Module 1 Flashcards
(43 cards)
By what is addiction characterized?
Compulsive drug seeking, continued use, long-lasting brain changes
DSM-5 criteria for Substance Use Disorder (SUD) (11)
2 or more, in a year
1. Larger amounts/longer period than intended
2. unsuccessful efforts to cut down
3. A lot of time in obtaining/using/recovering
4. Craving
5. Not meeting obligations
6. Social/interpersonal problems
7. Activities given up
8. Physically hazardous
9. Taken despite recurrent physical/psychological problem
10. Tolerance
11. Withdrawal
Severity scale of DSM-5 criteria SUD
- Mild: 2-3
- Moderate: 4-5
- Severe: 6+
Categories of DSM-5 symptoms (4)
loss of control, strain to interpersonal life, hazardous use, pharmacologic effects.
What categories of substances are there and what do they have in common?
Sedatives, stimulants, psychedelics: (in)directly result in a release of dopamine (DA) in the nucleus accumbens (NAcc).
What does the anticipation of a reward do?
Leads to the release of DA, especially from the NAcc in the mesolimbic pathway.
Who are less sensitive to natural rewards (as opposed to substance rewards)?
People with addiction, people with a chronic deficiency of DA D2 receptors in the NAcc.
Tolerance + what risk does this create?
Drug administered chronically>reduction of effect>more needed. Creates the risk of overdose.
Withdrawal+ what can this result in?
Symptoms in abstinence after prolonged use. Can result in continued use when liking (positive reinforcement) has gone, to avoid withdrawal (negative reinforcement).
Liking vs. wanting ?
Liking: the hedonic experience during consumption of a substance.
Wanting: craving, not necessarily consciously, triggered by drug-associated cues.
Risk factors for SUD?
- Lack of parental supervision/attachment
- Substance abuse in family
- Lower SES
- Certain personality traits
- Early aggressive behavior/drug use
- Mental health issues
- Peer pressure
- Poor academic achievement
- Substance available at school
- Community poverty
What are the relapse rates, even when people decide to seek treatment?
40-60%
Protective factors against SUD?
- Parental monitoring + support
- Financial stability
- Positive relationships
- Skills, self-efficacy
- Recreational activities
- Good academic achievement
- School anti-drug policies + connectedness
- Neighbourhood resources
Moral model of addiction
lack of willpower or character> leads to stigmatization
Brain disease model
The idea that addiction is a chronic, relapsing brain disease
* Hyperactive reward system + cognitive dysfunction
Mesolimbic dopamine pathway
Ventral Tegmental Area (VTA) > NAcc. Part of the striatum
Structural brain changes in addiction
- High DA levels in the NAcc are sustained
- Lower density of dopamine antagonist (DA D2) receptors in people with addiction.
What two theories are there for the explanation of structural changes in the DA system?
Homeostatic and RDS
Homeostatic account
Addiction>structural changes:
chronic overstimulation D2 receptors> downregulating the receptors> lowering DA transmission> anhedonia, dysphoria, tolerance
RDS
Reward deficiency syndrome: structural differences>addiction
* Less receptors>lower reward sensitivity>vulnerable for addiction (stronger stimuli needed)
Through what process can drug-associted stimuli elicit cravings?
Pavlovian conditioning
Cue reactivity study
Drug users are exposed to drug images + associated stimuli while in fMRI scanner> NAcc consistently activated
Single cell recording
Study neuronal activity of DA neurons in the midbrain, measured in monkeys, combined with Pavlovian learning.
* Start: bursts when food (US) is given
* End: bursts when CS happens
* Bursts when reward is received unexpectedly (prediction error)
Prediction error + DA
- Difference between anticipated and actual reward
- DA neurons act as teaching signal: signaling the brain that it should pay attention to predict the reward
