Conditioning Models of Addiction, Part 2

In our last Briefing, we described classical conditioning as a process that involves a neutral unconditioned stimulus (UCS), such as a coloured light, becoming rewarding and influencing behaviour because it has reliably preceded a reward such as food.

During a history of drug use, certain stimuli, such as environmental contexts or drug paraphernalia, reliably accompany drug administration. These stimuli, by virtue of their pairing with the drug effects, become conditioned stimuli (CS) capable of eliciting conditioned responses (CRs), e.g. drug-seeking behaviour.

There are three ways that classical conditioning may be involved in problematic substance use or addiction.

In the first proposed model of conditioning, the conditioned withdrawal model, Wikler (1948) proposed that environmental stimuli paired with drug withdrawal became conditioned stimuli (CS) capable of eliciting conditioned withdrawal reactions (CRs).

For example, in people dependent on heroin, withdrawal symptoms can occur and be paired repeatedly with environmental stimuli. At a later time, when the individual is no longer dependent, the environmental cues alone can be enough to elicit the symptoms of withdrawal.

The cues that trigger conditioned withdrawal can be both external (places or situations) or internal (moods). Conditioned withdrawal can play a prominent role in relapse.

In fact, the conditioned withdrawal model of addiction involves both classical and operant (or instrumental) conditioning. Repeated pairing of environmental stimuli with withdrawal results in these stimuli being capable of inducing conditioned withdrawal (classical conditioning).

The instrumental conditioning component involves the person taking the drug to alleviate an aversive state, the withdrawal symptoms, which can be regarded as a negative reinforcer.

The second classical conditioning involves the concepts of conditioned drug-opposite responses and conditioned tolerance.

Whenever a disturbance occurs in the body, such as produced by a drug, a physiological process known as homeostasis, in which the body tries to counteract the disturbance, comes into play.

For example, amphetamine enhances release of the neurotransmitter dopamine in the brain, but at the same time regulatory mechanisms reduce dopaminergic function in order to try and maintain the status quo – although the amphetamine still increases dopamine function overall.

Researchers believe that these compensatory mechanisms can eventually be triggered by stimuli and cues previously associated with drug administration, and this can happen even before the drug is taken.

In situations where the predictive stimuli appear but no drug is taken, the body’s compensatory mechanisms come into play and go unopposed because there is no drug effect. This can be expressed as overt physiological reactions and/or form the basis for the subjective experience of withdrawal sickness and craving.

Take for example a person who is drinking alcohol every evening to reduce the anxiety they have experienced from working in a stressful job. The clock at work approaching 17.00, and the sights and sounds of the pub, act as conditioned stimuli to the anxiety-alleviating effects of alcohol.

If the person were to attend a school play one evening, without going to the pub, their body’s compensatory mechanisms would come into play but not be diminished by the physiological effects of alcohol. The person would experience the opposite subjective effects to those produced by alcohol, i.e. anxiety.

According to this model, tolerance and withdrawal symptoms are intimately linked.

Tolerance – the gradual diminution of effect following repeated administration of the same dose of drug – is thought to occur because of the homeostatic processes that occur in the body to counteract the action of a drug. The homeostatic (or opponent) responses are thought to be strengthened by repeated drug administration, and the net effect of the drug (original effect minus the opposing effect) is therefore reduced.

These processes are explained in more detail by the Opponent Process Theory of Solomon and Corbit (1973), summarised in Robert West’s book “Theory of Addiction”.

Shepard Siegel (1975) first proposed that a complete account of tolerance requires an appreciation of the role of environmental influences or cues.

There is now an abundant evidence showing that animals pre-administered a drug repeatedly in one environment and tested behaviourally in another environment, will not show as much tolerance as those animals given chronic drug and behavioural testing in the same environment.

An important consequence of this idea in relation to heroin overdose was illustrated by Shepard Siegel in the early 1980s. Tolerance develops to the effects of heroin, so that users face the possibility of overdose (and death) if they take much larger amounts of drug than normal.

Siegel reasoned that if tolerance to heroin was partially conditioned to the environment where the drug was usually administered, if the drug was administered in a new setting, much of the conditioned tolerance would disappear, and the person would be more likely to overdose.

