Chapter 9 (Davey) - substance use disorders

Drug

a substance that has a physiological effect when ingested or otherwise introduced into the body

Synthetic cathinones/legal highs/bath salts

an emerging group of drugs containing synthetic chemicals related to cathinone, which is an amphetamine-like stimulant found in the khat plant

Pathology associated with substance and drug use falls into two categories

* Substance abuse
* Substance dependency

→ These two categories have been combined into a single substance use disorder in the DSM-5

Substance abuse

A pattern of drug or substance use that occurs despite knowledge of the negative side effects of the drug, but where use has not progressed to full-blown dependency.

Substance dependency

A cluster of cognitive, behavioural, and physiological symptoms indicating that the individual continues use of the substance despite significant substance-related problems

Addiction

when a person’s ‘normal’ body state is the drugged state (so that the body requires the substance to feel normal)

Craving

the strong subjective drive that addicts have to use a particular substance

Psychological dependence

when individuals have changed their life to ensure continued use of a particular drug such that all their activities are centred on the drug and its use.

Tolerance

The need for increased amounts of substance in order to achieve similar effects across time

Withdrawal

where the body requires the drug in order to maintain physical stability, and lack of the drug causes a range of negative and aversive physical consequences (e.g. anxiety, tremors, and in extreme cases death)

Behavioural features of dependence include

*   Unsuccessful attempts to cut down on use of the drug
* A preoccupation with attempts to obtain the drug (e.g., theft of money to buy illegal drugs, driving long distances late at night to buy alcohol, multiple visits to doctors to obtain prescription drugs)
* Unintentional overuse, where people find they have consumed more of the substance than they originally intended (e.g., ending up regularly drunk after only going out for a quick drink after work)
* Abandoning or neglecting important life activities because of the drug (e.g., failing to go to work because of persistent hangovers, neglecting friendships, relationships, childcare, and educational activities)

Gambling disorder

a new inclusion in the DSM-5 chapter on substance-related and addictive disorders; can be considered as a psychological addiction

Prevalence and comorbidity (substance use disorder)

* Global lifetime prevalence: 2%
* Substance use disorders are highly comorbid with other psychological disorders

3 specific groups of substances

* stimulants
* sedatives
* hallucinogenic drugs

Stimulants

substances that increase central nervous system activity and increase blood pressure and heart rate (e.g. cocaine, amphetamines, caffeine)

Sedatives

Central nervous system depressants which slow the activity of the body, reduce its responsiveness, and reduce pain tension and anxiety

* This group of substances includes alcohol, opiates and their derivatives (heroin, morphine, etc.) and synthesized tranquillizers (e.g. barbiturates)

Hallucinogenic drugs

e.g. LSD and other hallucinogenics, cannabis, MDMA (ecstasy)

Binge drinking/heavy episodic drinking

a high intake of alcohol on a single drinking occasion

→ No single definition; in the UK: at least 8 units (males) or 6 units (females) of alcohol in a single day

Ethyl alcohol

the intoxicating constituent of alcoholic drinks

Stages of intoxication

* Stage 1 of intoxication: alcohol acts to relax the individual
* Initially makes the drinker more talkative, friendly, confident, and happy


* Stage 2 of intoxication: As more alcohol is absorbed into the CNS, the drinker becomes less able to make judgements and talk less coherently, memory is affected, and they may switch from being relaxed and happy to emotional and aggressive

Effects of intoxication

* Physical effects of intoxication: motor coordination difficulties (in balance and walking), slowed reaction times, and blurred vision
* The course of alcohol effects is *biphasic* (initial effects act as stimulants, but later effects act as a depressant)

Long-term physical effects of heavy alcohol consumption

* Withdrawal symptoms
* Delirium tremens (DT)
* Hypertension
* Heart failure
* Stomach ulcers
* Cancer
* Cirrhosis of the liver
* Brain damage
* Early dementia
* Many of the effects of long-term alcohol dependence are similar to malnutrition (alcohol has calories but no nutrition)
* Korsakoff’s syndrome

Delirium tremens (DTs)

a severe form of alcohol withdrawal that involves sudden and severe mental or nervous system changes

Korsakoff’s syndrome

a syndrome involving dementia and memory disorders caused by long-term alcohol abuse and dependency (caused by vitamin and mineral deficiencies)

Foetal alcohol syndrome

physiological risk associated with heavy drinking in women, in which heavy drinking by a mother during pregnancy can cause physical and psychological abnormalities in the child

Alcohol use disorder

a problematic pattern of alcohol use leading to clinically significant impairment

Prevalence (use of alcohol)

