Understanding Drugs and Behaviour phần 3 potx

Regular smokers feel tense and irritable without nicotine,and cigarette smoke reverses these abstinence effects for a briefperiod.. in-Passive smoking Non-smokers who breathe air pollute

Key references and reading

Brice C and Smith A (2001) The effects of caffeine on simulated driving, subjective alertnessand sustained attention Human Psychopharmacology, 16, 523–531

Gupta BS and Gupta U (1999) Caffeine and Behaviour: Current Views and Research Trends.CRC Press, London

James JE (1994) Does caffeine enhance or merely restore degraded psychomotor performance?Neuropsychobiology, 30, 124–125

King GR and Ellinwood EH (1992) Amphetamines and other stimulants In: JH Lowinson and

P Ruiz (eds), Substance Abuse: A Comprehensive Textbook (pp 247–266) Williams &Wilkins, Baltimore

Snyder SH (1996) Stimulants Drugs and the Brain (pp 121–149) Freeman & Co., NewYork

Nicotine and

cigarette smoking

Overview

Cigarette smoking causes around 130,000 deaths each year in the

UK, yet worldwide the proportion of adults who smoke tobaccocontinues to increase Deaths are caused by tar and carbon

monoxide in the inhaled smoke Tar-induced deaths include lungcancer, throat cancer, jaw cancer, pneumonia and emphysema.Carbon monoxide reduces the oxygen-carrying capacity of theblood, causing circulatory problems in the heart and other organs.Therefore, numerous deaths occur through heart attack and

numerous limb amputations are required because of peripheraltissue death and gangrene Other smoke-induced problems includepremature skin wrinkling, erectile dysfunction and sexual impotence.Despite this, numerous children commence smoking between theages of 11 and 15, with female adolescents the main target groupfor tobacco advertisers Tobacco smoke generates a ‘‘hit’’ of nicotine

in the brain 7–10 seconds after inhalation Nicotine affects thenicotinic acetylcholine neurons in complex ways, with regularsmoking displaying a number of cholinergic adaptations For manyyears it was believed that nicotine relieved stress and boostedalertness However, it is now recognised that nicotine dependencecauses stress Thus, the feelings of contentment and relief on smokeinhalation only represent the reversal of unpleasant abstinenceeffects Regular smokers feel tense and irritable without nicotine,and cigarette smoke reverses these abstinence effects for a briefperiod The repeated experience of tension in-between cigarettescauses tobacco smokers to suffer from increased levels of daily stressand depression; this explains why adolescents who take up smokingbecome more stressed and depressed and why quitting smokingleads to enduring mood improvements However, stopping smokingcan be difficult, although successful cessation packages have beendevised They often employ nicotine substitute devices, such asgum, transdermal patches or nicotine inhalers Cigarette smokerswho manage to quit soon experience marked health improvements:better lung functioning, improved cardiac output and reduced rates

of cancer

it as clever and amusing, whereas others described it as disgusting King James I ofBritain in his Counterblaste to Tobacco described smoking as: ‘‘A custome lothsome tothe Nose, hermful to the Braine, dangerous to the Lungs, and of the blacke stinkingfume therof, neerest resembing the horrible Stigian smoke of the pit that is bottom-lesse.’’ Nevertheless, governments soon realised that it could provide a valuable source

of revenue, explaining why they are often loath to take effective action against it Pipesmoking, cigars and chewing tobacco were the main forms of consumption until the end

of the 19th century, but the development of commercial cigarette machines allowedcigarette smoking to gain its preponderance in the 20th century

The peak period of cigarette consumption in the UK was during the SecondWorld War, when 70% of adult males were smokers A proportion stopped smoking

at the end of the war when cigarettes were no longer given out free – the armed forceshad been provided with cigarettes as part of their rations Other smokers quit when itsadverse health effects became more widely known during the 1960s, with the UK and

US governments funding public education campaigns By the 1990s around 30% ofadult British males were smokers At the beginning of the 20th century few females usedtobacco, and it was a social taboo for women to be seen smoking in public With femaleemancipation the proportion of female smokers increased, so that by the mid-1990s,there were similar numbers of male and female smokers If current trends continue,female smokers will outnumber males during the 21st century; indeed, this is alreadyoccurring among the youngest age groups Female adolescents between the ages of 11and 15 are now the main target group for cigarette-advertising campaigns This genderimbalance is heightened by the less successful cessation rates in females

Adult rates of cigarette consumption have reduced in a few countries, such as theUSA, the UK, Australia and New Zealand, where anti-smoking health campaigns havebeen most prominent However, in many other Western countries, smoking is stillaccepted as the norm, even in otherwise enlightened Scandinavian societies, such asDenmark Throughout most of the Third World the proportion of adults who smoke isstill increasing, from the current estimated rate of 47% of adult males and 12% of adultfemales In China and many other developing countries the rates of cigarette smokingare particularly high, with local tobacco products very cheap and the more expensiveAmerican brands seen as status symbols

