Other studies in her resaeh porgremmme involved nicotine use in shift workers. Some of these studies were supported by Unilever, who also provided the matched supplies of caffeinated and decaffeinated beverages.
Jones MEE, Parrott AC, Wesnes K (1997). The effects of caffeinated and decaffeinated tea and coffee on mood and cognition in shift workers. Paper presented at Annual Scientific Meeting of the Psychobiology Section of the British Psychological Society. British Psychological Society Proceedings.
Jones MEE, Parrott AC, Wesnes K (1997). The effects of caffeinated and decaffeinated beverages on cognitive performance, heart rate, and mood in shift workers. Paper presented at the Annual Conference of the British Association for Psychopharmacolgy. Journal of Psychopharmacology, 12, A42.
effects on human aggression were first investigated by
Precilla Choi, when she was an undergraduate student at UEL. She continued her
work at University College London,
Choi PYL, Parrott AC, Cowan D (1989). Adverse behavioural effects of anabolic steroids in athletes: a brief review. Clinical Sports Medicine, 1, 183-187.
Choi PYL, Parrott AC (1989). Illicit drug use in strength athletes (letter). British Journal of Psychiatry, 154, 732-733.
Choi PYL, Parrott AC, Cowan D (1990). High dose anabolic steroids in strength athletes: effects upon hostility and aggression. Human Psychopharmacology, 5, 349-356. PDF
Parrott AC, Choi PYL, Davies M (1994). Anabolic steroid use by amateur athletes: effects upon psychological mood states. Journal of Sports Medicine and Physical Fitness, 34, 292-298.
Wilson-Fearon C, Parrott AC (1999). Multiple drug use and dietary restraint in a Mr. Universe competitor: psychobiological effects. Perceptual and Motor Skills, 88, 579-580.
has been investigated in a number of studies. The first to be undertaken by
Andy Parrott were at
Alcohol was investiagated by Vered Murgraff, when she investigated the effects of "risky single occasion drinking" or binge drinking in young people, as part of her PhD. We have also found that smoking is associated with reduced memory ability.
Murgraff V, Parrott AC, Bennett P (1998). Risky single occasion drinking amongst young people: a broad overview of research findings. Alcohol and Alcoholism, 33, 1-12
Ling J, Heffernan TM, Buchanan T, Scholey AB, Rodgers J, Parrott AC (2003). Effects of alcohol on subjective ratings of prospective and everyday memory deficits. Alcoholism: Clinical and Experimental Research, 27, 970-974. PDF
Ketamine has been increasingly
used as a recreational drug in recent years. Ketamine is a dissociative
anaesthetic with powerful neurochemical
effects, and may cause long-lasting neuronal damage. Helena Hamilton has assessed the
cognitive integrity of drug-free ketamine abusers, in a collaborative study
with Keith Wesnes’ Cognitive Drug Research in
H, Turner JJD, Parrott AC, Hargaden N, Wesnes K (2000). Ketamine and polydrug
abusers: comparative cognitive profiles. Paper submitted to the British
Association for Psychopharmacolgy Annual Conference,
The reliability and validity of the cognitive performance tests used in human psychopharmacology, were reviewed in a series of papers, published in 1991.
Parrott AC (1987).
Assessment of psychological performance in applied situations. In: Human psychopharmacology: measures and
methods, vol 1. Hindmarch I, Stonier PD (eds). Wiley,
Parrott AC (1991). Performance tests in human psychopharmacology (1): Test reliability and standardisation. Human Psychopharmacology, 6, 1-9. PDF
Parrott AC (1991). Performance tests in human psychopharmacology (2): Content validity, criterion validity, and face validity. Human Psychopharmacology, 6, 91-98. PDF
Parrott AC (1991). Performance tests in human psychopharmacology (3): Construct validity and test interpretation. Human Psychopharmacology, 6, 197-207. PDF
Parrott AC (1991).
Psychoactive medicines: efficacy and side-effects. In: The Psychology of Health. Pitts M, Phillips K (eds). Routledge,
Parrott AC (1991).
Social drugs: effects upon health. In: The Psychology of Health. Pitts M,
Phillips K (eds). Routledge,
Scopolamine, Promethazine, Cinnarazine.
These studies were conducted when Andy Parrott
was Senior Psychologist at the
Parrott AC, Jones R (1985). Effects of transdermal scopolamine upon psychological performance at sea. European Journal of Clinical Pharmacology, 28, 419-423.
Parrott AC (1986). The effects of transdermal scopolamine and four doses of oral scopolamine (0.15, 0.3, 0.6, 1.2mg) upon psychological performance. Psychopharmacology, 89, 347-354. PDF
Parrott AC (1986). Transdermal scopolamine: effects of single and repeated patches upon aspects of vision. Human Psychopharmacology, 1, 109-115. PDF
Parrott AC (1986). Transdermal scopolamine: effects of single and repeated patches upon psychological task performance. Neuropsychobiology, 17, 53-59.
