Transcript A2 Addiction

Addiction
Biological models
The genetics of addiction
Family and twin studies
Agrawal and Lynskey (2006) – illicit drug
abuse and dependence affected by genetic
influences, heritability estimates between
45% and 79%
Kendler et al. (2003) common genetic factor
influences alcohol abuse, drug abuse and
dependence, and adult antisocial behaviour
Specific genes, specific drugs
Kendler and Prescott, (1998)
Variant of the D2 receptor gene DRD2 in ⅔
deceased alcoholics compared to only ⅕ of
deceased non-alcoholics (Noble et al., 1991).
Individuals with this A1 variant have fewer
dopamine receptors in pleasure centres in
brain, hence become addicted to drugs that
increase levels of dopamine.
Biological models
The genetics of addiction
Inconsistent research findings
Individual differences
Genetic explanations can
explain why some people
become addicted yet
others with same
experiences do not using
diathesis-stress model.
Meta-analysis by Noble (1998) –
48% of severe alcoholics, 32% of less
severe alcoholics and only 16% of
controls had A1 variant of the DRD2
gene. However, subsequent studies
have found no relationship or no
relationship between this variant
and addiction to alcohol.
DRD2 and Tourettes
A1 variant also occurs with
several other disorders
including Tourettes (45% of
cases). Creates a problem
for idea of DRD2 being a
‘reward’ gene.
Biological models
The genetics of addiction
Tatum O’Neill, was
arrested in New York for
trying to buy cocaine (she
eventually pleaded guilty
to disorderly conduct).
“Addiction runs in
families. It’s a disease,”
she said.
Biological models
Dopamine and addiction
INITIATION
RELAPSE
Drug-taking triggers the
release of dopamine.
Mesolimbic pathway in the
brain creates memories
that link drugs such as
cocaine to the rewarding
nature of their activation
of dopamine receptors.
Permanent recovery made
difficult because of druginduced changes that
create lasting memories of
the drug. This is made even
more difficult by reminders
of the drug and the promise
of imminent reward.
MAINTENANCE
Chronic exposure to drugs results in
a reduction of these reward circuits.
This creates withdrawal symptoms
so user must now take higher doses
of the drugs to avoid this unpleasant
state (negative reinforcement).
Biological models
Dopamine and addiction
Supporting evidence
Social stress and dopamine
Volkow et al. (2001) gave adults Ritalin
which raises dopamine levels. Some
loved the feeling and some hated it.
Those who loved it had fewer
dopamine receptors than those who
hated it. Explains why some people,
after experimenting with drugs
become addicted and others don’t.
Research with monkeys (Grant et
al., 1998) showed that dopamine
system can be influenced by social
interaction. Animals that lost
social status also lost dopamine
receptors. Suggests that stress of
poverty makes some people more
vulnerable to addiction.
Limitation
This explanation
ignores the social
context of drug
taking although it
does allow for
treatment
IDA
Synoptic issues
Cognitive models
Self-medication
Initiation
This proposes that individuals
intentionally use drugs to ‘treat’
psychological symptoms (e.g.
loneliness, depression) from which
they suffer. The choice of drug depends
on the effect the individual desires.
Maintenance and relapse
‘Stress relief’ often cited as reason why people
smoke. However, smokers report higher levels of
stress. When they stop, stress levels decrease,
only to rise again when smoking again.
Each cigarette has an immediate effect on
decreasing withdrawal symptoms but ongoing
smoking increases stress levels once more.
Cognitive models
Self-medication
Research support
Gottdiener et al. (2008) – meta-analysis to test
assumption that substance abuse is due to a
failure of ego control, i.e. the inability to
control the impulse to self-medicate.
Participants with substance abuse disorders
showed significantly lower levels of ego
control than control group of non-alcoholics.
Problems of cause and effect
Self-medication model predicts that distress
must precede need for self-medication.
Supported by research with sexually abused
women who used alcohol to remove resulting
sexual inhibitions (Sanjuan et al., 2009), but
other studies have found no preceding distress
prior to self-medication.