In his study, many heroin users admitted to hospital suffering from a heroin overdose reported that they had taken this near-fatal overdose in an unusual environment, or that their normal pattern of use was different on that day.

Recommended reading:

Robert West (2006) Theory of Addiction. Blackwell Publishing.

Nick Heather and Ian Robertson (2001) Problem Drinking. Oxford Medical Publications.

< pdf document

> Conditioning Models of Addiction, Part 3

The Drug Experience: Heroin, Part 2

Heroin can have a devastating effect on human lives, although as we described in the last Briefing, evidence indicates that it has this impact on only a minority of people who first try the drug.

In this Briefing, we start to describe the experiences of people whose lives are seriously affected by heroin. The experiences are based on those described in the seminal book Beating the Dragon: The Recovery from Dependent Drug Use by James McIntosh and Neil McKeganey, and our own research with clients on the Peterborough Nene Drug Interventions Programme.

The majority of people in these studies committed crimes to fund their heroin habits. In fact, the Peterborough project recruited many of the highest-level offenders in Peterborough. However, it must be emphasised that this does not mean that all people who take heroin commit crimes.

Many people who use heroin describe a steady progression from use of legal substances (alcohol, solvents), through to softer drugs such as cannabis and then on to heroin.

The most frequently cited reasons for trying heroin are curiosity and a desire to comply with the expectations of others, particularly of a peer group. However, there is little indication that heroin users are pressurised to take the drug for the first time—the vast majority feel that they have made their own decision.

However, this decision is often not well-informed. Many of our interviewees emphasised that they were naïve about the effects of heroin before they first tried the drug. Some believed that it was no worse than other drugs; others were not even aware that they were trying heroin.

Some people admit to not thinking about the consequences of their actions, and in fact do not think much about their drug use at all. Many others, when they first start taking heroin, are confident that they will not become addicted. A common belief is that:

‘… addiction is not something that could happen to me; it happens to other people.’

Many of our interviewees discussed the ease of availability and frequent exposure to various substances, including heroin. Drugs were rife on the housing estates in Peterborough on which some of our interviewees had been brought up.

Many people who first try heroin will say that they experienced a feeling of great relaxation and detachment from the outside world. They may feel drowsy, experience a clouding of mental functioning, and feelings of warmth (from dilation of blood vessels). They may also experience feelings of euphoria, particularly after intravenous injection. Heroin also reduces anxiety and emotional pain—it helps people escape from reality.

There is a reduction in respiration, heat rate and pupil size. Many first-time users feel sick and vomit, although this vomiting is often not enough to stop them using again, as the pleasurable effects far outweigh this negative side effect. This vomiting subsides in many people after the first few experiences of heroin.

Many first-time users try the drug again because they enjoyed the first experience. Others, some of whom may even have had a bad initial experience, continue taking the drug because they remain in the same social circles that led them to their first use.

Some people very rapidly move towards daily use of the drug, whilst others may continue to use on a periodic basis over a period of weeks or months. Our Peterborough sample, whose lives were badly affected by heroin, all ended up using the drug daily.

Heroin users develop a tolerance to the drug, such that increasing amounts of the drug must be taken in order to achieve the same positive effects. This tolerance results in the drug habit becoming more costly.  Some users will shift from smoking heroin to injecting the drug because the same effects can be achieved with much smaller amounts of the drug.

They may also start injecting drug as part of a continued desire to experiment and to find new “highs”. As part of this process of finding new “highs”, some people use multiple drugs, sometimes at the same time. Use of benzodiazepines, legally and illegally obtained, is common amongst heroin users.

Many heroin users recognise the decision to inject as having been a significant step in their drug using career. Injecting is an invasive process that heightens the risk of overdose and introduces additional risks such as contracting hepatitis C, HIV and other blood-borne infections.

Often, these are not the factors that make people reluctant to start injecting. Rather, they appear to be apprehensive about the actual process of injecting. Many users have a fear of injections and, of course, generally people do not know how to inject. Other users help first-time injectors and continue to do so until the latter person feels confident in the process.