Adverse health effects

When organic plant matter is burnt the resulting smoke contains numerous chemicals,

including many that are poisonous and/or cancerous Over 400 chemicals have been

measured in unadulterated tobacco smoke; yet tobacco companies add chemicals, such

as ammonia, to intensify the nicotine hit Some of the chemical components of tobacco

smoke are listed in Mangan and Golding (1984) In health terms the two constituents of

most concern are carbon monoxide (CO) and tar: a generic term for the heavy organic

chemicals (such as nitrosamines) which form the visible smoke mist Around 4% of this

smoke comprises carbon monoxide (CO), which is readily taken up by the haemoglobin

in the red corpuscles of the blood Haemoglobin normally combines with oxygen in the

air to form oxyhaemoglobin, which is then transported by the circulation to all tissues

throughout the body The oxygen is then released, where it is utilised in basic cell

metabolism Without oxygen, cells are unable to undertake these fundamental

energy-dependent processes and eventually die Unfortunately, haemoglobin binds

with carbon monoxide far more readily than with oxygen, so that eventually 15% of

the haemoglobin of a heavy smoker is bound to carbon monoxide; this leads to oxygen

deficiency in peripheral tissues, gradually causing cell death in those regions served by

the smallest blood vessels Therefore, tobacco smokers develop premature skin ageing

and wrinkling – one of the health messages that most influences the attitudes of

adolescent females In males the blood supply to the penis is reduced, eventually

causing erectile dysfunction and sexual impotence – information that is far more

influential with adolescent males! These peripheral circulation problems also lead to

arteriosclerosis in the lower limbs, causing leg pains, tissue death and gangrene, which

then necessitates limb amputation; this can be prevented if the smoker immediately

stops smoking, since the blood supply rapidly improves However, if they continue

smoking a series of amputations may then be necessary: first, the toes and feet; then,

the leg below the knee; and, finally, the leg above the knee Around 500 limb

amputa-tions are undertaken in the UK each year for this reason There is an infamous

photograph of a smoker who has had both legs amputated and both arms surgically

removed because of smoking-induced circulatory problems, but who still continues to

smoke! The photo reveals him sitting in his chair, leaning toward a lit cigarette, held by

an ingenious wire contraption fixed around his neck

The heart is covered by an elaborate network of microcapillaries that supply it

with the large amounts of oxygen it needs Tobacco smoking reduces this crucial supply

of oxygen Thus, the single highest cause of death in tobacco smokers is cardiac arrest

or heart attack, while numerous other cardiac disorders occur in smokers Doll and

Peto (1976) reported the following incidence rates for heart disease in their classic study

of British doctors In the under-45 age group there were 7 per 100,000 of non-smokers,

41 per 100,000 of light smokers (1–14 cigarettes/day) and 104 per 100,000 of heavy

smokers (þ25 cigarettes/day) Similar trends were apparent in older age groups,

although the actual incidence rates were higher in every group, because of the

numerous factors that cause heart disease in middle and old age Smoking exacerbates

all circulatory disorders Diabetes mellitus leads to circulatory problems, so that heart

disease is considerably higher in diabetics than non-diabetics Tobacco exacerbates

these circulatory deficits, so that diabetic smokers suffer from even higher rates of

cardiac disorder and death Circulatory impairments can also affect brain functioning,

so that cigarette smokers suffer from increased rates of cerebrovascular stroke Carbonmonoxide crosses the placenta, so that the fetus suffers from oxygen deficits in itsdeveloping tissues Thus, pregnant smokers give birth to more stillborn babies, livebirths are generally underweight and the incidence of postnatal complications isincreased The placenta of smoking females tends to be larger than normal, possibly

as an adaptive mechanism to provide the developing fetus with oxygen

Tar is the other main component of tobacco smoke which makes it so lethal Tarcomprises the mist of heavy organic chemicals that form the visible smoke cloud Oninhalation, much of this tar settles on the respiratory tract as a sticky residue Onepractical demonstration of this is to ask a smoker to inhale though a handkerchief – aclear ring of black tar will be visible Then, ask them to exhale through a different part

of the handkerchief Far less tar will now be visible, indicating the amount of tar thathas been retained in the lungs These tar droplets are necessary to deliver nicotine intothe lungs Nicotine can only be absorbed once it has settled onto the lung surface asminute tar droplets; this explains why the correlation between tar and nicotine deliveryfor any brand of cigarette is always very high (r¼ þ0:90) Tar sticks to every part of theairways: lungs, upper bronchioles, tongue, gum, lips and throat Many of the con-stituents of tar are carcinogenic, particularly the nitrosamines (Mangan and Golding,1984) Cancers of all regions of the respiratory tract are thus markedly increased intobacco users, although the region mostly affected will depend on the exact mode oftobacco administration Cigarette smokers inhale smoke deep into their lungs and tend

to develop lung cancers Doll and Peto (1976) found that moderate smokers (15–24cigarettes/day) had 10 times the lung cancer rate compared with non-smokers, whereasheavy smokers (þ25 cigarettes/day) had 22 times the lung cancer rate for non-smokers.Pipe and cigar smokers retain the smoke in the mouth (for better nicotineabsorption from alkaline pipe/cigar smoke) and, thus, develop cancers in the mouthcavity and upper bronchioles Oral tobacco chewers also tend to develop cancers of thegums, lips and jaw Tobacco chewing is particularly prevalent in the southern states ofthe USA, with around 12 million regular tobacco chewers, but is also common in suchcountries as Sweden The wad of soggy tobacco tends to be held in one part of thecheek, and this is replaced when the nicotine supply is depleted Day after day, thecancerous tars from the soggy tobacco are concentrated in one small region of themouth, and this is where cancers often develop Furthermore, whereas lung cancerstake 20–30 years to commence, mouth cancers can develop after only 8–10 years oftobacco chewing Thus, many 20-year-old tobacco chewers develop cancers of thetongue, gum or jaw, which are difficult to treat medically Surgical removal of theaffected jaw region may be effective, although it is often unsuccessful

