Addiction and Reward Flashcards
Addiction
Difficult to truly define, but can be defined as a problematic pattern of usage of an intoxicating substance, according to the DSM-5.
Telescoping
A term that describes the timeframe/how fast someone will go from using a substance for the first time to becoming dependent on that substance, and the impact it has on one’s body.
Studies show women tend to fall into addiction/dependence more quickly than men, even though men are more frequently addicted.
Behavioural/personality variables that increase risk of addiction.
There are three discussed.
1. Behavioural disinhibition (impulsivity, low harm-avoidance, low self restraint, antisociality, aggressiveness)
2. Stress reduction (anxious/stressed/neurotic individuals more likely to fall into addiction)
3. Reward sensitivity (is the individual sensation/reward seeking, extraverted, gregarious)
What causes addiction?
Addiction is caused by altered structure and function of the brain. It alters one’s motivations, leading to increased drug-seeking behaviour.
Addiction has nothing to do with “willpower.”
Stages of Drug Addiction
- Intoxication
- Development of dependence (withdrawal)
- Preoccupation and anticipation
Stages of Addiction
Intoxication
The first stage of addiction. The individual takes the substance, which then affects the nucleus accumbens and dorsal striatum (within the basal ganglia). All addictive drugs involve inducing some form of pleasure. All addictive drugs affect dopamine levels.
Stages of Addiction
Development of Dependence/Withdrawal
The second stage of addiction. When an addicted individual stops taking a drug they are dependent on, they will go into withdrawal, which has negative psychological and sometimes physical effects.
Withdrawal can be very severe for certain people who have been addicted a long time. For example, alcohol withdrawals for people who severely abuse the drug can include seizures, delirium and even death.
Stages of Addiction
Preoccupation and anticipation
The third stage of addiction. Substance-related environmental cues motivate people to seek out a drug and promote incentive salience (physiological motivation/cravings for a drug).
Opponent Process Theory of Drug Addiction
AKA withdrawal theory. The result of the coupling of pleasure while taking the drug and emotional symptoms associated with withdrawal. One needs to take a higher dose of a drug to get a hit (as the brain adjusts to the drug neurotransmitters), or even to get back to a “normal” baseline after becoming addicted.
Example: Caffeine blocks adenosine, if you drink too much coffee, the brain starts to make more adenosine receptors, thus now if you don’t drink coffee you will feel unusually sick and tired as you have adenosine latching onto both your original receptors and new ones produced by your body. You will also need to drink more coffee for the same effects of caffeine if you’ve drank a lot daily consistently. Note this is not a perfect example, as caffeine itself is not considered addictive.
Note: This is a theory, not the whole story. People may have their baseline go back to normal after rehab but still relapse into taking the drug.
In context of addiction & animal experiments
Operant conditioning (specifically positive reinforcement)
Positive reinforcement used to condition an animal: A neutral item is conditioned to have an association with a paired stimulus (a rat gets cocaine after pressing a lever, a rat starts pressing lever more). This also can happen organically with humans and addiction.
Definition of operant conditioning in general: A process of learning where voluntary behaviours are altered by the association of a reward or an aversive stimulus.
Incentive Salience
Motivation for rewards driven by physiological state & learned associations about a specific reward cue.
Eg. Money: Over time we learn money helps us get things we want. Money is the reward cue.
All addictive drugs directly or indirectly increase [answer] transmission.
Dopamine
Dopamine projects from the [answer] to [answer].
Ventral Tegmental Area (VTA) to Nucleus Accumbens (NAcc)
L-DOPA
Prodrug that replaces dopamine in individuals with Parkinson’s disease, reduces symptoms.
Incentive-sensitization theory
This theory distinguishes between wanting a drug (motivation to take a drug) versus liking the drug (gaining pleasure from the drug. Drugs hijack the dopamine system, increasing the motivation to take the drug due to incentive salience (eventually, sight of the drug facilitates motivation).
