PSY389 Readings week 8

Chapter 7 — Conditioning

1. Classical Conditioning

Classical conditioning = a previously neutral cue becomes able to trigger a response after being repeatedly associated with alcohol.

Example:

Finishing work → drinking alcohol

Over time:

Finishing work → desire to drink

Drinking cues can include:

• places

• people

• times of day

• social situations

• emotions

• bodily sensations.

The more numerous and widespread the cues, the harder drinking behaviour may be to change.

2. Drinking Cues

External cues

Examples:

• pubs

• alcohol bottles

• friends

• parties

• finishing work

• particular meals.

Internal cues

Examples:

• sadness

• loneliness

• anxiety

• anger

• pain

• withdrawal symptoms.

Internal cues can be especially difficult because they are harder to avoid.

Problem drinking may therefore become associated with:

many situations + emotions + bodily states → craving/desire to drink.

3. Withdrawal Can Become a Drinking Cue

A person may discover that drinking relieves unpleasant symptoms such as:

• shakiness

• anxiety

• tension

• nausea

• sweating.

These bodily sensations can then become associated with alcohol.

Example:

falling blood-alcohol level → discomfort → alcohol relieves discomfort

Over time:

discomfort itself → desire to drink.

Thus withdrawal symptoms may become conditioned cues for further drinking.

4. Generalisation

Stimulus generalisation = stimuli similar to an original conditioned cue can also trigger the conditioned response.

Example:

If someone learns:

anxiety/"nerves" → drink

and a hangover produces similar feelings:

hangover symptoms → desire to drink

because the symptoms resemble anxiety.

This helps explain why drinking cues can spread to new situations.

5. Learning & Dependence

The chapter argues that withdrawal symptoms alone do not automatically create craving.

Instead:

withdrawal symptoms + learned association with drinking → craving

Therefore, physiological withdrawal becomes especially important when the person has learned that drinking will relieve it.

This supports the idea that aspects of alcohol dependence are learned, rather than being purely physiological.

6. Extinction

Extinction occurs when a conditioned stimulus is repeatedly experienced without the expected outcome.

Example:

Previously:

Finishing work → alcohol → desire strengthened

Extinction:

Finishing work → no alcohol → conditioned desire gradually weakens

Therefore, repeated exposure to a drinking cue without drinking can reduce the cue's power.

7. Life Changes Can Produce Natural Extinction

Major changes can remove old drinking cues.

Examples:

• moving house

• changing jobs

• entering a relationship

• changing social groups.

If cues disappear, conditioned drinking responses may weaken.

This may partly explain why some people recover without formal treatment.

A problem with hospital/residential treatment is that patients are temporarily removed from their normal drinking cues. They may feel "cured", but urges can return when they go back to their usual environment.

8. Conditioned Tolerance

Tolerance = alcohol has less effect over time, so more is needed to produce the same effect.

The chapter explains this using homeostasis.

Alcohol depresses nervous-system activity.

The body responds with an opposing compensatory response:

Alcohol depresses CNS → body increases activation

With repeated drinking, this compensatory response becomes stronger.

Result:

drug effect − compensatory response = reduced overall effect

→ tolerance develops.

9. Environmental Cues & Tolerance

The body may learn to anticipate alcohol when familiar cues are present.

Example:

pub environment → body expects alcohol → compensatory response begins

If alcohol is then consumed, the compensatory response reduces its effect.

Therefore:

Tolerance can be environment-specific.

If the person drinks in a new environment where familiar cues are absent, their usual tolerance may be reduced.

10. Conditioned Withdrawal

If the body produces its compensatory response because it expects alcohol, but alcohol is not consumed:

compensatory response occurs alone → withdrawal-like symptoms

For alcohol, this may mean increased nervous-system activation.

So:

Alcohol cue → body prepares for alcohol → no alcohol → withdrawal symptoms

This means withdrawal itself can be classically conditioned.

11. Vietnam Heroin Example

The chapter uses research on US soldiers returning from Vietnam.

• Many soldiers became dependent on heroin in Vietnam.

• After returning to the USA, only a small proportion remained addicted.

• Many environmental drug cues from Vietnam were absent at home.

This supports the idea that:

environmental cues contribute strongly to dependence, tolerance and withdrawal.

The chapter applies the same principle to alcohol.

12. Three Conditioning Models of Dependence

1. Compensatory conditioned response model — Siegel

Cues associated with alcohol trigger the body's opponent/compensatory response.

Helps explain:

• tolerance

• withdrawal.