* The 12-month and lifetime prevalence rates for alcohol use disorder are 13.9%-29.1% (high)
* Dependence is more prevalent among men than women, in younger and unmarried adults, and those in lower socio-economic groups


* Ethnic differences exist
* Polydrug abuse
* Alcohol use disorder is also associated with other mental health diagnoses

Polydrug abuse

abuse of more than one drug at a time

The course of alcohol use disorder

* Alcohol use disorders often pass through stages of heavy and regular drinking, then on to alcohol abuse, and finally ending up in many cases as alcohol use disorder

Risk factors for alcohol use disorders

* A family history of alcoholism (suggesting there may be a genetic component to the disorder, or that the offspring model their drinking behaviour on those of their parents, or that parental drinking gives rise to stressful childhood experiences that precipitate drinking in the offspring
* Long‐term negative affect, including neuroticism and depression
* A diagnosis of childhood conduct disorder
* Experiencing life stress and particularly childhood life stressors
* Holding beliefs that drinking alcohol will have a favourable outcome (e.g., that it reduces tension or makes social interactions easier)

Problems with treating alcohol dependence

* Many people dependent on alcohol use it as a way of coping with life stresses and difficulties, and this can easily lead to relapse when stress is experienced during or after treatment
* Alcohol dependence is often comorbid with other psychological disorders, which make treatment of the dependency more problematic; and
* Alcohol is often part of polydrug abuse, where those dependent on alcohol also abuse other drugs as well, and the use of one drug (e.g., nicotine) is likely to trigger the use of another (e.g., drinking alcohol)

Treatments for alcohol dependence

* Self-help groups (e.g. AA)
* Motivational enhancement therapy (MET)
* Social behaviour and network therapy (SBNT)
* Pharmacotherapy
* Brief interventions

→ the most successful forms of treatment are usually multifaceted approaches that combine a number of individual therapies into a single coherent programme for the client.

Naltrexone

an opioid receptor antagonist which has been found to be beneficial in the control of hyperactivity and self-injurious behaviour (pharmacological treatment alcohol use disorder)

Nicotine physical effects

* It acts as a stimulant by increasing blood-pressure and heart rate
* At the same time, it has a calming effect by reducing self‐reported stress levels and reducing the smoker's feelings of anxiety and anger
* Nicotine has rewarding sensory effects caused by releasing dopamine in the mesolimbic system of the brain (increases firing of midbrain dopamine neurons)

Nicotine negative effects

* Nicotine is an addictive drug that develops physical and psychological dependence
* Smokers report adverse moods when they have not smoked recently, and periods of stress, irritability, and increased pain sensitivity are commonly experienced in the periods between cigarettes or when attempting to quit smoking
* smokers need to smoke simply to experience positive mood levels similar to non-smokers, and that the stress and irritability they experience between cigarettes are withdrawal symptoms caused by their dependence on nicotine  

Prevalence nicotine

* Ca. 1/3 of the adult global population smokes
* Rates in developed nations are gradually falling, while they are rising in developing countries

Tobacco use disorder

a problematic pattern of tobacco use leading to clinically significant impairment or distress

Withdrawal syndrome consists of:

o   Dysphoric or depressed mood

o   Insomnia

o   Irritability

o   Frustration

o   Anger

o   Anxiety

o   Difficulty concentrating

o   Restlessness and impatience

o   Decreased heart rate

o   Increased appetite or weight gain

→ A heavy smoker can exhibit these symptoms after only a few hours of voluntary or enforced abstinence (e.g. plane ride)

Main forms of intervention for smoking

* e-cigarettes
* Nicotine replacement therapy (NRT)
* Bupropion
* Aversion therapy
* CBT
* Complimentary therapies

Rapid smoking

a form of aversion therapy, where the smoker puffs on a cigarette roughly every 4–5 s until they feel ill and cannot take another puff

Hypnotherapy

a form of therapy undertaken while the client is hypnotized

Passive smoking

the breathing in of air that contains other people’s smoke

Second-hand smoking

A person’s exhaled smoke, inhaled by another person

Hashish

the most powerful of the cannabis group of drugs

Marijuana

* a derivative of cannabis consisting of dried and crushed cannabis leaves
* Primarily classified as a sedative/depressant (because of its relaxing effects), however, it can sometimes also have stimulant effects, and make some individuals agitated and paranoid
* Main ingredient is THC
* low addictive properties

Effects of cannabis

* produce feelings of relaxation (at low doses), euphoria, sociability, and sharpened perceptions that sometimes result in mild sensory hallucinations
* But it can also cause difficulties in concentration and impairment of memory

