Neurobiology of Addiction Flashcards
What are the ICD-10 criteria of dependence?
a strong desire to take the substance; difficulties of controlling substance use; physiological withdrawal state; tolerance; neglect of alternative pleasures; persistence despite evidence of harm
What does CAGE stand for in screening alcohol dependece?
cut-dpwn; annoyed; guilty; eye-opener
What is incentive salience?
attributing want to a rewarding stimulus
Which pathway in the brain deals with reward?
mesolimbic pathway
What makes up the mesolimbic pathway?
ventral tegmental area–nucleus accumbens–prefrontal cortex
What does dopamine release in the mesolimbic pathway lead to?
incentivises behaviour
What happens in response to overuse of the reward pathway?
tolerance to reward develops
How does tolerance to reward develop?
repeated dopamine release leads to down-regulation of dopamine receptors
What are the consequences of tolerance to reward?
threshold for rewards during abstinence is increased; normal experiences dont evoke adequate reward which persist
What drives the initial stages of drug taking?
reward- positive reinforment
Waht drives the later stages of drug taking?
negative reinforcement- becomes a thirst
What is the function of the pre-frontal cortex?
helps intenetion guide behaviour; sets goals, focuses attention; keeps emotions and impulses under control to achieve long term goals
How does cortical maturation occur?
in a baack-to-front direction
When do the frontal lobe areas mature in relation to limbic systems?
later
What are the effects of dopamine release in the PFC?
affects the ability to update information; to select new goals and aibilty to avoid compulsive repetition of a behaviour
What is delayed discounting?
a greater reward further away compared to a smaller reward sooner seems smaller due to distance away
What parts of the brain are especially important in learned drug associations?
hippocampus; striatum and amygdala- linked to the mesolimbic pathway
What is the function of orbito-frontal cortex?
provides internal representations of the saliency of events and assigns values to them- key creator of motivation
What gives you a higher genetic risk in terms of receptors to addiction?
low dopamine receptors give higher risk
Why does stress motivate drug seeking?
acute stress triggers release of dopamine in nrual reward pathway
What is the result of chronic stress in the neural reward pathway?
down-regulation of D receptors reducing sensitivity to normal rewards
