Addiction Worksheet Flashcards
What is the equation for the twin pair probandwise concordance rate
(2C)/(2C+X)
What does C represent for probandwise concordance rate
Concordant pair - matching
What does D represent for probandwise concordance rate
Discordant pair - mismatch
A probandwise concordance rate that is higher in MZ twins than DZ twins indicates…
Genetic influence
A probandwise concordance rate that is higher in DZ twins than MZ twins indicates…
Environmental influence
What were the results of the twin-pair concordance study on alcoholism
- MZ had a higher rate than DZ indicating a genetic link
- Males had a higher rate overall compared to females
Describe the pathway of alcohol metabolism
Alcohol is metabolized into acetaldehyde with the enzyme alcohol dehydrogenase and then acetaldehyde is broken down to acetic acid via the enzyme acetaldehyde dehydrogenase
If alcohol dehydrogenase works faster, what is the impact?
decrease blood alcohol levels and increased acetaldehyde
-adverse reaction to alcohol, unlikely to abuse
If alcohol dehydrogenase works slower, what is the impact?
Increased blood alcohol levels and decreased acetaldehyde
-Feel alcohol effects more than normal
If acetaldehyde dehydrogenase works faster, what is the impact
decreased acetaldehyde
-less toxic response, increased risk of becoming an alcoholic
If acetaldehyde dehydrogenase works slower, what is the impact?
Same blood alcohol level and increased acetaldehyde
- increased toxic response
What area of the brain does the reward pathway originate in
ventral tegmental area
Where do the cells in the reward pathway extend from and where do they synapse and what is released
Extend form the medial forebrain bundle and synapse in the nucleus accumbens and release dopamine
Rank the following in order of most dopamine released to least amount of dopamine released;
Cocaine, meth, nicotine, cannabis, psilocybin and chocolate
Meth, cocaine, nicotine, cannabis, chocolate, psilocybin
What happens to the brain when an addict sees a drug cue?
increase activation of the anterior cingulate cortex representing the expectation of emotional pleasure
What happens to the body when an addict sees a drug cue?
Physiological counter response to the drug
What are the 4 Cs of addiction
Cravings
Loss of control in amount or frequency of use
Compulsion to use
Use despite consequences
What is the mechanism behind compulsion to use as an addict?
- Use of drugs causes a reduction in dopamine receptors in the reward system
-lower levels of basal pleasure cause addicts to compulsively use the drug to feel good
What is the mechanism behind loss of control and use despite consequences?
- Reduced activation of the frontal lobe
-frontal and prefrontal cortices are needed for rational thinking and empathy
How does adolescents risk taking behavior differ from adults
Adolescents are more susceptible to risk taking behavior because of their under-developed frontal lobe
What is the mechanism behind cravings
activation of the reward system in anticipation of the drug
-through conditioning we can learn to associate cues with the administration of a drug
-Cues activate ACC and cause cravings
Does addiction run in families?
Yes
-children of addicts are at increased risk of becoming addicts themselves
-alcoholism is more likely to co-occur in MZ twins than DZ twins, suggesting a genetic link
Can we predict abuse according to how an individual responds to drugs?
Yes
-Low responders to alcohol are more likely to become alcoholics than high responders
-This could explain individual differences in why some children of alcoholics become alcoholics themselves whereas others do not
How do genetics influence susceptibility to addiction?
- The ALDH2 gene codes for low vs high responders
- ALDH22/2 genotype is protective of alcohol abuse by inducing high responder phenotype
Affects of weed
Bad for mental health
-THC is addictive
-elevates dopamine to supernatural levels
-chronic use blunts the release of dopamine to naturally rewarding stimuli
-causing drug dependency
-cannabis use is associated with schizophrenia psychosis
Affects of magic mushrooms
-mimics serotonin to enhance mood
-minimal effect on dopamine
-promising therapy for drug-resistant depression