Tobacco companies promote low-tar cigarettes, which are used by many smokers

in the mistaken belief that they are less unhealthy However, these cigarettes use thesame tobacco leaves, the only difference being that low-tar cigarettes have numeroussmall air holes in front of the filter, so that the smoker inhales smoke diluted by air.Ultra low-tar cigarettes contain even more air holes, so that the tobacco smoke isfurther diluted Smokers compensate for this diluted smoke in several conscious andunconscious ways Many smokers partially cover the air holes with their fingers, so thatthe inhaled smoke contains a higher proportion of tar and nicotine than that stated onthe cigarette packet They also inhale more deeply and retain the smoke in their lungs

for longer The time between inhalations is also reduced, so that each cigarette is now

smoked more intensively Finally, more cigarettes are smoked each day, which is why

these brands are promoted so heavily by the tobacco industry These forms of

behavioural compensation are generally effective at maintaining desired nicotine

levels; but, this means that the smoker continues to inhale similar amounts of tar

and carbon monoxide Thus, there are few health gains for regular smokers who

move to low-tar brands The main effect is an increase the number of cigarettes

purchased and smoked each day (Table 5.1)

Table 5.1 Adverse medical effects of tobacco smoking, and health benefits of smoking cessation

Tar The nitrosamines and many other organic chemicals in tobacco

smoke cause various forms of cancer: cigarette smoking causescancers of the lung and upper respiratory tract; pipe and cigarsmoking cause cancers in the mouth and upper respiratory tract;

tobacco chewing causes cancers of the gums, lips and jaw, ticularly where the wad of soggy tobacco rests between the gumsand tongue

par-(Note: cancers outside the respiratory tract are similar in smokersand non-smokers; thus, smokers are not simply less healthy.)Carbon monoxide This combines with haemoglobin in the blood, reducing its oxygen

carrying capacity; this leads to oxygen deficiency in all cellssupplied by narrow blood capillaries: toes and feet resulting incell death, gangrene and limb amputation (Reynaud’s syndrome);

legs resulting in arteriosclerosis, leg pains and limb amputation(Reynaud’s syndrome); skin resulting in skin wrinkling andpremature ageing; penis resulting in reduced blood supply, erectiledysfunction and premature impotence; heart resulting in manydifferent forms of cardiac disorder, arteriosclerosis, heart attack,exacerbation of cardiac problems caused by other factors (hyper-tension, diabetes) and reduced success for cardiac surgery; fetusresulting in more prenatal, perinatal and postnatal problems, morestillbirths, birth difficulties and underweight live births

Nicotine Few direct health effects; chronic increase in heart rate may

exacerbate cardiac hypertension; highly addictive, causing creased stress and depression (see text)

in-Passive smoking Non-smokers who breathe air polluted by tobacco smoke can

develop the same disorders as smokers: lung cancer, pulmonarydiseases, asthmatic attacks, increased rates of pneumonia andbronchitis in children, more debilitating coughs and colds, childrenspend more time off-school and infant cot deaths (SIDS)

Health benefits of cessation Lung function improves almost immediately, with aerobic tasks

becoming easier; oxygen supply to all tissues improves rapidly,with reduced leg pains and better cardiac functioning; the incidence

of heart attack is reduced by 50% within 1 year; respiratorycancers reduce more gradually, with lung cancer rates returningnearer to those of non-smokers within 15 years; and significantlyreduced stress 3–6 months after quitting

Based on Parrott (1998a).

Passive smoking

When a non-smoker breathes in air polluted by tobacco smoke, nicotine enters theirblood circulation, carbon monoxide combines with haemoglobin and the cancerous tarssettle on their lungs and respiratory tract It has been estimated that when a non-smoker works in a smoky office for eight hours, it is equivalent to actively smoking1–2 cigarettes In enclosed atmospheres, such as cars with closed windows, submarines

or aircraft cabins, the cumulative effects are even more marked; this explains whypassive smokers often develop the same tobacco-related diseases as active smokers.One of the first studies to empirically demonstrate this was undertaken in Japan,where cigarette smoking was predominantly a male activity Hirayama (1981) investi-gated the incidence of lung cancers in non-smoking females and found a doubled cancerrate in those women whose husbands smoked tobacco Numerous further studies haveconfirmed the adverse health effects of passive smoking (NIH, 1993) Passive smokingcauses lung cancer, respiratory coughs, reduced lung capacity, middle ear infection,pneumonia and bronchitis Around 3,000 lung cancers in non-smokers are caused byenvironmental tobacco smoke each year in the USA (NIH, 1993), which extrapolates toaround 1,000 lung cancer deaths/year in British non-smokers (Parrott, 1998a) Thesefindings necessitate a re-examination of the health data for the non-smokers in Doll andPeto (1976) They found very low rates of lung cancers in non-smoking doctors, butmany of these were caused by passive smoking; thus, the adverse health effects ofsmoking are even worse than originally described Asthma is also exacerbated bypassive smoking, with many children having asthmatic attacks induced by passivesmoking (NIH, 1993) Research from New Zealand and many other countries hasfound that passive smoking is a major cause of cot death in children below the age

of one (sudden infant death syndrome, or SIDS, in the USA) Parents are now routinelyadvised never to smoke anywhere near their young children, and when this advice isfollowed it leads to a significant decrease in these deaths

