neurobiology of addiction

Question 1

what is the ICD-10 criteria of dependence

Answer 1

-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

Question 2

what is ICD 11 criteria for gaming disorder

Answer 2

-impaired control over gaming,
-increasing priority given to gaming over other activities to the extent that gaming takes precedence over other interests and daily activities,
-and continuation or escalation of gaming despite the occurrence of negative consequences

must be evident for at least 12 months

Question 3

what is the pathway of wanting

Answer 3

mesolimbic pathway

Question 4

what is the dopaminergic activity in the mesolimbic pathway

Answer 4

-is a motivating signal
-incentivises behaviour
-is involved in normal pleasurable experiences

Question 5

role of the pre-frontal cortex

Answer 5

Helps intention guide 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

Question 6

what do addictive drugs do to the PFC

Answer 6

provide a potent signal that disrupts normal dopamine-related learning in the PFC

Question 7

what is the orbito-frontal cortex role in addiction

Answer 7

-Provides internal representations of the saliency of events and assigns values to them
-Key creator of motivation to act
-Addicts show increased activation of OFC when presented with drug cues
-Hyperactivity correlates with self reported drug cravings following exposure to cues
-Overall changes in OFC persist into abstinence

Question 8

what circuits are involved in drug abuse and addiction

Answer 8

Question 9

how do genetics affect addiction

Answer 9

-40-60% of the risk factors are due to genetics
-may affect the way we respond to drugs metabolically
-behavioural traits that predispose us to take drugs
-how rewarding we find drug taking
-receptor levels (low DRD2 = higher risk)

Question 10

how can stress cause addiction

Answer 10

-Acute stress triggers release of dopamine in the neural reward pathway.
-Chronic stress leads to dampening of dopaminerigc activity through down regulation of D receptors.
-This reduces sensitivity to normal rewards
-Encourages exposure to highly rewarding behaviours
-Rapid increase in stress can motivate drug seeking in dependent individuals.