Cognitive models
Expectancy theory
Initiation
Drug or alcohol use escalates into addiction as a result of the
expectations that an individual has about the costs and benefits
of that activity.
Among heavy drinkers, drinking has been shown to be
associated with expectations of social and physical pleasure,
tension reduction, enhanced cognitive and motor performance
and greater sociability (Brown, 1985).
Maintenance and relapse
As an addiction develops, it is maintained less by
conscious expectations and more by unconscious
expectations involving automatic processing.
This explains the loss of control that many addicts
report concerning their addictive behaviour and the
difficulties they face in abstaining.
Cognitive models
Expectancy theory
Subjective evaluation
Most research measures the
likelihood of experiencing
certain effects, but Leigh
(1987) suggests subjective
evaluation of outcomes
more important determinant
of drinking behaviour.
Addiction or consumption?
Few studies distinguish
between ‘problematic
behaviour’ such as bingedrinking or drug-taking and
addictive (involving loss of
control) behaviour.
Synoptic issues
IDA
Learning models
Operant conditioning
Initiation and positive reinforcement
Behaviours that lead to consequences
that the individual finds rewarding are
likely to be repeated.
Crack cocaine produces massive
activation of dopamine receptors in
mesolimbic system which is rewarding.
Maintenance and relapse
After repeated exposure to drug,
withdrawal symptoms develop which
are the body’s compensatory reactions.
Taking the drug is now necessary to
avoid these unpleasant sensations, an
example of negative reinforcement.
Learning models
Operant conditioning
Strengths of explanation
Can explain how process of addiction develops and is
maintained without conscious choice or awareness and
why addicts experience conflict when they try to abstain.
Also explains why many addicts report a decrease in other
drives such as eating. Addiction creates drives that are
hard to satisfy therefore take priority over other drives.
Problems of explanation
There are aspects of addiction that are not explained by
this explanation. Robinson and Berridge (1993) point out
that many people take potentially addictive drugs at some
times in their lives yet relatively few become addicts.
This suggests that there are other psychological and
physiological factors are involved in the transition from
consumption to addiction.
Learning models
Classical conditioning
Initiation and secondary reinforcers
Stimuli that precede or occur at the same time as a
learned stimulus become secondary reinforcers,
deriving their influence by association. To an
alcoholic, sights and sounds of a pub elicit same
physiological responses (e.g. arousal) as alcohol
itself. To a heroin addict, the drug paraphernalia
(syringe, lighter, teaspoon) has the same effect.
Drug
effect
Bodily response
Drug
effect
Bodily response
No response
Bodily response
Maintenance and relapse
Drug habit is maintained through threat of
withdrawal symptoms. Drug effect is now UCS,
body’s response as it tries to restore equilibrium
is the UCR. Stimuli that precede the drug dose
become CS. If presented alone, CS causes CR
but this creates disequilibrium if no drug dose.
Learning models
Classical conditioning
Research support
Implications for treatment
Major claim is that stimuli that occur at same
Drummond et al. (1990) propose the use of
cue exposure (presenting cues without
opportunity to engage in drug-taking. This
leads to stimulus discrimination, as without
the reinforcement of the actual drug, the
association between cue and drug is
extinguished, reducing the cravings.
time produce same response. Evidence in
support of this prediction from study of
soldiers returning from Vietnam who were
less likely to relapse because sights and
sounds associated with their drug-taking
were now different.
Synoptic issues
IDA
Smoking addiction
Starting smoking
Effects of nicotine
Smoking initially symbolic
act conveying messages
such as ‘I’m tough’ or ‘I’m
rebellious’. Desired image
sufficiently powerful to put
up with unpleasantness of
smoking until physical
effects take over.
Nicotine activates
receptors in the brain
which leads to the release
of dopamine. This creates
feelings of pleasure for,
but is short-lived and
must be repeated to avoid
withdrawal symptoms.
Socioeconomic status and addiction
Research suggests an association between
addiction to nicotine and social
disadvantage (Fidler et al., 2008), which
would explain why poorer smokers find it
difficult to quit (they have a higher nicotine
intake).