Nicotine absorption and smoking behaviours

Smoking is a rather odd behaviour Why should anyone willingly inhale noxious smokethat irritates the lungs and induces coughing? The answer is that smoke inhalation is anextremely rapid and efficient route for drug delivery (Chapter 3) The lungs are designed

to readily absorb oxygen, but the fine network of surface blood capillaries allows them

to take up other small chemicals also present in the air Earlier it was noted thatnicotine is present on the tar droplets of tobacco smoke When this smoke settles onthe lungs some of this nicotine is absorbed Thus, smoke inhalation generates a bolus,

or hit, of nicotine, which reaches the brain 7–10 seconds later Smoking is effective forthe self-administration of many psychoactive drugs: cannabis (Chapter 7), opiates(Chapter 8) and some central nervous system (CNS) stimulants (Chapter 4) Thetobacco in a single cigarette contains 50–60 mg of nicotine If this were extracted andinjected, then it would be sufficient to kill any individual through cardiac and respira-tory failure (Leonard, 1997) However, most of the nicotine in the leaves is combusted,

so that only 0.5–2.0 mg is present in the inhaled smoke and around 0.1–0.4 mg nicotine

is then absorbed by the lungs

Smokers titrate their nicotine administration in subtle but habitual ways The

initial inhalation of the first cigarette of the day is generally quite deep, with the

smoke being retained deep in the lungs for several seconds; this provides a substantial

bolus of nicotine, which helps to reverse the state of overnight nicotine depletion; this is

why most smokers state that the first cigarette of the day is the most satisfying

Successive draws tend to be shallower and more widely spaced, as the smoker

self-titrates increasingly smaller amounts of nicotine When two cigarettes are smoked in

quick succession, inhalations on the second cigarette tend to be shallower and more

widely spaced; it may even be extinguished before it is finished But when a regular

smoker experiences a prolonged period without smoking (2–3 hours), their inhalations

on the next cigarette again tend to be quite deep, as they self-administer more

sub-stantial amounts of nicotine to reverse the temporary abstinence effects Therefore,

there is a direct linear relationship between the inter-cigarette interval and the degree

of satisfaction provided by each cigarette (Fant et al., 1995) When cigarettes are

smoked in quick succession they have little measurable effect and are being smoked

to forestall abstinence symptoms from developing; this also occurs in smokers who are

about to enter prolonged no-smoking situations, when they preload with nicotine

beforehand

Pharmacological effects of nicotine

Nicotine binds to nicotinic acetylcholine receptors, which are widely distributed

throughout the peripheral nervous system (PNS) and the CNS In the PNS, nicotine

affects both the parasympathetic and sympathetic nervous systems (Chapter 2)

However, sympathomimetic changes predominate, although why this occurs is not

clear In regular smokers, nicotine increases resting heart rate by 10–30 beats per

minute (b.p.m.) with the first cigarette of the day Over a day of unrestrained

smoking, the resting heart rate of a regular smoker is around 10 b.p.m higher than

that of non-smokers One of the few adverse health effects of nicotine itself is therefore

an exacerbation of hypertension and cardiac distress (Table 4.1)

In the CNS, the effects of nicotine on acetylcholine receptors are extremely

complex Despite the large amount of pharmacological research, no clear or simple

explanatory model for its neurochemical effects has emerged Zevin et al (1998, p 44)

have described some of the complexities of nicotine pharmacokinetics and

pharmacody-namics: ‘‘There is a multitude of different subtypes of neuronal nicotine receptors

Different nicotinic receptors are found in different brain regions and have different

agonist-binding affinities and different electrophysiological responses to stimulation

(Karlin, 1993; McGehee and Role, 1995); this may explain the diversity of effects of

nicotine in the body.’’ The effects of nicotine on the many different nicotinic ACh

receptor systems can change and alter in complex ways The initial effects of nicotine

are to open ion channels and, thus, activate the neuron However, its continued presence

then leads to a deactivated or desensitised state when the ionic channels close The dose

response effects of nicotine are also complex, with low and high doses producing

opposite effects The regular use of nicotine also leads to an increased number ofnicotinic receptors, a phenomenon not predicted with a receptor agonist, sincereceptor down-regulation generally occurs Finally, nicotine receptor activationresults in the release of many other neurotransmitters including dopamine, noradren-aline, glutamate and serotonin, in addition to acetylcholine (Zevin et al., 1998; Karlin,1993; McGehee and Role, 1995) These complexities make nicotine one of the mostconfusing of all psychoactive drugs to model in neurobehavioural terms In most under-graduate drugs and behaviour textbooks, nicotine is only covered briefly and rarely areits complexities fully described Furthermore, it is sometimes categorised as a stimulant,

in others as a relaxant, although most describe its psychopharmacological effects ascontradictory (Grilly, 2001)