There are variations in individuals’ experiences when they first inject heroin. Many people experience a pronounced euphoria almost immediately after injection. Other people do not experience this rush, whilst others report feeling very ill.

However, many of those who initially have negative experiences continue to persevere taking the drug and eventually became intravenous drug users.

In our next Briefing, we will continue to look at the experiences of those people whose lives are seriously affected by heroin, focusing first on the withdrawal syndrome.

Recommended Reading:

Beating the Dragon: The Recovery from Dependent Drug Use by James McIntosh and Neil McKeganey, Prentice Hall, 2002.

The Heroin Users by Tam Stewart, Oram Press, 1996.

Using Heroin, Trying to Stop and Accessing Treatment by Aimee Hopkins and David Clark, 2005.

> pdf document

> Part 3

Alcohol Dependence

Here is an article I first wrote as a Background Briefing for Drink and Drugs News (DDN), the leading UK magazine focused on drug and alcohol treatment, in February 2005.

‘There has been a considerable scientific effort over the past four decades in to identifying and understanding the core features of alcohol and drug dependence. This work really began in 1976 when the British psychiatrist Griffith Edwards and his American colleague Milton M. Gross collaborated to produce a formulation of what had previously been understood as ‘alcoholism’ – the alcohol dependence syndrome.

The alcohol dependence syndrome was seen as a cluster of seven elements that concur. It was argued that not all elements may be present in every case, but the picture is sufficiently regular and coherent to permit clinical recognition.

Read More ➔

The Drug Experience: Cocaine, Part 1

Exploring the dynamic world of heavy cocaine use as revealed in a provocative, high-quality study by Dan Waldorf and colleagues. This research, conducted in the US in the 1980s, challenged many of the prevailing myths about cocaine. (875 words)


There is a good deal of misinformation about cocaine, which does little to help society tackle the problems that excess use of this drug can produce.

In their book Cocaine Changes: The Experience of Using and Quitting, Dan Waldorf and his colleagues state that they set out to study cocaine users and present their world as they see it, without making moral judgements about the drug-using behaviours.

The research involved interviewing 267 current and former heavy users of cocaine from Northern California. The sample did not include people in treatment programmes or in prison, as is common in other research. Most of the respondents were ‘solidly working- or middle-class, fairly well-educated, and steadily employed.’

Nearly all the respondents first tried cocaine when it was offered by a trusted friend. Many of the sample reported that they did not get high the first time they snorted cocaine. They had to learn both to experience and then to appreciate the subtle euphoric effects of the drug.

The majority of respondents increased their use gradually—there was no uniform progression or pattern. The slow escalation was likely due in part to the general greater availability of the drug. Two other factors were often cited as contributing to escalating use: a slow increase in tolerance for the drug, and the seductive and insidious nature of the drug itself.

The tolerance reported with cocaine appeared to be somewhat different to that observed with opiates. Whilst some users reported increasing their doses of drug, they did not generally report decreased effects of the same dose. Rather than needing more of the drug to get the same effect, they reported wanting the same effect again and again.

Many participants ‘… agreed that cocaine’s euphoric effects offered not only a sense of well-being, but a feeling of mastery or power that was so reinforcing it often led them to use more frequently than they planned or expected.’

The researchers described four relatively discrete patterns of use. Hogs showed a consistent, very heavy daily use. This pattern of use caused more dramatic effects, greater compulsion, as well as marked painful ‘comedowns’ and depression.

Nippers used regularly, often every day, but only in relatively small amounts. These users kept their drug use subordinated to work and family responsibilities, and often avoided the negative effects associated with heavy use.

Bingers used cocaine heavily and then lay off the drug for days or weeks. Use was often constrained by personal finances or by prolonged negative effects. Some bingers found their binges getting longer and longer. Ceremonial or occasional users used the drug on special social occasions.

The researchers reported a considerable movement by individuals from one form of use to another. Although some users followed a downward spiral from experimental use to addiction, as many others nipped and then binged and then nipped again. Others moved from heavy binge use or sustained abuse to ceremonial use.

One striking aspect of the study was the proportion of people who used the drug on a controlled basis—approximately 50%.