THC effect

* a mild stimulant effect by increasing heart rate and has its psychoactive effects by influencing cannabinoid brain receptors CB1 and CB2 found in the hippocampus, cerebellum, and striatum
* Levels of dopamine are influenced, which plays a role in mediating reward & pleasure, which seems to be the main route through which cannabis has its positive psychoactive effects

Medical application cannabis

* Before becoming illegal, cannabis was primarily used for medicinal purposes

→ Relaxing and analgesic effects

* 1970s: Was used to reduce nausea and lack of appetite caused by chemotherapy in cancer patients
* THC helps block pain signals reaching the brain

Cannabis use disorder

disorder usually develops over a period of time that is characterised by continuing increased use of cannabis and reduction in pleasurable effects

Cannabis intoxication

* symptoms of intoxication after recent use of cannabis begin with a “high” feeling followed by symptoms that include euphoria with inappropriate laughter and grandiosity, sedation, lethargy, impairment in short-term memory, impaired judgment, distorted sensory perception and impaired motor performance
* Occasionally, cannabis intoxication can be associated with severe anxiety, dysphoria, and social withdrawal

Risk factors for developing cannabis dependency

o   Age of onset (the earlier that first use is recorded the higher the likelihood of cannabis dependency)

o   Tobacco smoking and regularity of cannabis use are both independent predictors of cannabis dependency

o   Impulsiveness and unpredictability of moods

o   A diagnosis of conduct disorder and emotional disorders during childhood

o   Dependence on alcohol and other drugs

Motivational syndrome

A syndrome in which those who take up regular cannabis use are more likely to be those who exhibit apathy, loss of ambition and difficulty concentrating

Long-term physical health consequences (cannabis)

o   cannabis generally contains more tar than normal cigarettes and so presents a significant risk for smoking‐related diseases such as cancer (however, little evidence)

o   Regular cannabis use appears to be associated with a reduction in the male hormone testosterone and there is a possibility that this could cause impaired sexual functioning in the young males who are cannabis' main users

o   Chronic cannabis use appears to impair the efficiency of the body's immune system

o   The most probable adverse effects of cannabis on health generally include dependence syndrome, increased risk of psychotic episodes (for those individuals with a prior vulnerability to such episodes), and accidental injury as a result of cognitive deficits that can be experienced within 72 hours of using cannabis

Stimulants

* substances that increase central nervous system activity and increase blood pressure and heart rate
* They facilitate alertness, provide feelings of energy and confidence, and speed up thinking and behaviour

Cocaine

* a natural stimulant derived from the coca plant of South America which, after processing, is an odourless, white powder that can be injected, snorted, or in some forms (e.g. crack cocaine), smoked
* It blocks the reuptake of dopamine in the brain → this facilitates neural activity and results in feelings of pleasure and confidence
* Takes ca. 8 minutes to take effect and lasts ca. 20 min

→ lifetime prevalence: 1-3%

Amphetamines

a group of synthetic drugs used primarily as a central nervous system stimulant

→common forms are amphetamine itself (Benzedrine), dextroamphetamine (Dexedrine), and methamphetamine (Methedrine)

→ lifetime prevalence 1.5%

Caffeine

* a central nervous system stimulant that increases alertness and motor activity and combats fatigue


* found in a number of different products, including coffee, tea, chocolate, and some over-the-counter cold remedies and weight-loss aids

MDMA

(3,4-methylenedioxymethamphetamine), the drug Ecstasy

Ecstasy

an illegal amphetamine-based synthetic drug with euphoric effects

→Also known as MDMA (3,4-methylenedioxymethamphetamine) 

Stimulant use disorder

* Addiction can occur very rapidly, and individuals using amphetamines or cocaine can develop this as rapidly as 1 week
* Sufferers can often develop conditioned responses to drug‐related stimuli (e.g., craving when seeing white powder) which contributes to relapse and treatment difficulties

Cocaine dependence

* occurs when the individual finds it difficult to resist using the drug whenever it is available and leads to neglect of important responsibilities


* criteria for cocaine use disorder are based on those in the general substance use disorder

Withdrawal symptoms of cocaine

Hypersomnia, increased appetite, negative and depressed mood, and these increase the craving for further use or relapse during abstinence

Characteristics of long‐term cocaine dependence

erratic behaviour, social isolation, and sexual dysfunction

→ long-term users may also develop symptoms of other psychological disorders

Physical effects of amphetamines

* Increasing blood pressure and heart rate but can cause headaches, fevers, tremors, and nausea
* Have their effects by causing the release of neurotransmitters norepinephrine and dopamine, and simultaneously blocking their reuptake
* Once high-dose usage is achieved, the stimulant effects also become associated with intense, but temporary, psychological symptoms, including anxiety, paranoia, and psychotic episodes resembling schizophrenia