Psychological effects of nicotine

When tobacco smokers are asked why they smoke, they often have difficulty in giving aclear reason Many smokers state that that they find it satisfying and crave a cigarette ifthey have not smoked recently, but it is generally unclear what this craving actuallymeans Various mood states are affected by smoking: stress/relaxation, irritation/pleasure and alertness/concentration The exact nature of these mood changes is alsodifficult to summarise Around 80–90% of smokers state that smoking helps them tocope with stress, but, paradoxically, they fail to demonstrate clear evidence for genuinerelaxation: for instance, taking up smoking during adolescence prospectively leads toincreased feelings of daily stress (note: the reasons for this conundrum are debatedbelow) Similar problems surround the data on smoking and pleasure Althoughmany smokers state that cigarettes provide feelings of relief and satisfaction, theyreport only normal/average self-ratings of pleasure when replete with nicotine andsuffer from heightened feelings of anger, irritability and annoyance when deprived ofnicotine Thus, it is difficult to find any empirical evidence for a genuine increase inpleasure after smoking

Another reason given by many smokers is that cigarettes help with work andconcentration, especially when having to perform long and boring tasks, such asradar tracking or long-distance driving There is also an extensive body of empiricaldata, demonstrating that smokers are better at cognitive tasks when they smoke thanwhen they are not smoking (Wesnes and Parrott, 1992; Heishman et al., 1994).However, closer inspection of these data again raises serious questions about whetherthis indicates true cognitive gains In a classic series of studies, Wesnes and Warburton(1983) investigated the effects of different strength cigarettes and different doses of oralnicotine on performance in the rapid visual information processing (RVIP) task, asensitive measure of cognitive vigilance The standard procedure involved assessingovernight nicotine-deprived smokers (þ12 hours’ abstinence), in order to obtainbaseline values Then, they were given cigarettes of different strengths to smoke (low

or high nicotine), while in other studies they were administered nicotine or placebo oraltablets Mid to high nicotine conditions led to better vigilance performance than low,zero or high nicotine conditions Furthermore, significant performance improvementscould be demonstrated after just two inhalations from the first cigarette of the day

(Revell, 1988) These studies were interpreted as showing that nicotine was a cognitive

enhancer, boosting alertness through an increase in cholinergic activity (Parrott and

Winder, 1989; Revell, 1988; Wesnes and Warburton, 1983; Wesnes and Parrott, 1992)

One methodological weakness with the above studies was the absence of a

non-smoking control group; this is crucial since, without control data, it is unclear whether

smokers’ performance is impaired during abstinence and restored by smoking or

normal during abstinence and boosted by nicotine/smoking When non-smoking

controls are used the cognitive performance of the active smokers is generally similar

to that of the non-smokers Ashton et al (1972) tested smokers and non-smokers on a

driving simulator and showed that the overall performance levels for the two groups

were very similar, although, when physically smoking, the performance of the smokers

was significantly more variable, suggesting that looking for and picking up the cigarette

may have interfered with attention toward the simulator Subsequent studies have

generally confirmed that non-deprived smokers generally show similar cognitive task

performance to non-smokers; although a few have found better performance in

smokers and a few have found better cognitive performance in non-smokers (for

reviews see Heishman et al., 1994 and Wesnes and Parrott, 1992) Overall, therefore,

there is very little empirical evidence to suggest that smokers benefit from cognitive

gains; this was confirmed by Herbert et al (2001), who found that, when non-deprived

smokers had a cigarette, RVIP task performance remained completely unchanged This

suggests that the earlier findings of vigilance task gains, when overnight

nicotine-deprived smokers were given nicotine/cigarettes, may reflect the reversal of

abstinence effects (Revell, 1988; Wesnes and Warburton, 1983) Thus, an understanding

of nicotine abstinence seems to be crucial for an explanation of these mood and

cognitive effects

Nicotine abstinence

When regular smokers are deprived of nicotine they typically report a range of negative

feelings: irritability, tenseness, anxiety, depression and poor concentration (Hughes et

al., 1990) Furthermore, when assessed on object performance tasks, their ability level is

typically below that of either non-smokers or non-deprived smokers: on laboratory

vigilance tasks, deprived smokers miss more targets; on reaction time tasks, their

responses tend to be slower and more variable; and on memory tasks, they often

forget more information (Heishman et al., 1994; Wesnes and Parrott, 1992) These

psychobiological impairments mean that temporarily deprived smokers suffer from a

range of everyday problems, so that, when regular smokers agreed to abstain from

cigarettes for a day, in the evening they reported having experienced more hassles,

less uplifts and more cognitive failures (Figure 5.1) Their day without nicotine also

led to a range of mood deficits, with significantly greater stress, less pleasure and lower

arousal/alertness (Parrott and Kaye, 1999) The non-deprived smokers were similar to

non-smokers, confirming that nicotine does not provide smokers with any

psycho-logical advantages (Parrott and Garnham, 1998; Parrott and Kaye, 1999; Figure 5.1)

This raises the question of how rapidly these abstinence effects take to develop In

one study, deprived smokers were found to be worse than continuing smokers after 2–4

hours of abstinence, with higher irritability and depression, worse feelings of tration and poorer cognitive task performance (Parrott et al., 1996) However, signifi-cant mood and cognitive deficits have also been demonstrated after just 1 hour ofabstinence (Parrott et al., 2000) This timescale agrees with everyday patterns ofcigarette use, since moderate to heavy smokers tend to light up a new cigarette every30–60 minutes In a naturalistic study of 105 smokers, self-rated mood states wererecorded before and after every cigarette over a day of normal smoking (Parrott,1994) Most smokers reported fluctuating mood states over the day, with below-average moods before lighting up, followed by normal/average moods immediatelyafter each cigarette The most heavily dependent smokers experienced the strongestmood vacillations over the day (Figure 5.2) They reported the highest stress andlowest alertness in-between cigarettes, followed by the greatest amount of moodnormalisation, with each cigarette restoring their moods to average/normal values(Parrott, 1994, 2003).

