Ch5: Substance Use & Addictive Disorders Flashcards
Two Theories of Addiction Disease
1) Predisposition theories: people either are born with the disease or acquire it at some time before they begin abusing the drug
2) Exposure theories: addiction is a disease that is caused by repeated exposure to the drrug
Dependence Model of Drug Abuse
Dependence means both:
1) The state in which a drug produces physical dependence (i.e., withdrawal symptoms occur when the drug is stopped)
2) The compulsive self-administration of a drug (i.e., addiction)
Psychological Dependence
Expanded the dependence model by assuming that drugs (such as marijuana that don’t cause physical withdrawal) caused unobservable psychological withdrawal symptoms.
Some sort of psychological, as opposed to physical, withdrawal symptoms that are so distressing that people are highly motivated to avoid them by using the drug.
Positive Reinforcement Model of Drug Taking
Drugs are self-administered, at least initially, because they act as positive reinforcers.
Eg. To show that an infusion of a drug is acting as a positive reinforcer for lever pressing, must show that the frequency of lever pressing will increase if it is reliably followed by an infusion of the drug, and will decrease when it is no longer followed by the drrug
Problems with the Positive Reinforcement Model
1) Positive reinforcement paradox: how does it explain addiction’s excessive/self-destructive behaviour?
Controls behaviour because positive effects are immediately experienced after behaviour, whereas punishing and painful effects are delayed. Operant conditioning - if reinforcer is delayed, its ability to control behaviour is diminished.
2) Circularity: circular explanation of drug use - drug is positive reinforcer bc it increases a behaviour upon which it is contingent.
Must define positive reinforcement in something other than behaviour.
Factors that alter the reinforcing value of a drug
- Different drugs: drugs vary in their capacity to act as positive reinforcers - abuse potential
- Dose of drug
- Genetic differences
- Relief of unpleasant symptoms: drugs have therapeutic effects have enhanced reinforcing value in people with the disorder (eg. alcohol used to relieve depression)
- Task demands: expected demands of the situation (eg. choose not to drink and drive)
- Stress & other deprivations (eg. hunger)
- Previous experience with same or other drug
- Withdrawal
- Extended access
- Priming or reinstatement
- Conditioned reinforcement
- Second-order schedules
Motivation Control System
Reinforcement system that stimulates behaviour by stimulating the motor loop in response to internal homeostatic input (eg hunger).
Behaviour is directed by sensory input and by memory of the outcome of past behaviours stored in learning & memory system.
Motor behaviour is directed by sensory input to the thalamus, which is compared to past experiences in learning & memory system. Then goes into cortex. This then activates the reinforcement system.
Activation-sensorimotor Hypothesis
Dopamine mediates general arousal, physical effort and motor activity.
Reward Learning Hypotheses of Dopamine
Dopamine is used in operantly conditioned response-reward actions, classically conditioned stimulus-reward associations, and coding of predictions about reward availability based on the presence of conditioned stimuli.
Mesolimbic Dopamine System - 2 roles in motivating behaviour
1) General activation: pushing behaviour without any general direction
2) Incentive salience: direct that behaviour toward a particular goal
D: cognitive process that confers a “desire” or “want” attribute, which includes a motivational component, to a rewarding stimulus
Incentive Sensitization Theory of Addiction
Explains drug craving (D: the manifestation of incentive salience toward drug-associated stimuli).
The incentive motivational effects of drugs & their cues become stronger (i.e., sensitized) with repeated exposure due to increased activity of the mesolimbic dopamine system. Thus, exposure to these stimuli can cause extreme incentive motivation (or craving) that can last for years, even into recovery.
Hedonic, Neurobiological/Psychological Dependence Model of Addiction
Balance between the activity of brain reward systems and the recruitment of anti-reward systems that results from recurrent drug use.
Allostatic Process
Spiraling cycle of reward/anti-reward system dysregulation.