Addiction Flashcards
What is the ICD-10 criteria of 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
What is a widely used test for alcohol dependence?
CAGE: Cut-down Annoyed Guilty Eye-opener
Describe dopaminergic activity in the mesolimbic pathway
A motivating signal
Incentivises behaviour
Is involved in normal pleasurable experiences
What suggests a tolerance to reward develops?
fMRI study of gambling addicts vs non-addicts
Non-addicts had increased blood flow to striatum upon winning, addicts did not
What decreased dopamine D2 receptor functionality?
Addiction
Why does tolerance occur and why does it persist?
Due to repeated dopamine release, dopamine receptors down regulate.
Threshold for rewards during abstinence is thus increased
Normal pleasurable experiences don`t evoke adequate reward response
These changes persist despite prolonged abstinence from substance abuse
What does the orbito-frontal cortex do?
Provides internal representations of the saliency of events and assigns values to them
Key creator of motivation to act
What do addicts show increased activation of when presented with drug cues?
OFC
What is the role of the PFC?
Helps intention good behaviour
Modulates the powerful effects of the reward pathway
Sets goals, focuses attention
Makes sound decisions
Keeps emotions and impulses under control to achieve long term goals
Do frontal lobe areas that mediate executive functioning mature earlier or later than limbic systems?
Later
Describe frontal lobe maturation
Progresses in a back-to-front direction, beginning in the primary motor cortex and spreading anteriorly over the superior and inferior frontal gyri, with the prefrontal cortex developing last
What signal do addictive drugs provide?
Potent signal that disrupts normal dopamine related learning in the PFC
What are the effects of dopamine release?
Ability to update information within the PFC
Ability to select new goals
The ability to avoid compulsive repetition of a behaviour
What are the hippocampus, striatum and amygdala critical in?
Acquisition, consolidation and expression of drug stimulus learning
What is the most heritable complex psychiatric condition?
Addiction