concen-Nicotine dependence: a direct cause of

psychological distress

Therefore, smokers feel normal when replete with nicotine, but suffer from unpleasantabstinence symptoms when deprived of nicotine (Parrott, 1994, 1999, 2003; Parrott etal., 1996; Parrott and Garnham, 1998); this is why the strongest satisfaction ratings aregiven to cigarettes smoked after an extended period without nicotine (Fant et al., 1995).However, the repetitive experience of abstinence symptoms in-between cigarettes causessmokers to suffer from increased distress over the day Nicotine dependence is therefore

a direct psychobiological cause of stress; this explains why youngsters who take upsmoking report increasing stress and depression in later years Johnson et al (2000)assessed several hundred Americans over on two occasions six years apart Smokingwhen aged 16 led to an increase in generalised anxiety when 22 years old, whereas high

Figure 5.1 Psychobiological functions and well-being over the day, as self-rated by non-smokers,non-deprived smokers and abstaining smokers

Based on Parrott and Kaye (1999).

anxiety at 16 did not lead to an increased incidence of later smoking Smoking led to

increased stress, whereas stress did not lead to smoking McGhee et al (2000)

monitored the mental health, behavioural problems and drug use of 900 New

Zealand youngsters aged 15, 18 and 21 Those adolescents who were regular smokers

at 18 reported a significant increase in anxiety and depression 3 years later Similar

increases have been shown for panic attacks (Breslau et al., 1998), and depression (Wu

and Anthony, 1999; Breslau et al., 1998; Goodman and Capitman, 2000) Some of these

prospective studies also found that the most disadvantaged youngsters were at greatest

risk from becoming smokers However, cigarette smoking never led to psychobiological

gains; instead, the reverse occurred, with the uptake of smoking leading to an increased

incidence of stress, depression or panic attack in later years

This also explains why quitting smoking leads to psychobiological gains Several

prospective studies have found that when adults quit smoking they report significantly

lower levels of stress 6 months later (Cohen and Lichtenstein, 1990; Parrott, 1995)

Self-rated feelings of depression also reduce in smokers who manage to successfully quit

(Hughes, 1992) The data are thus clear and consistent: nicotine dependence causes

increased stress (Parrott, 1999), greater depression and other psychobiological

problems (Parrott, 2003)

Figure 5.2 Feelings of stress and arousal over a day in a regular cigarette smoker Moods were

self-rated immediately prior to each cigarette, then again immediately afterward Thus, each

arrow represents the mood effects of one cigarette Dotted lines show the mood changes

in-between cigarettes

Reproduced from Parrott (1994).

Heavy nicotine use versus light/occasional smoking

Around 80–85% of cigarette users are nicotine-dependent, following a fairly standardpattern of smoking Their cigarettes are spaced over the day, often in close conjunctionwith routine situations: meals and work breaks They represent the classic nicotine-dependent smoker, the main focus for discussion so far (Figure 5.2) However, there areother patterns of tobacco/nicotine use ranging from very heavy to very light The mostintense nicotine use is shown by the shamans or spiritual leaders in some SouthAmerican tribes They smoke chillums (thick pipes) full of tobacco, inhaling amounts

of nicotine that would be lethal for any untrained initiate; this generates a trance-likestate involving intense visions, which are intrinsic to their religious rituals Eachshaman is trained for this intense smoking from an early age, since they need tobuild up tolerance to the large amounts of nicotine involved The other members ofthe tribe never use tobacco, so that when the first cigarette-smoking Western anthro-pologists were seen, they were treated with great reverence Among Western smokers,the highest rates of nicotine consumption are found with chain smokers, when each newcigarette is lit from the stub of the previous one Chain smokers may consume 60–80cigarettes every day, with more or less continuous nicotine inhalation during the wakinghours Brown (1973) found that these very heavy smokers had electroencephalographs(EEGs) indicative of heightened arousal Continuous nicotine intake can thereforeincrease arousal, but only when there are few periods of abstinence, since arousalwould then start to decline

At the opposite end of the spectrum there are light, or occasional, smokers whomShiffman (1989) described as ‘‘chippers’’ They may go for several days without acigarette, but then smoke intensively in social situations, such as parties They aregenerally influenced by the social group and setting, smoking heavily when withother smokers but content not to smoke with non-smokers Occasionally, they maysmoke on their own Around 10–15% of adult smokers fit this pattern, although it ismore characteristic of young novice smokers One explanatory model suggests that thisrepresents the early stages of nicotine dependence, with occasional smokers graduallymoving toward higher rates of tobacco consumption as they develop stronger nicotinedependence However, that does not explain why a minority of smokers continue tomaintain occasional use for many years One intriguing finding by Shiffman (1989) wasthat chippers report few mood changes when smoking and do not experience mooddecrements during abstinence Thus, it may be the lack of abstinence symptoms, accom-panied by the absence of mood normalisation when smoking, which explains how a fewindividuals maintain occasional patterns of drug use

