Addiction and substance use disorders Flashcards
What are the key features of addiction or substance abuse?
A compulsion to take a substance
Escalating the amount used
Withdrawl symptoms in cessation
Tolerance develops
Neglect of other activities
Persistent use despite harm
Loss of self control
Return to negative patterns of behaviour after cessation
What is substance misuse?
Using non-therapteutic doses of drugs in a way that is potentially harmful but not yet dependent
What is the difference between hazardous and harmful drinking?
Hazardous is above the limit and has the potential to cause damage
Harmful drinking - clear evidence of alcohol related problems for usage, e,g liver disease
What is the neurobiology dopamine theory of addiction?
Dopamine reinforcement pathway - VTA to nucleus accumbens and the prefrontal cortex
Is an endogenous opiod system
Feels of pleasure and reward
Repeated use and feeling of pleasure reinforces behaviour by operant conditioning
Require more substance to have the same affect as neurotolerance develops.
This is within the mesolimbic system
How does operant conditioning link to repeated drug use in addiction?
Reward - dopamine reward pathway is activated
Punishment - avoid the withdrawl symptoms by using the substance again
What is the link between risk factors, drug use and addiction?
Biology, genes, environment and personal variation are all risk factors for drug use
After the drug has been used brain mechanisms reinforce patterns of addiction.
What are the psychosocial impacts of legal and illegal drug classification?
Legal drugs are more commonly abused as easier to access and less social barriers to their use
More ‘harmful’ class A drugs are less accessible, more discrimination against their users so are rarer patterns of addiction.
How are illegal drugs classified?
From class A, B and C
Class A being percieved by parliament as the most harmful and class C as the least harmful
What is the deal with class A drugs?
Examples and prison sentences
Ecstasy, LSD, heroin, Cocaine, magic mushrooms, injecting amphetamines
Up to 7yrs in prison and an unlimited fine for possesion
For production - life in prison and unlimited fine
What are some examples and the prison sentences for class B drugs?
Ampehtamines
Cannabis
Methylphenidate
Possession - up to five years in prison and/or unlimited fine
Production/supply - 14yrs in prison and/or unlimited fine
What are some examples of and prison sentences for class C drugs?
Tranquilisers, painkiller, gamma hydroxybutyrate
Possesion - 2yrs prison and/or unlimited fine
Supply/production - up to 14yrs in prison and/or an unlimited fine
What are the patterns of alcohol dependence and use?
10% men and 3% of women show signs of dependence
Strong link to lots of cultures and rituals
93% of men and 87% of women drink alcohol
Responsible for over 1 million hospital admission a year in England
What are the mechanisms of action of alcohol?
Increase cell wall fluidity and permeability
Enhancement of GABA-A transmission (reduce anxiety)
Release dopamine in mesolimibc system (feel good)
Inhibit NMDA glutaminergic transmission (Pain killer)
What are the effects of alcohol on the user?
Disinhibition, elevation of mood, increased socialisation
Unstable mood, impaired judgement, aggressiveness, slurred speech and ataxia
How is alcohol normally metabolised?
Ethanol is broken down by alcohol dehydrogenase to acetaldehyde
Acetaldehyde is broken down by aldehyde dehydrogenase to acetyl CoA
How is alcohol metabolised when there is excess/high alcohol consumption?
The microsomal ethanol system
Breaks ethanol down into acetaldehyde by reducing NADPH+
What is the clinical importance and mechanism of disulfiram?
Used to prevent alcohol consumption
Inhibits aldehyde dehydrogenase
Leading to more rapid accumulation fo acetaldehyde if alcohol is drank, this causes nause and unpleasant affects thought to discourage alcohol intake
What are some of the risk factors for alcohol dependence?
Genetics - first degree relative who showed dependence, ALDH variation in asian groups is less effective
Psychological trauma or abuse
Behavioural - modelling and peer influences
Social cultural - deprivation, poor familial support
What is the difference between type 1 and type 2 alcoholics?
Type 1 - late onset, typically caused by interaction between environment and genes, strong psychological dependence, equally common in males and females
Type 2 - early onset, due to genetic vulnerability, often antisocial PD and novelty seeking behaviour, more common in men than women
What are some of the chronic medical complications of alcohol use?
Hepatic disease - fatty liver, hepitis, cirrhosis
Gastro-intestinal problems: such as pancreatitis, metaplasia, impaired absorption and diahorrea
Cancers
Cardiovascular: High BP, cardiomiopathy, atrial fibrilation
Respiratory; desensitises cillia.
Genito-urinary : erectile dysfunction and hypogonadism
What are some of the acute health problems associated with medical use?
Becomes toxic between 300-400mg/100ml of blood
Unconsciousness, coma and death