Methamphetamine

methedrine, a common form of amphetamine

Methamphetamine-dependent individuals (aka ‘speed-freaks’)

* will often use the drug continuously for a number of days, experiencing a continuous ‘high’ without eating or sleeping.
* Followed by a few days of feeling depressed and exhausted, but then the cycle starts again
* Speed freaks often become unpredictable, anxious, paranoid, and aggressive, and may be a danger to themselves and others

Amphetamine intoxication

* amphetamine use, which normally begins with a ‘high’ but is equally likely to be followed by stereotyped, repetitive behaviour, anger, physically aggressive behaviour, and impaired judgment
* Physical symptoms of intoxication include: pupillary dilation, perspiration or chills, nausea or vomiting, chest pains, and in extreme cases, seizures or coma
* Withdrawal symptoms can appear within a few hours or a few days

Benefits of caffeine

increased task focus through alertness, attention, and cognitive function, and also elevated mood and fewer depressive symptoms and lower risk of suicide

Detrimental effects of caffeine

* high doses of caffeine can induce psychotic and manic symptoms, and most commonly, anxiety
* These anxiety‐generating effects of high doses of caffeine make individuals with panic disorder and social anxiety disorder particularly vulnerable to their effects
* 8% of individuals would meet the diagnostic criteria for caffeine use disorder

Caffeine use disorder

* Unsuccessful attempts to cut down use
* Continued caffeine use despite having physical or psychological problems that would be exacerbated by caffeine
* Aversive withdrawal symptoms

Opiates

opium, taken from the sap of the opium poppy

→ its derivatives include morphine, heroin, codeine, and methadone

Methadone

a synthetic form of opium; can be taken orally and is longer lasting

Heroin

* a highly addictive drug derived from morphine, often used illicitly as a narcotic
* Heroin gives a feeling of ecstasy immediately after injection (i.e. ‘rush’, which lasts for 5–15 minutes)
* For about 5–6 hours after this rush, the user forgets all worries and stresses, experiences feelings of euphoria and well‐being, and loses all negative feelings
* individuals who regularly use heroin rapidly develop tolerance effects and experience severe withdrawal symptoms that begin about 6 hours after they have injected the dose

Endorphins

* the body’s natural opioids; the release of these neurotransmitters acts to relieve pain, reduce stress, and create pleasurable sensations
* Opioids have their effects by depressing the central nervous system, and the drug attaches to brain receptor sites that normally receive endorphins and stimulates these receptors to produce more endorphins

Opioids use disorder

the development of tolerance to opiates, in which the user has to use larger and larger doses to experience equivalent physical and psychological effects (also associated with severe withdrawal effects)

→ often associated with a history of drug-related crimes, marital difficulties, and unemployment at all socio-economic levels

Controlled drug user (aka unobtrusive heroin user)

a long-term drug user who has never been in specialized treatment and who displays levels of occupational status and educational achievement similar to the general population

→ While heroin is a dangerous drug, it does appear that some people, in some circumstances, can effectively manage and regulate their use of the drug without problems

Risks that regular opioid users face

* The risk of accidental overdose if inexperienced users fail to properly dilute pure forms of heroin for use
* Being sold street heroin that contains potentially lethal additives (e.g. cyanide or battery acid)
* The risk of contracting human immunodeficiency virus (HIV) or hepatitis from sharing unsterilised needles


* The high cost of opiate drugs also leads regular users into illegal activities to raise money for their dependence (most commonly theft, fraud, and prostitution)

Hallucinogens

Psychoactive drugs which affect the user’s perceptions; they may either sharpen the individual’s sensory abilities or create sensory illusions or hallucinations

→ Unlike stimulants and sedatives, they have less significant effects on arousal levels and are less addictive

Phencyclidines

A group of common hallucinogenic drugs, which include PCP, ‘angel dust’, and less potent compounds (e.g. ketamine, cyclohexamine and dizocilpine)

→ Produce feelings of separation from mind and body in low doses, and stupor and coma at high doses

Lysergic acid diethylamide (LSD)

hallucinogenic drug; it is odourless, colourless, has a slightly bitter taste and is usually taken by mouth

* Physical effects include dilated pupils, raised body temperature, increased heart rate and blood pressure, sweating, sleeplessness, dry mouth, and tremors
* LSD produces sharpened perceptions across a variety of senses