Occasional smokers display many of the non-pharmacological factors thataccompany cigarette use Thus, they often state that they feel and look attractivewhen smoking This factor has reduced in importance in a few societies (the USA,the UK, Australia, New Zealand), but in most countries cigarettes are still associatedwith maturity and affluence, particularly among adolescents Tobacco advertising isimportant for maintaining this belief The sensory, cognitive and psychomotorcomponents of smoking can also be pleasurable: spending money, breaking open thenew packet, lighting up and the sensorimotor manipulations of fingers and lips.Hollywood films are also important, with smoking generally portrayed as sexy and

pleasurable, rather than addictive and problematical Indeed, the film industry often

accepts tobacco company sponsorship for product placement Smokers are thus

bombarded by positive advertising images for smoking, which is why funding for

accurate health information is so important Russell et al (1974) developed the

smoking motivation questionnaire to measure the different factors associated with

tobacco; several primary factors emerged, which factorised into two broad groups of

pharmacological and non-pharmacological factors The pharmacological factors

included: dependence and addiction, automatic or unconscious smoking, the relief of

anger and stress and the maintenance of alertness The non-pharmacological factors

comprised: psychological image (looking good) and sensorimotor aspects (having

something to do with your hands) These non-pharmacological aspects typify the

motives reported by occasional smokers, while dependent smokers score heavily on

the pharmacological/dependence factors

Smoking initiation

Most adult smokers had their first cigarette between the ages of 10 and 15 So, if a

youngster can avoid experimentation before the age of 16, they are unlikely to become a

smoker (USA Department of Health, 1994) One of the main influences on childhood

smoking is the peer, or conformity, group, with slightly older siblings being particularly

influential Younger children imitate their older sisters/brothers and then become key

figures of influence among their own age group Peer pressure is often important, when

group members are expected to conform and experiment with the new forbidden

activity However, peer selection is also important, with many children changing

group allegiances Those group members who do not wish to conform gravitate

toward other subgroups whose views are consistent with their own (Ferguson et al.,

1995) Those factors that increase rates of smoking uptake include parental smoking,

low socio-economic status, poor self-image and exposure to cigarette advertising

Factors that contribute toward low smoking rates include higher tobacco taxes,

enforcement of laws to reduce under-age purchase and school-based anti-smoking

programmes The most successful school-based packages are comprehensive and

well-constructed, student-centred rather than lecture-based and are given regularly as

part of a systematic programme However, even the most effective programmes lose

their influence once they have ended (USA Department of Health, 1994) Finally, future

programmes should include data on the adverse psychological effects of nicotine

dependence Many youngsters believe that smoking can help relieve stress They need

to be find out why this belief is incorrect and work out how smoking actually increases

stress and depression

Smoking cessation

Around half of American and British adults who used to smoke have now stopped

Furthermore, 80–85% of current smokers state that they would like to quit and wish

they had never started However, quitting can be difficult, with many smokers relapsing

after a short period Various commercial stop smoking packages are available andgenerally claim high rates of success, but their optimistic calculations are often quitemisleading They are often based on short-term data (stopping for a few weeks),abstinence is indicated by self-reports (notoriously inaccurate) and misleading calcula-tions are used to generate the impressively high success rates (e.g., exclusion of anyparticipant who fails to complete the programme) To estimate genuine cessation, fartougher criteria need to be employed: inclusion of everyone who commences thepackage, abstinence for 6–12 months and regular biochemical confirmation ofnon-smoking via plasma cotinine or expired breath carbon monoxide measurements.Viswesvaran and Schmidt (1992) undertook a meta-analysis of 633 published studiesthat met these criteria, involving around 70,000 participants The control subjectsreported an annual quit rate of around 6%, but this improved slightly to 7% inthose who had been advised by their physician to quit More detailed cessationpackages involving information on the adverse health effects coupled with basic coun-selling led to 17% cessation rates But the most impressive rates were found in multi-component programmes; here, abstinence rates of 30–40% were achieved when nicotinesubstitution was combined with social skills training.

The reason these packages were most successful was that they tackled bothaspects of cigarette use: pharmacological and non-pharmacological Nicotine substi-tution can help relieve abstinence symptoms, and social skills training can help theindividual to relearn how to live without continually reaching for a cigarette Severalcontrolled nicotine delivery systems are available: nicotine gum, transdermal patchesand nicotine inhalers By delivering controlled amounts of nicotine, they can helprelieve nicotine withdrawal symptoms In double-blind, placebo-controlled trials, theyhave each been shown to significantly improve quit rates, generally doubling the successachieved under placebo (Viswesvaran and Schmidt, 1992) However, on their own,nicotine substitution devices are still only marginally successful: for instance, thenicotine patch leads to a 10% annual quit rate, compared with the placebo patchwith around 5% success (Stapleton et al., 1995) Smokers need advice and assistance

to enable them to handle the numerous social pressures for relapsing: the skill of saying

‘‘no’’ when desperately wanting to say ‘‘yes’’; the recognition and avoidance of highrelapse situations, especially those where they used to smoke; the support gained whenquitting with a friend (note: if the partner remains a smoker, relapse rates are extremelyhigh) Most smokers also need to develop far more knowledge about the adverse healtheffects Passively listening to a lecture often has limited impact; it is much more useful toactively investigate the topic, possibly as a group project Knowledge acquisition ismost effective when it is an active process, resulting in more elaborate and robustcognitive structures, which have thus far been found to be useful when faced withthe temptation to relapse