2. Conditioned withdrawal model — Wikler

Cues associated with previous withdrawal begin producing withdrawal-like responses.

These motivate further drug/alcohol use because the person has learned:

alcohol → removes withdrawal symptoms.

3. Conditioned appetitive motivational model

Cues associated with alcohol become linked to its positive/rewarding effects.

Cue → thoughts of alcohol → motivation/craving → alcohol seeking.

The chapter suggests all three processes may contribute to dependence.

13. Instrumental Learning

Instrumental learning = behaviour changes depending on its consequences.

If behaviour produces a rewarding consequence:

→ behaviour becomes more likely

If it produces a punishing consequence:

→ behaviour becomes less likely.

There are four major consequences:

14. Positive Reinforcement

Alcohol may act as a positive reinforcer because its immediate effects can feel pleasant.

Examples:

• relaxation

• enjoyment

• stimulation

• increased sociability

• reduced self-consciousness.

Therefore:

Drink → pleasant feeling → drinking becomes more likely

15. Negative Reinforcement

Negative reinforcement = behaviour increases because it removes something unpleasant.

Example:

Anxiety → drink → anxiety decreases

Therefore drinking becomes more likely next time anxiety occurs.

Another powerful example:

Withdrawal symptoms → drink → withdrawal decreases

This can strongly maintain dependence.

16. Immediacy of Reinforcement

The sooner a reward follows behaviour, the stronger its effect.

This is important in problem drinking because:

Immediate effects

• anxiety relief

• pleasure

• social connection

• reduced withdrawal.

Long-term consequences

• relationship loss

• illness

• job problems

• accidents

• guilt

• legal consequences.

The immediate rewards often overpower the delayed negative consequences.

So:

Immediate reinforcement > delayed punishment

This helps explain why someone may continue drinking despite knowing the long-term harm.

17. Discriminative Stimuli

A discriminative stimulus signals that a particular behaviour is likely to be rewarded.

Example:

Hearing coworkers finish work → signals that a rewarding post-work drink is coming

So the cue does two things:

1. May trigger craving through classical conditioning.

2. Signals that reinforcement is available through instrumental learning.

This shows how classical and instrumental conditioning overlap.

18. Cue-Exposure Treatment

Treatment can use extinction.

Basic idea:

Expose person to alcohol cues + prevent drinking

Repeatedly:

cue → no alcohol

Eventually:

cue → weaker craving

Examples:

• walking past pubs

• entering a pub without drinking

• seeing/smelling alcohol without consuming it.

Exposure is often arranged from:

least tempting → most tempting situation.

19. Evidence for Cue Exposure

Blakey & Baker:

• Identified each person's drinking triggers.

• Ranked them by difficulty.

• Gradually exposed clients to increasingly difficult cues.

• Clients resisted drinking.

Result:

Many previously powerful cues became less likely to provoke desire to drink.

This suggests extinction can reduce conditioned drinking responses.

20. Extinguishing "Loss of Control"

Another study gave dependent drinkers an initial dose of alcohol but then prevented further drinking.

Across repeated sessions:

initial alcohol sensations → progressively less desire for more alcohol

Participants were also asked to:

• hold

• smell

• look at alcohol

without drinking it.

This suggested that apparently automatic "loss of control" may partly involve learned responses that can be extinguished.

21. Social Reinforcement

Alcohol is not reinforced only by its chemical effects.

It can also be reinforced by:

• socialising

• attention

• belonging

• relationships

• cultural expectations.

Problem drinking may become especially difficult to change when someone has few rewarding alternatives.

For example, a person may lose:

• hobbies

• friendships

• employment

• family relationships.

This leaves alcohol as one of the few remaining sources of reinforcement.

22. Social Stability & Recovery

Social stability is described as an important predictor of recovery.

Helpful reinforcers include:

• supportive relationships

• satisfying work

• financial stability

• friendships

• enjoyable activities.

Treatment should therefore ask:

"What rewards will this person gain from drinking less?"

If the answer is "very few", treatment may need to build new sources of reinforcement.

23. Community Reinforcement Programme

Hunt & Azrin developed a programme designed to make:

abstinence rewarding

and

drinking less rewarding.

It included:

• vocational counselling

• job-seeking help

• marital/family counselling

• rebuilding social relationships

• alcohol-free social activities

• practical support.

Family members were encouraged to:

• reduce interaction when the person was drinking

• restore positive interaction when drinking stopped.

Results showed large reductions in drinking compared with controls.

24. Spontaneous Remission

Spontaneous remission = improvement without formal treatment.