Smoking addiction
Socioeconomic status
Link between socioeconomic
status and nicotine intake
supported in French study with
poor housing conditions linked
to greater nicotine intake.
Suggests that interventions
must also attempt to improve
poor smokers’ living conditions
to lower incidence of smoking.
Smoking and popularity
Peer popularity and smoking
link supported in study which
found positive relationship
between smoking at age 16
and boys’ popularity two years
later (Mayeux et al., 2008).
This was not the case for other
risky behaviours such as the
use of alcohol and sexual
activity at age 16.
Effects of nicotine
Khaled et al., (2009) study
supports possibility that longterm smoking has adverse effect
on mood. Incidence of depression
was highest among smokers and
lowest among ‘never smoked’.
Gambling addiction
Genetic factors
Pathological gambling
appears to run in families.
Twin study (Shah et al.,
2005), using adult
participants found
evidence of genetic
transmission of gambling
among men.
Black et al. (2006) found
first degree relatives of
pathological gamblers
were more likely to suffer
from pathological
gambling than were more
distant relatives
Sensation seeking and
boredom avoidance
Zuckerman (1979) –
individual differences in
need for optimal amounts of
stimulation. High sensation
seekers have lower
appreciation of risk and
anticipate arousal as more
positive than do low
sensation seekers.
Blaszczynski et al. (1990) –
pathological gamblers had
higher boredom proneness
scores than control group of
non-gamblers.
Gambling addiction
Genetics or environment?
Difficult to disentangle the
relative influences of genetics
and environment, but Slutske
et al., (2000) estimates that
64% of the variation in risk for
pathological gambling can be
accounted for in terms of
genetic factors alone.
What is inherited?
A genetic predisposition for gambling may work
indirectly through the trait of impulsivity.
A number of studies have found supporting
evidence for this relationship, i.e. that impulsivity as
an inherited trait is a significant predictor of the
development of pathological gambling.
Lack of research support
The claim that gamblers should be
higher sensation seekers appears to be
true for casino gamblers but not for
gamblers who bet on horse racing in a
betting shop (Coventry and Brown,
1993). This challenges the view of
gambling as a homogenous activity.
Synoptic issues
IDA
THEORY OF REASONED ACTION
THEORY OF REASONED ACTION
Attitude
An individual's positive or negative feeling associated with
performing a specific behaviour. They will hold a favourable
attitude toward a behaviour if they believe that the performance of
the behaviour will lead to mostly positive outcomes.
Subjective Norm (plus descriptive norm)
Determined by an individual's normative beliefs that significant
others think they should or should not perform the behaviour, plus
motivation to comply with these norms.
Intention
The likelihood of doing something, like buying a brand or losing
weight. It is a type of judgment about how an individual will behave
toward a particular object or their intention to engage in a
particular behaviour.
THEORY OF PLANNED BEHAVIOUR
THEORY OF PLANNED BEHAVIOUR
 A person’s intention to carry out a
particular behaviour is only possible if
they believe they have some
behavioural control over that
behaviour.
 This will be determined by their past
experiences or perceived obstacles.
 If the individual has favourable
attitudes and subjective norms toward
a particular behaviour, the likelihood
of them actually performing
behaviour in question increases with
their perceived behavioural control.
10. Reasons for her addiction include (150 words):
Social modeling (parents and friends), need for peer
acceptance, rebelliousness, nicotine addiction etc.
11. Theory of reasoned action (125 words):
Attitude: A positive or negative feeling associated with performing a
specific behaviour, e.g. Sally may believe that smoking will make her
popular or may help to lose weight. Subjective Norm: What she believes
others significant others think about her acting in this way and her
motivation to comply. Intention: The likelihood of her doing something.
12. Two examples of public health interventions (100 words):
e.g. Shock tactics showing cigarettes dripping fat to demonstrate the
effect of smoking on arteries (Tobacco Education Campaign, 2004)
13. Effectiveness (250 words):
e.g. Interventions such as the TEC have quadrupled the effectiveness of the
government's anti-smoking campaign, according to the tracking study. The
study found advertising campaigns prompted 32% of recent attempts to
stop smoking compared to GP’s 21%.