Many smokers recognise that the first few days of quitting will be very difficultand, indeed, many return to smoking within a short period However, many abstain formonths or years, but still relapse again The American Surgeon General (1990) notedthat 15% of former smokers still return to smoking after abstaining for two or moreyears Therefore, quitting smokers need to be informed about the dangers of relapse.There are various situations where susceptibility to relapse is greatest, particularlyperiods of increased stress, such as bereavement or divorce; the same is true of anysituation involving alcohol, since it reduces inhibitions and heightens misbeliefs, such as

‘‘I can handle just one cigarette’’ Nicotine and alcohol also have opposing

psycho-biological profiles, with alcohol reducing arousal and nicotine partially reversing this

Thus, around 90% of heavy drinkers/alcoholics are heavy smokers When quitting

smokers do relapse how should they respond to this setback? Many smokers believe

that it proves their nicotine addiction, they are failures and might just as well carry on

smoking Marlatt (1996) has termed this the abstinence violation effect and counsels

those who relapse on how to learn from the experience They should examine why they

relapsed and how they might handle high-risk situations more effectively in the future

Most importantly, it does not mean that they have to take up smoking again Since they

were successful for a period, they can be successful again The evidence confirms that

most former smokers have a few relapse periods before they stop permanently

Nicotine: a powerful drug of addiction

Nicotine is certainly one of the most powerful drugs of addiction Sigmund Freud used

cocaine and nicotine and, although he managed to stop using cocaine, he was unable to

stop smoking He developed cancer of the jaw, which gradually killed him over a long

and painful period Despite numerous attempts at quitting and various surgical

inter-ventions on his cancerous jaw, he remained a smoker until his death Opiate users often

state that withdrawing from heroin was easier that quitting smoking; group data on

cessation rates generally confirms this In relation to initial drug uptake, many who

experiment with cocaine or amphetamine do not develop stimulant dependence, while

moderate non-dependent alcohol use is the norm In contrast, most youngsters who

occasionally smoke during early adolescence become regular smokers McNeill et al

(1987) studied the smoking behaviour pattern of young adolescent female smokers at

school and found that many had attempted to quit smoking but failed, with nicotine

dependence already evident in some 13–15-year olds

One crucial difference between nicotine and other addictive drugs is the

psycho-biological state of the individual when on drugs Opiate users, stimulant abusers,

cannabis smokers and alcohol drinkers become abnormal when replete with drug

Thus, they describe themselves as being ‘‘stoned’’, ‘‘high’’ or ‘‘spaced out’’ (Chapters

5–9) In contrast, tobacco smokers are almost normal when replete with nicotine, so

that in psychobiological terms active smokers are similar to non-smokers (Figures 5.1

and 5.2); this is why the motives for cigarette craving can be so difficult to describe

How can a heavy smoker explain their overpowering need for a cigarette – when it is

taken just to feel normal? The continual use of nicotine/tobacco to maintain normal

feelings also becomes strongly conditioned over time A heavy smoker inhales tobacco

smoke 70,000 times each year, with each inhalation generating another nicotine hit,

which is why it can become such a difficult habit to quit Cigarettes are also associated

with pleasurable personal activities and social events: after meals, during tea/coffee

breaks, visits to taverns and public drinking houses, social functions and celebrations

and after sex The close association with this vast array of everyday activities, coupled

with the need for nicotine to remain feeling normal, helps explain why nicotine is so

strongly addictive Indeed, it would be difficult to design a more powerful drug of

addiction

1 The World Heath Organisation has stated that cigarette smoking is the singlemost preventable cause of death in the world Explain why breathing in tobaccosmoke is so lethal

2 Why is it dangerous for non-smoking adults and children to breathe in airpolluted by cigarette smoke?

3 Oscar Wilde stated in 1891 that: ‘‘A cigarette is the perfect type of a perfectpleasure It is exquisite, and it leaves one unsatisfied.’’ Has modern psychophar-macological research confirmed this description?

4 Many smokers believe that nicotine/cigarettes help them to cope with stress, butare they correct in this belief ?

5 Grilly (2001) noted that: ‘‘Despite the numerous studies on tobacco use, it is stillnot clear what is so reinforcing about the practice.’’ Do you agree or can yououtline an explanatory model?

6 Why do adolescents who take up smoking soon report increased levels of dailystress and depression?

7 What practical advice would you give someone who wanted to quit smoking?

8 Design a health promotion package that explained the psychological processesunderlying tobacco smoking and the psychological gains that follow cessation

Key references and reading

Goodman E and Capitman J (2000) Depressive symptoms and cigarette smoking among teens.Pediatrics, 196, 748–755

Parrott AC (1998a) Social drugs: effects upon health In: M Pitts and K Phillips (eds), ThePsychology of Health (2nd edn) Routledge, London

Parrott AC (1998b) Nesbitt’s Paradox resolved? Stress and arousal modulation during cigarettesmoking Addiction, 93, 27–39

Parrott AC (1999) Does cigarette smoking cause stress? American Psychologist, 54, 817–820.Parrott AC (2003) Cigarette derived nicotine is not a medicine World Journal of BiologicalPsychiatry, 4, 49–55

Shiffman S (1989) Tobacco ‘‘chippers’’: Individual differences in tobacco dependence pharmacology, 97, 539–547