Often associated with major life changes such as:

• new relationship

• new job

• moving house

• changed lifestyle.

Instrumental explanation:

new lifestyle → new rewards → drinking becomes less rewarding by comparison

Recovery therefore partly depends on creating alternative sources of reinforcement.

25. Punishment

Punishment = adding an unpleasant consequence that reduces behaviour.

Examples:

• illness

• pain

• criticism

• relationship consequences.

Punishment is more effective when it is:

• immediate

• consistent

• clearly linked to drinking.

26. Response Cost

Response cost = removing something pleasant following behaviour.

Example:

Heavy drinking → partner withdraws attention/support

This may reduce drinking if it is:

• immediate

• consistent

• directed at the drinking behaviour rather than rejecting the person.

The chapter warns that protecting someone from all negative consequences of drinking may unintentionally reduce opportunities for learning and behaviour change.

⭐ Key Things to Remember

• Classical conditioning: alcohol cues become linked with craving.

• More drinking cues → greater difficulty changing drinking.

• Internal cues such as anxiety, sadness and withdrawal can be particularly powerful.

• Generalisation: similar cues can also trigger craving.

• Extinction: repeated cue exposure without alcohol weakens conditioned responses.

• Tolerance and withdrawal can partly become conditioned to environmental cues.

• Positive reinforcement: alcohol provides something pleasant.

• Negative reinforcement: alcohol removes something unpleasant.

• Immediate rewards often overpower delayed negative consequences.

• Discriminative stimuli signal that alcohol reinforcement is available.

• Cue exposure aims to extinguish cue → craving/drinking associations.

• Recovery improves when people develop alternative rewards, such as work, relationships and enjoyable activities.

• Community reinforcement makes sobriety/moderation more rewarding than drinking.

• Overall, the chapter presents problem drinking as partly learned behaviour — and therefore behaviour that can also be unlearned or replaced.

Drummond — Theories of Drug Craving

1. Main Aim

The article reviews major theories explaining drug craving and considers how useful craving is for understanding addiction and relapse.

Three broad groups of theories are discussed:

• Phenomenological models

• Conditioning models

• Cognitive models

Main conclusion:

No single theory fully explains craving, and craving does not necessarily cause relapse.

2. What is Craving?

Craving has been defined in many different ways, including:

• wanting

• urge

• desire

• need

• intention

• compulsion.

Drummond generally defines craving as:

the conscious experience of wanting to take a drug.

Important:

Craving ≠ relapse

Research shows:

• some people relapse without craving

• some people experience craving without relapsing.

Therefore craving is neither necessary nor sufficient for relapse.

3. Historical View of Craving

Older theories treated craving as the central cause of addiction.

For example:

• Jellinek believed craving was closely linked to loss of control and relapse.

• Craving became an important symptom in diagnostic systems.

Later behavioural researchers challenged this.

Main criticism

If someone drinks, researchers may say:

“They drank because they craved.”

But craving is sometimes inferred simply because they drank.

This risks becoming a circular explanation.

Evidence later showed that craving and relapse are only weakly/inconsistently related.

4. Phenomenological Models

These theories are based mainly on:

clinical observation + people's descriptions of craving

They treat craving as a symptom of addiction.

Isbell

Distinguished:

Physical/non-symbolic craving

• associated with physiological withdrawal.

Symbolic craving

• occurs after withdrawal has ended

• may be triggered by environmental cues.

Strength

Focuses directly on the subjective human experience of craving.

Limitation

Mostly descriptive rather than explanatory.

They provide limited guidance about:

• why craving occurs

• how to experimentally test it

• whether craving actually causes relapse.

5. Conditioning Theories

Basic idea:

Drug-related cues become associated with drug effects.

Later:

cue → conditioned response/craving

Examples of cues:

• sight/smell of alcohol

• drug equipment

• particular places

• people

• situations.

6. Conditioned Withdrawal Model — Wikler

Repeatedly:

Drug cues + withdrawal → association

Later:

Drug cue → withdrawal-like conditioned response → craving → drug use

Drug use then removes the unpleasant withdrawal-like state.

Therefore relapse is maintained through:

negative reinforcement

because taking the drug removes an unpleasant state.

Two types of craving

Cue-elicited craving

• caused by drug-associated cues.

Withdrawal-related craving

• occurs during actual physiological withdrawal.

Drummond suggests cue-elicited craving may predict relapse better, because cues often occur in situations where the drug is actually available.

Limitation

The model assumes craving is unpleasant.