Long-term daily use of cocaine or regular heavy binges often led to problems. The most frequently mentioned were nasal irritations, insomnia, paranoia, strained relationships with wife or husband, depleted savings, hangover days at work, and periodic sexual difficulties. The most frequent and severe problems were reported by the heaviest users.

Some of these problems were reported as serious, but many were not. Most of the respondents appeared to find most of the problems manageable most of the time. They seemed to get pleasure from cocaine, and accepted the problems as part of the territory.

Most of the sample agreed that moderate use of cocaine can be an exceedingly enjoyable experience —it produced euphoria, more energy, a certain intellectual focus, enhanced sensations, an increased sociability and social intimacy.

However, daily use or regular binges transformed the experience of the cocaine high. The initial euphoria slowly and subtly became dysphoria, feelings of well-being turned into feelings of being unwell and unhappy. Feeling energetic was replaced with feeling apathetic.

These changes in physical feelings were accompanied by transformations in social experience. The person used the drug in isolation, rather than in social groups as was done initially.

Some heavy users noted psychological transformations. The world that had once been good to live in became a place that was far less hospitable—paranoia increased and depression sometimes developed.

A shift in the balance between positive and negative effects of cocaine occurred. The shift to the negative often resulted in considerable psychological pain, and a questioning of the rationality and desirability of continuing to use the drug.

At this time, those people with conventional stakes in families, homes, jobs, communities and identities tended to find the resources and resolve to abstain or reduce their drug use.

Those with fewer such stakes and social supports were more likely to feel indecisive and helpless to overcome their cocaine use problem.

Recommended reading:

Cocaine Changes: The Experience of Using and Quitting by Dan Waldorf, Craig Reinarman and Sheigla Murphy. Temple University Press, USA.

> pdf document

> Part 2

 

 

The Drug Experience and Beyond: Amphetamine

The experience of taking amphetamine, including the subjective pleasurable experiences of initial use, amphetamine-induced anxiety and psychosis, and withdrawal symptoms following long-term use. Also includes a brief consideration of the various factors that can influence the amphetamine experience. (964 words)


The ‘drug experience’ produced by a particular psychoactive substance depends on both drug and non-drug factors. Drug factors are the chemical properties or type of drug used, the dose, route of administration, and presence or absence of another drug. Non-drug factors include personal characteristics of the user (e.g. biological make-up, personality, previous experience), and the context or setting in which the drug is taken.

A person will first try a drug because of social or intrapersonal factors, such as curiosity about the effects of a drug, or the fact that their friends are taking it. They will probably have certain expectancies about the effects of the drug from conversations with experienced users and/or because of media exposure.

Once a person has taken a drug, the drug experience creates cognitive expectancies which become another factor that influences subsequent drug-taking. A person may continue to take the drug to increase his psychological comfort or change his level of consciousness.

Low doses of amphetamine produce a number of subjective effects: feelings of euphoria; heightened alertness; increased energy and excitement; increased feelings of well-being, confidence and power; increased ability to concentrate and stay awake; increased sociability and friendliness; a feeling of being less bored or tired; hyperactivity, talkativeness, and a rapid flow of ideas; a suppression of sexual inhibitions; lack of desire for food; nervousness and anxiety.

With higher drug doses, there are other effects. These are much more likely to occur when the drug has been taken repeatedly rather than on a single occasion. The user may experience repetitive (stereotyped) thought patterns and show repetitive behaviours, e.g. continually take apart and re-assemble some object, or pick continually at their skin. They may show restlessness, irritability, and various types of anxiety condition, including panic states.

The person may develop suspiciousness, paranoia (delusions of persecution), and experience visual and auditory hallucinations. This is known as amphetamine psychosis, which resembles paranoid schizophrenia.

Amphetamine psychosis is usually seen with chronic use of drug, but can be seen after an acute administration. The incidence of amphetamine psychosis increases greatly when the user switches to intravenous drug administration.The psychosis is transitory and usually terminates after drug use is terminated. Long-term amphetamine use can sometimes lead to sudden and intense acts of aggression and violence.

The subjective effects of amphetamine and similar-acting substances are not fixed. The amphetamine-like stimulant methylphenidate (Ritalin) is, paradoxically, used to treat hyperactivity in children. Some adults report the drug exerting a calming effect, allowing them to cope better.

