adictia Flashcards
What is addiction?
The compulsive seeking, and then obtaining of a substance or object.
it is a dependency because the way people behave is dominated by the idea of obtaining the object of addiction.
Why does addiction occur?
Drugs’ cumulative use disrupts neurotransmission.
What are the 6 features of addiction?
- Salience: the object of addiction dominated our thoughts and actions.
- Tolerance: increasing the dose
- Craving
- Withdrawal symptoms: changes in mood
- Conflict: between the addicted and other people
- Relapse: use of drugs after trying to stop
How are genes involved in addiction?
Children of alcoholics have 4-fold increase in the likelihood of becoming alcoholics themselves compared to children born to non-alcoholics
How is environment involved in addiction?
The sight of a place related to drugs can release dopamine in the pleasure pathway.
Then the brain seeks to obtain the drug - this is craving.
How drugs alter neurotransmission?
Some drugs mimic neurotransmitters.
Heroin chemically resembles the brain’s natural opioids, which control pain, mood, hunger and thirst.
Heroin stimulate many more receptors than the brain natural opioids.
This results in massive opioid activity, producing a euphoric feeling.
How else do drugs alter neutransmitters?
Some drugs intervene with the sending and receiving of neurotransmitters.
Cocaine attaches to dopamine transporters, blocking them. This means dopamine can’t be reabsorbed into the sending cell.
Extra dopamine in the synapse
Leads to a more intense and longer-lasting pleasure or reward signal than would naturally occur.
what is the early phase of drug experimentation
What is the wanting-and-liking theory?
Wanting and liking rely on 2 different brain systems:
Wanting: mesolimbic pathways
Liking: brainstem
Wanting and liking a drug go in opposite directions with repeated use.
what are the medium-longer term changes
What is drug tolerence?
Adjustments to compensate for drug-induced increases in the intensity of NT signalling.
What are the neural changes that occur?
The brain is rewired
In some brain regions, connections between neurones are pruned back.
In others, neurones form more connections.
E.g.: ecstasy damages axons that release serotonin so serotonin neurotransmission is disrupted
Which 3 main types of NT play an important role in addiction?
Dopamine, serotonin and noradrenaline
what is the role of serotonin
lack of serotonin can lead to depression
people with low sero are more likely to get addicted to drugs because it leads to a temporary increase in serotonin levels
role of dopamine
drugs block re-uptake
dopamine accumulates in the synapse and stimulates receptors to make addict feel good