Parrott AC, Wesnes K (1987). Promethazine, scopolamine and cinnarizine: comparative time course of psychological performance effects. Psychopharmacology, 92, 513-519. PDF
Parrott AC (1988). Transdermal scopolamine: effects upon psychological performance and visual functioning at sea. Human Psychopharmacology, 3, 119-125. PDF
Parrott AC (1989). Transdermal scopolamine: a review of its effects upon motion sickness, psychological performance, and physiological functioning. Aviation Space and Environmental Medicine, 60, 1-9.
Parrott AC, Golding JF, Pethybridge RJ (1990). The effects of single and repeated doses of oral scopolamine, cinnarizine and placebo upon psychological performance and physiological functioning. Human Psychopharmacology, 5, 207-216. PDF
The follow studies were undertaken at
Parrott AC, Hindmarch I (1975). Arousal and performance - the ubiquitous inverted-U relationship; changes in response latency and arousal level in normal subjects induced by CNS stimulants, sedatives and tranquillisers. IRCS Medical Science, 3, 176.
Hindmarch I, Parrott AC (1977). A repeated dose comparison of nomifensine, imipramine and placebo on subjective assessments of sleep and objective measures of psychomotor performance. British Journal of Clinical Pharmacology, 4, 167s-173s.
Hindmarch I, Parrott AC, Arenillas L (1977). A repeated dose comparison of dichloralphenazone, flunitrazepam, and amylobarbitone sodium, on aspects of sleep and early morning behaviour in normal subjects. British Journal of Clinical Pharmacology, 4, 229-233.
Parrott AC, Hindmarch I (1978). Factor analysis of a sleep evaluation questionnaire. Psychological Medicine, 8, 325-329.
Hindmarch I, Parrott AC (1978). A repeated dose comparison of the side effects of five antihistamines. Arzneimittel- Forschung (Drug Research), 28, 483-486.
Hindmarch I, Parrott AC (1979). The effects of repeated nocturnal doses of clobazam, dipotassium chlorazepate and placebo, on subjective ratings of sleep and early morning behaviour, and objective measures of arousal, psychomotor performance and anxiety. British Journal of Clinical Pharmacology, 8, 325-329.
Hindmarch I, Parrott AC, Lanza M (1979). The effects of an ergot alkaloid derivative (Hydergine) on aspects of psychomotor performance, arousal and cognitive processing ability. Journal of Clinical Pharmacology, 19, 726-732.
Parrott AC, Hindmarch I (1980). The Leeds Sleep Evaluation Questionnaire in psychopharmacological investigations - a review. Psychopharmacologia, 71, 173-179. PDF
Parrott AC, Rogers PJ,
Hindmarch I, Parrott AC, Stonier PD (1980). The effects of nomifensine and HOE 8476 upon car driving and related psychomotor performance. Royal Society of Medicine International Symposium Series, 25, 47-54.
Hindmarch I, Parrott
AC, Hickey B,
Parrott AC, Munton A (1981). Comparative effects of clobazam and diazepam upon psychological performance under different levels of background noise. Royal Society of Medicine International Symposium Series, 43, 53-57.
Parrott AC (1982). Critical flicker dusion thresholds and their relationship to other measures of alertness. Pharmacopsychiatry, 15, 39-43.
Parrott AC (1982). The effects of clobazam upon critical flicker fusion thresholds: a review. Drug Development Research (Supplement 1), 57-66. PDF
Parrott AC, Hindmarch I (1982). The effects of hydergine upon psychomotor performance, indices of alertness, and behaviour ratings, in studies involving normal and geriatric subjects. British Journal of Clinical Practice, 16, (Supplement), 18-20.
Parrott AC, Hindmarch I, Stonier PD (1982). Nomifensine, clobazam, and HOE 8476: effects on aspects of psychomotor performance and cognitive ability. European Journal of Clinical Pharmacology, 23, 309-313.
Stonier PD, Parrott AC, Hindmarch I (1982). Clobazam in combination with nomifensine (HOE 8476): effects on mood, sleep, and psychomotor performance related to car driving. Drug Development Research 1: 47-55. PDF
Parrott AC, Kentridge R (1982). Personal constructs of anxiety under the 1.5 benzodiazepine derivative clobazam, related to trait anxiety levels of the personality. Psychopharmacology, 78, 353-357. PDF
Parrott AC, Davies S (1983). Effects of a 1-5 benzodiazepine derivative upon performance in an experimental stress situation. Psychopharmacology, 79, 367-369. PDF
Parrott AC (1985). Clobazam, personality, stress and performance. Royal Society of Medicine International Symposium Series, 74, 47-58.
Parrott AC (1982). Effects of paintings and music, both alone and in combination, upon emotional judgements. Perceptual and Motor Skills, 54, 635-641.
Parrott AC (1989). Aesthetic responses to a series of paintings by Paul Klee. Perceptual and Motor Skills, 69, 339-348.
Parrott AC (1990). Diabetes management: viewpoint of the patient. Practical Diabetes, 7, 114-118.
Parrott AC (1994). Aesthetic responses to traditional and modern paintings by art experts and nonexperts. Perceptual and Motor Skills, 79, 297-298.