Week 2 - Neurobiology Flashcards
(56 cards)
Models of addictive behaviour - drug use models
- disease model
- physical dependence model
- positive reinforcement model
Definition of addictive behaviour
Compulsive (impaired control over use of the drug) & self-destructive (harmful consequences to user)
What year was addiction added to the DSM?
1987
Strengths of the disease model
- may make accessing treatment easier
- rules that usually govern behaviour may not apply to drug taking, since this behaviour is abnormal
- can account for individual differences in response to drugs
Limitations of the disease model
- what is the disease?
- may reduce individual responsibility for behaviour
Physical dependence model
the state in which the discontinuation or reduction of a drug would cause withdrawal symptoms
Drug administration and withdrawal effects
- repeated drug administration - body learns to adjust to drug-induced changes
- drug removes - body readjusts again (withdrawal)
- withdrawal symptoms are usually opposite symptoms incurred by drug
How can withdrawal symptoms be stopped?
by re-administering the drug, or a similar drug (cross-dependence)
Strengths of physical dependence model
compatible with disease model; plausible explanation for addiction to drugs with withdrawal effects
Limitations of physical dependence model
cannot account for:
- individual differences as well as the disease model can
- substances of addiction that show little to no withdrawal sickness
- voluntary withdrawal (despite symptoms)
How does the psychological dependence model attempt to refine the physical dependence model?
- circular reasoning
- difficult to assess outward manifestations
Positive reinforcement model
- drugs are self-administered because they act as a positive reinforcer (operant conditioning)
- drugs that are self-administered by animals even in the absence of physical dependence/withdrawal
What is a positive reinforcer?
any stimulus that increases the frequency of a behaviour it is contingent on
Limitations of positive reinforcement model
- can the positive consequences of behaviour outweigh the costs?
- circularity: drug is a positive reinforcer because of increased drug taking behaviour; then positive reinforcement cannot explain drug taking
Strengths of the positive reinforcement model
- accounts for drug-taking behaviour in absence of dependence/withdrawal
- compatible with disease/physical dependence model
- compatible with general model of reinforcement
How does classical & operant conditioning apply to drug taking?
- Reinforcing effects of drugs can be paired with other stimuli through conditioning
- an extinction phase can be demonstrated
- Responses to operant reinforcement schedules can be elicited as predicted
- responses can be elicited following priming
- response patterns to substances that act as aversive stimuli are consistent with avoidance behaviours
- a conditioned compensatory response can be demonstrated
why do positive reinforcers activate motivational circuits?
because it may increase likelihood of behaviour repeating
What does the motivational circuit rely on?
activity of neurotransmitters
Incentive salience
A strong motivation for rewarding stimuli (natural and acquired)
neuroanatomy of motivation & reinforcement
- ‘wanting’ vs ‘liking’ in reinforcement
- ‘pleasure centres’
- drugs as reinforcers
- stress & reinforcement
- addiction
- drugs alter the functioning of the motivation system & behaviour
- increase dopamine in mesolimbic dopamine system
Incentive Sensitisation Theory
with repeated administration of a drug, the reinforcing effects (incentive value) and related stimuli become sensitised.
- increased sensitisation of the dopamine response in mesolimbic dopamine system & motivation circuitry, leads to;
- increased intensive salience being acquired of the drug and associated stimuli
Drug craving
desire/urge to experience the effect(s) of a previously experienced psychoactive substance (wanting)
Strengths of the Incentive Sensitisation Theory?
- accounts for the development of addiction over time/use
- explain craving triggers (associated stimuli that have acquired incentive salience) & priming effects
Hendonic dysregulation & adaptation (HD&A) is the modern version of which model?
the physical dependence model