But craving can sometimes be experienced as pleasant or exciting.

7. Conditioned Opponent Process Model — Siegel

Repeated drug use causes the body to develop a homeostatic opponent response that counteracts the drug.

Example:

Drug → pleasure

Body responds with:

opponent process → negative state

Over time, the opponent response becomes stronger.

This can explain:

• tolerance

• withdrawal

Drug-associated cues can eventually trigger this negative opponent response before the drug is taken.

So:

cue → negative state/craving → drug use to remove it

Again, drug taking is maintained by negative reinforcement.

8. Conditioned Drug-Like Model

Stewart, de Wit & Eikelboom proposed almost the opposite explanation.

Drug cues become associated with the pleasant effects of drugs.

Therefore:

Drug cue → pleasurable/drug-like response → craving → further drug use

Here craving is:

positively hedonic

and drug taking is encouraged through positive reinforcement.

9. Two-Process Theory

A problem with simple conditioning theories is that they often assume cues cause either:

• withdrawal-like responses or

• drug-like responses.

But evidence does not clearly support only one type.

Two-process theories argue that the effects of cues depend on:

• conditioning history

• emotional state

• interaction between classical and instrumental learning.

Therefore:

Cue → craving does NOT automatically mean → drug use

A cue could sometimes even reduce later drug taking.

This means simple cue → craving → relapse models are probably too simplistic.

10. Incentive-Sensitization Theory

Robinson & Berridge distinguish:

“Liking”

Pleasurable effects of the drug.

“Wanting”

Motivational drive to obtain the drug.

Repeated drug use may sensitise the mesolimbic dopamine system, increasing drug wanting.

Important:

Wanting ≠ liking

A person may strongly want a drug even if they no longer particularly enjoy it.

Wanting can also operate without conscious awareness.

Therefore:

relapse may occur without conscious craving.

Limitation

Much supporting evidence came from animal studies and stimulant drugs, so application to alcohol was uncertain.

11. Cue–Reactivity Model

One of the article's most important models.

Drug cues can produce several kinds of responses:

Autonomic

• heart rate

• skin conductance

• salivation.

Cognitive-symbolic

• subjective craving

• expectations.

Behavioural

• drug seeking.

Important:

Subjective craving is NOT required for drug seeking or relapse.

Cue-reactivity therefore allows researchers to study multiple responses without assuming that craving directly causes relapse.

12. Cue Exposure Treatment

Based partly on cue-reactivity and conditioning.

Person is repeatedly exposed to drug cues without taking the drug.

Possible mechanisms:

Conditioning explanation

Repeated:

cue → no drug

→ conditioned response gradually extinguishes.

Cognitive explanation

Exposure allows people to:

• practise coping skills

• increase self-efficacy

• learn that they can tolerate cues without using drugs.

Therefore cue exposure can test both conditioning and cognitive explanations.

13. Cognitive Social Learning Theory — Marlatt & Gordon

Relapse occurs in high-risk situations.

Whether someone relapses depends heavily on:

Self-efficacy

“Can I resist using?”

Higher self-efficacy → lower relapse risk.

Outcome expectancies

Beliefs about what will happen if they use the drug.

Example:

Positive expectancy

• “Alcohol will relax me.”

Negative expectancy

• “I'll have a hangover.”

Relapse is particularly likely when:

positive drug expectancies + low self-efficacy

are present.

14. Craving in Cognitive Social Learning Theory

Craving may reflect the person's expectation of the drug's positive effects.

It can also reduce self-efficacy:

High craving → “I won't be able to resist” → lower self-efficacy → ↑ relapse risk

Beck et al. described four types of craving:

1. Withdrawal craving → wanting to feel normal again.

2. Lack-of-pleasure craving → using drugs to improve mood.

3. Conditioned craving → triggered by drug cues.

4. Hedonic craving → desire to enhance pleasure.

15. Cognitive Labelling Model

Craving may result from how a person interprets physiological arousal.

Example:

Physical withdrawal sensations → interpreted as “I need a cigarette” → craving

Therefore:

physiological state + cognitive interpretation = craving experience

Potential treatment:

Cognitive reframing

→ teach people to interpret bodily sensations differently.

Limitation

Evidence for this model was limited.

16. Dual Affect Model

Craving may arise from two systems:

Positive-affect urges

Triggered by appetitive/pleasant drug cues.

Negative-affect urges

Triggered by withdrawal or unpleasant emotions.

This explains why both:

positive mood + negative mood

can sometimes be associated with craving.

