Addiction Flashcards
(57 cards)
What is the moral model of addiction
The idea that addicts use drugs through choice with no regard for the consequences of the drug use
This model leads to the criminal justice approach to management of drug addiction through prisons etc.
The individual is the cause
What is the medical model of addiction
The idea that being addicted to drugs and repeatedly taking them causes neurobiological changes in the brain which decrease the persons ability to exercise free choice
This leads to more compassionate care and better treatment
What are the symptoms of substance dependence
A strong desire to take the substance Difficulties in controlling substance use A physiological withdrawal state Tolerance Neglect of alternative pleasures Persistence despite evidence of harm
Which NT is the motivating signal in the reward pathway
Dopamine
The more that is released, the more a person is incentivised to perform that behaviour
How do drugs trigger the reward pathway
They all cause dopamine release by acting on a variety of targets in the nucleus accumbens
Cocaine and amphetamines act on dopamine receptors which is why they have such significant effects
What is meant by tolerance to reward
The dopamine pathway is overstimulated (by drug use) and is downregulated
This means that normal pleasure activities will no longer be enough to trigger the pathway
This leads to continued drug use to cause pleasure
How long does tolerance to reward last
The changes in the dopamine pathway will persist for an extend period even with prolonged abstinence
This leads to high relapse rates
What drives drug addiction
Initially it is driven by the reward pathway - positive reinforcement
Then it becomes a thirst - negative reinforcement
What is the function of the prefrontal cortex
It’s involved in executive function - making sound decisions and keeping emotions and impulses under control
Last part of the brain to develop - still developing into 20s
How is the prefrontal cortex involved in addiction
It is often much less developed in those who are addicted
Could be genetic or caused by substance use before it is developed
Makes it harder to stop drugs in the long term - less executive functioning
How is the hippocampus involved in drug behaviour
It is important in memory and learning
Learned drug/substance associated such as rolling a cigarette will cue a state of craving by stimulating the dopamine pathway
How is the orbito-frontal cortex involved in drug use
It is the key creator of motivation to act
Highly associated with cravings
Does substance use have a genetic component
Yes = 40-60% of risk is due to genetics
May affect how the body responds to drugs, the dopamine response and behavioural traits
How does stress affect the dopamine pathway
Acute stress leads to dopamine release within the neural reward pathways
Chronic stress leads to downregulation of the receptors which reduces sensitivity to normal rewards - this encourages exposure to highly rewarding behaviour such as drug taking
What is incentive salience
When you attribute want to a stimulus
The reward pathway is involved
Describe the current trend in drug deaths
Numbers are rising
List the effects of heroin (and other opiates)
Euphoria Analgesia Constipation Reduced conscious level Respiratory depression Hypotension and bradycardia Pupillary constriction Tolerance develops with repeated use
How long does it take for withdrawal to start
Typically occurs within 6-8 hours
Describe drug tolerance
As you contribute to use drugs you become tolerant to that dose
Usual dose no longer has an effect and so the person takes more - cycle
What often causes a drug death
People try to come off the drug and their tolerance drops
If they re-take their usual dose which is now far too high
Describe the symptoms of opiate withdrawal
Dysphoria and cravings Agitation Tachycardia and hypertension Piloerection Diarrhoea, nausea and vomiting Dilated pupils Joint pains Yawning (constant) Runny nose (rhinorrhoea) and watery eyes (Lacrimation)
Which route of administration of heroin gives a stronger affect
Injecting it
Stronger effect and often cheaper
What infections can be caused by IV drug use
Local: cellulitis, abscess, thrombophlebitis, necrotising fasciitis
Distant: e.g. infective endocarditis,
Systemic: Hep B, HIV, Hep C
Do opioids cause psychosis
No
Cannabis, hallucinogens and alcohol are much more likely to do this