In well-controlled laboratory conditions, under conditions where neither subject nor experimenter knew whether drug or placebo was administered, a fixed dose of amphetamine produced either euphoria or anxiety in different subjects.

Once a person has tried amphetamine, they may use the drug on a recreational basis, even over an extended period of time. They may keep a strict adherence to a particular pattern of drug use so that the drug is only used on certain occasions (e.g. weekends). The user retains control over drug use and there may be no medical or social complications—however, there is the possibility of legal sanction. Of course, a person may try amphetamine once and never do so again.

However, the pattern of drug-taking may intensify and a number of changes may occur. For example, a person may switch from oral or intranasal use to intravenous use. Drug effects will intensify when such a change occurs.

In another pattern of use, the person initiates repeated ‘runs’, taking amphetamine for hours and sometimes days. They may snort new lines of drug whenever they feel the drug effects wearing off. This pattern of drug-taking is more evident with cocaine, which is a much shorter–acting drug.

In yet another pattern of use, they may chronically abuse amphetamine in combination with depressant drugs. They may drink large amounts of alcohol whilst under the influence of amphetamine.

Users may use depressant drugs (benzodiazepines, alcohol, opiates) to take ‘the edge off’ the stimulant, and help them feel less anxious. Research suggests that users who abuse stimulants and depressants experience more psychological and physical problems than those who only abuse stimulants.

Tolerance develops to many of the psychological and physical effects of amphetamine, e.g. euphoria, anorexia, hyperthermia and hypertension. This tolerance may develop within hours to days. However, there appears to be little tolerance to the anxiogenic effects of the drug. In fact, repeated use of amphetamine may sensitise individuals to amphetamine psychosis.

The effects of a single dose of amphetamine lasts 2 – 4 hours and generally leaves the user feeling tired after the drug’s primary effects are over. It may take as long as a couple of days to feel normal again. With chronic drug use, feelings of tiredness, lethargy and irritability become stronger and may have a more dramatic onset following the wearing off of drug effects.

The user may want to keep taking drug to avoid these feelings. Tolerance develops with regular use and higher doses will be required. Eventually, ‘what goes up must come down’. The ‘withdrawal’ effects are even stronger when a user has completed repeated ‘runs’ over a period of days. Amphetamine produces a withdrawal syndrome, which not only includes tiredness, but also anhedonia (an inability to feel pleasure), depression, anxiety, dysphoria, sleep disturbances, and a strong craving for drug.

The person may experience terrible mood swings as he oscillates between periods of drug-taking and withdrawal. He may experience periods of paranoia and anxiety when taking the drug, and periods of deep depression when not taking the drug. The impact of this on psychological well-being can be considerable.

> pdf document

Alcohol Dependence

Looks at the cluster of seven elements that make up the template for which the degree of alcohol dependence is judged. (900 words)

Read More ➔

Stigma and Recoveryism

UnknownBill White has been pushing out the blogs recently and I have missed some. I want to try and help to increase his readership, so it is catch-up time. Here’s the first, from August 28th – it represents some powerful writing. In my humble opinion, Bill at his best!

‘The suggestion that there are multiple and diverse pathways of long-term addiction recovery has evolved from a heretical statement to a central tenet of an international recovery advocacy movement. As tens of thousands of people representing diverse recovery experiences stand in unison in September’s recovery celebration events, it is perhaps time to explore and then put aside past divisions within and between communities of recovery.

In 2006, Tom Horvath, President of SMART Recovery, penned a brief article in which he coined the term recoveryism.  He used the term to depict assertions that a particular approach to addiction recovery was superior to all others – that there really is only ONE effective approach to addiction recovery. 

Read More ➔

The nature of alcohol dependence

P1011087Here’s an article on alcohol dependence you can find in our Articles section:

There has been a considerable scientific effort over the past three decades in to identifying and understanding the core features of alcohol and drug dependence. This work really began in 1976 when the British psychiatrist Griffith Edwards and his American colleague Milton M. Gross collaborated to produce a formulation of what had previously been understood as ‘alcoholism’ – the alcohol dependence syndrome.

Read More ➔