Limitation

The theory proposed the two systems inhibit each other, but research often finds positive and negative urges are positively correlated instead.

17. Dynamic Regulatory Model

Niaura et al. combine several factors.

Craving results from:

drug cues + positive/negative emotion

Relapse is then influenced by:

• coping

• self-efficacy.

Craving may weaken coping/self-efficacy and therefore increase relapse risk.

However, research found that once:

• self-efficacy

• coping

• anxiety

were controlled, craving was no longer a significant independent predictor of relapse.

Therefore:

Self-efficacy may mediate the craving → relapse relationship.

18. Cognitive Processing Model — Tiffany

A very important theory.

Tiffany argues that repeated drug use becomes automatic, similar to driving a familiar route.

Normally:

Cue → automatic drug-use sequence → drug use

No conscious craving is necessarily required.

When does craving appear?

When the automatic drug-use sequence is blocked.

Example:

Person wants alcohol → pub is closed.

Now non-automatic, effortful processes occur:

• frustration

• thoughts about alcohol

• problem solving

• conscious desire/craving

• trying to find another source.

Therefore:

Craving may arise when drug-taking is prevented, rather than being what normally causes drug taking.

This helps explain why relapse can occur without conscious craving.

19. Craving & Relapse

A central conclusion is:

❌ Too simplistic:

Craving → relapse

More realistic:

Relapse depends on interacting factors such as:

cues + automatic behaviour + mood + expectancies + coping + self-efficacy + drug availability + craving

Research generally does not support a simple direct causal relationship between craving and relapse.

20. Problems Measuring Craving

Craving may change rapidly over:

• minutes

• hours

• days.

Therefore asking:

“How much craving have you had this week?”

may poorly predict a relapse occurring at one particular moment.

The article argues that research needs to examine the temporal dynamics of craving.

Short-lived cue-elicited craving may be more relevant than general/background craving.

Measurement should potentially include:

• subjective reports

• physiological responses

• behaviour.

21. Treatment Implications

Cue exposure

May reduce responses to drug cues through:

• extinction

• increased coping/self-efficacy.

Cognitive therapy

May target:

• dysfunctional beliefs

• outcome expectancies

• interpretation of urges

• coping

• self-efficacy.

Medications

Examples discussed:

• naltrexone

• acamprosate

These are sometimes called “anti-craving” medications.

However, Drummond warns that:

reducing craving does not necessarily mean reducing relapse.

Their benefits may operate through mechanisms other than craving.

⭐ Key Conclusions

• Craving = conscious desire to take a drug, but definitions vary.

• Craving was historically considered the central cause of addiction.

• Evidence shows craving is neither necessary nor sufficient for relapse.

• Phenomenological theories describe the experience of craving but explain it poorly.

• Conditioning theories explain how drug cues acquire motivational significance.

• Conditioned responses can be either withdrawal-like or drug-like.

• Incentive sensitisation: “wanting” and “liking” are different; wanting may occur unconsciously.

• Cue-reactivity includes physiological, cognitive and behavioural responses and does not require subjective craving.

• Cognitive social learning theory: relapse depends strongly on self-efficacy and outcome expectancies.

• Tiffany: drug use may become automatic; craving often occurs when automatic drug-taking is blocked.

• Overall, simple craving → relapse models are not well supported.

• The best theories integrate conditioning, cognition, emotion and behaviour rather than treating craving as the single cause of addiction.

Siegel — Pavlovian Conditioning & Drug Overdose

1. Main Idea

The article argues that drug tolerance is partly learned through Pavlovian conditioning.

Drug-associated cues can trigger compensatory bodily responses that reduce the drug’s effect.

So, if a person takes their usual dose in an unfamiliar setting, those conditioned compensatory responses may be weaker or absent.

Result:

usual dose + reduced tolerance → greater overdose risk

This may explain some overdoses that occur even when the dose is not unusually large.

2. What is Drug Tolerance?

Tolerance = the same dose of a drug produces a smaller effect after repeated use.

For heroin:

• experienced users can tolerate doses that would be lethal to inexperienced users.

However, many overdose victims are long-term users, not novices.

Post-mortem studies have also found that some overdose victims did not have unusually high morphine levels, suggesting that overdose can sometimes involve a failure of expected tolerance rather than simply taking too much.

3. Tolerance as a Learned Process

The article argues that tolerance is not purely pharmacological.

Evidence includes:

• tolerance can persist after long drug-free periods

• it can depend on environmental cues

• it behaves in ways similar to learned responses.