Negative consequences of awareness-enhancing properties of LSD

* If the user is feeling anxious or stressed after having taken LSD, these feelings can be exaggerated to the point where the individual can experience extreme terror or panic (aka. ‘bad trip’)
* Regular users can experience ‘flashbacks’ → vivid re-experiencing of a ‘trip’ that can occur days, months, or even years after the actual LSD trip

Hallucinogen use disorder

* Hallucinogen use is normally restricted to just two to three times per week in regular users, but cravings for the drug have been reported after individuals have stopped using them
* Individuals with hallucinogen use disorder can spend many hours and even days recovering from the effects of the drug, and some hallucinogens are often associated with physical ‘hangover’ symptoms that occur the day after use

Symptoms of ecstasy/MDMA hangovers include

* Insomnia, fatigue, drowsiness, headaches, and sore jaw muscles from teeth clenching.
* Such symptoms will inevitably interfere with normal occupational and social functioning for some time after drug use

→ Ecstasy users appear to be at high risk of substance use disorders (if not with MDMA, then with other substances such as cannabis, opioids, and sedatives)

Dangers associated with regular ecstasy use

* The drug causes severe dehydration by significantly reducing sweat production, which can cause heat stroke in hot environments such as raves or nightclubs—even trying to counteract these effects by increasing fluid intake can cause hyponatremia or water intoxication
* As a stimulant, ecstasy increases heart rate and blood pressure, and this can be potentially dangerous for users with existing cardiovascular problems
* Ecstasy is known to be a selective neurotoxin that destroys the axons to which serotonin would normally

→ Because of this, ecstasy is thought to cause a range of longer‐term problems including memory deficits, verbal‐learning deficits, sleep problems, lack of concentration, and increased depression and anxiety

Aetiology of substance use disorder

* the developmental model of substance abuse and dependency (substance use disorder)
* neurological and behavioural processes

Neurocicuitry of addiction

A broad range of drugs have their pleasurable effects by activating the natural reward pathways in the brain by converging on a common circuitry in the brain's limbic system and many of these drugs also cause permanent adaptive effects on this common pathway that contribute to the progression and maintenance of addiction

Drugs achieve their pleasurable effects by

influencing the dopamine system, and in particular, the dopaminergic neurons in the ventral tegmental area (VTA) of the midbrain and subsequent areas in the limbic forebrain (especially the nucleus accumbens (NAc))

→This VTA‐NAc pathway is arguably the most important reward pathway in the brain and gives rise to the pleasurable effects caused not only by drug use but also by food, sex, and social interactions

Ventral tegmental area (VTA)

Part of the midbrain associated with the dopamine system.

Nucleus Accumbens (NAc)

Part of the limbic forebrain and dopamine system.

3 stages that lead to substance used disorder (aetiology)

* Experimentation
* Regular use
* Abuse and dependence

Risk factors that influence substance use at the experimental stage (stage 1)

* Availability
* Familial factors
* Peer group influence
* Media influence

Social influence model

the nature of an individual's social groups can influence drug use

Social selection model

drug users may eventually choose to join social groups that support and maintain their drug use

Risk factors that influence substance use at the regular use stage (stage 2)

* Mood regulation
* Self-medication
* Long-term expectations & beliefs
* Cultural variables

Reward pathways

the brain neurocircuitry that makes substance use pleasurable

→ One of the main reasons for using drugs is that they have important mood-altering effects

→ Stimulants affect reward pathways in the brain causing the feeling of euphoria, energy, and confidence

Alcohol myopia

the situation where an alcohol-intoxicated individual has less cognitive capacity available to process all ongoing information, and so alcohol acts to narrow attention and means that the drinker processes fewer cues less well

→ lively, friendly environment: will result in the drinker processing only these types of cues, and as a consequence will feel happy and sociable and will not have the capacity to simultaneously process worries or negative emotions

→ non happy drinking situation: the reduced cognitive processing can result in attentional focusing on negative thoughts, experiences, and emotions which means that the drinker experiences more negative affect than if they had abstained

Self-medication

self-administration of often illicit drugs by an individual to alleviate perceived or real problems, usually of a psychological nature

Risk factors that influence substance use at the abuse and dependence stage (stage 3)

(Regular use of a substance is not sufficient to give rise to a substance use disorder)

* Genetic predisposition (e.g. ALDH2)
* Long-term substance-induced cognitive deficits
* Concurrent psychiatric diagnoses
* Poverty

ALDH2

affects the rate at which alcohol is metabolised and will influence the individual's tolerance of alcohol

Treatment of substance use disorders

Treatment interventions with clients suffering substance use disorders are usually multifaceted and address the client's problems at a range of different levels

* Community-based programs
* Behavioural therapy
* CBT
* Family and couples therapy
* Biological treatments