Therefore:

Tolerance = physiological adaptation + learning

4. Pavlovian Conditioning Model

In Pavlovian conditioning:

• UCS = drug

• UCR = body’s direct compensatory response to the drug

• CS = cues associated with taking the drug

• CR = learned compensatory response triggered by those cues

So over time:

Drug cues → body prepares for drug → compensatory response

This response reduces the drug’s effect and contributes to tolerance.

5. Conditioned Compensatory Response

The conditioned response is often opposite to the drug’s effect.

Example:

If a drug increases heart rate:

body learns to decrease heart rate in anticipation

These compensatory responses help maintain homeostasis.

Therefore, familiar drug cues can make a person appear more tolerant because the body is already preparing to oppose the drug.

6. Situational Specificity of Tolerance

A key concept:

Situational-specificity of tolerance

Tolerance is stronger in the environment where the drug is usually taken.

Why?

Because familiar cues trigger the learned compensatory response.

So:

usual setting → strong compensatory response → greater tolerance

unusual setting → weak/no compensatory response → less tolerance

This has been shown for many drugs, including:

• opiates

• alcohol

• nicotine

• barbiturates

• benzodiazepines.

7. Why Can an Unfamiliar Setting Increase Overdose Risk?

If someone usually uses a drug in one context:

familiar environment → conditioned compensation

But then takes the same dose somewhere new:

new environment → weaker compensatory response

Therefore the drug has a stronger-than-expected effect.

This can make a previously tolerated dose dangerous.

8. Animal Evidence

A classic heroin study tested 107 rats.

Three groups:

• Same-Tested: previously received heroin and got the high dose in the same environment

• Different-Tested: previously received heroin but got the high dose in a different environment

• Control: received heroin for the first time.

Mortality:

• Control = 96%

• Different-Tested = 64%

• Same-Tested = 32%

So rats given the high dose in the usual environment were much more likely to survive.

This strongly supports the idea that environmental cues contribute to tolerance.

9. Evidence Across Other Drugs

Similar effects were found with:

• pentobarbital

• ethanol.

Changing the drug-taking context increased lethality.

This suggests the effect is not unique to heroin.

10. Human Evidence — Heroin Users

Clinical studies also support the theory.

In one study:

• heroin users who had not overdosed had all injected in a usual environment

• 52% of overdose cases had injected in an unusual environment.

This suggests overdose is more likely when the drug is taken in a context not previously associated with drug use.

11. Medically Prescribed Opioids

The same principle may apply in medical settings.

A case described a patient with pancreatic cancer who regularly received morphine in his bedroom.

One day:

same usual dose + different room

→ overdose symptoms occurred

→ the patient later died.

The explanation offered is that the unfamiliar environment did not trigger the usual conditioned compensatory response.

12. Route of Administration Can Also Be a Cue

Drug-associated cues are not only external surroundings.

They can also include interoceptive cues, such as:

• route of administration

• sensations immediately after taking the drug.

So changing:

oral → transdermal

or

intraperitoneal → intravenous

may reduce learned tolerance.

The body may have learned to associate a particular administration procedure with the drug effect.

13. “Overdose” May Sometimes Be a Misleading Term

The article argues that some heroin deaths may not be caused by an unusually large dose.

Instead:

the person may fail to display their normal tolerance

because the usual conditioned cues are absent.

Therefore:

same dose ≠ same effect in every context

14. Other Causes of Overdose Still Matter

Siegel does not claim conditioning explains every overdose.

Other factors include:

• genuinely excessive doses

• combining opioids with other drugs

• contaminants/adulterants

• pharmacological interactions.

Conditioning is presented as one important contributing mechanism.

15. Main Conclusion

The central argument is:

Drug-associated cues become part of tolerance.

Therefore:

familiar cues present → stronger tolerance

familiar cues absent → tolerance may fail

This can increase overdose risk even in experienced users.

The article concludes that using heroin in an unusual or unfamiliar setting should be considered dangerous.

⭐ Key Things to Remember

• Tolerance is partly learned, not purely biological.

• Drug cues can trigger conditioned compensatory responses.

• These responses oppose the drug’s effects and contribute to tolerance.

• Tolerance is situation-specific.

• Familiar setting → more tolerance

• Unfamiliar setting → less tolerance

• A usual dose may become more dangerous in a new context.

• Animal studies strongly support this effect.

• Human overdose studies are consistent with the same pattern.

• Cues can be external and internal/procedural.

• Conditioning may explain some overdoses, but not all.

• Best summary: overdose risk can increase when conditioned tolerance fails.