Mechanisms of Addiction
What is addiction?
Addiction is a chronic brain disorder that affects the body through physical and psychological dependence.
Intentional, regular use of substances like opioids, alcohol, tobacco, or other drugs becomes an addiction when a person can no longer control his or her use despite negative consequences such as loss of control and harm to themselves or others.
What is the addictive ingredient in alcoholic beverages that has both stimulant and depressant effects?
Ethanol
What natural form of opioid, produced by the body, helps control pain and emotion?
Endorphins
What substance in tobacco is highly addictive but does not directly cause cancer?
(Bonus: what part of tobacco does lead to cancer?)
Nicotine
(The thousands of chemicals in tobacco, about 70 are known to be carcinogenic)
What are 1) tolerance and 2) withdrawal?
1) Tolerance is when a person’s body becomes “used to” a drug and requires more of it to experience the same effect.
2) Withdrawal is when lack of a drug causes the body to react with unpleasant or life-threatening physical symptoms.
What are the primary symptoms associated with alcohol use disorder, and which region of the brain is primarily damaged, leading to these effects?
An unsteady gait, tremors, and slurred speech (due to damage in the cerebellum)
What synthetic opioid is more powerful than others, often used to treat severe pain, but is also abused?
Fentanyl
To which receptors does nicotine bind, triggering the release of dopamine and adrenaline?
Nicotinic acetylcholine receptors
Which neurotransmitter is mainly involved in the pleasure-producing, brain "reward" system?
(Bonus points: what is the reward system called?)
Dopamine
(The limbic system)
What are the two factors that both contribute to the risk of developing alcohol addiction.
Given that not all people who choose to drink become addicted to alcohol, it is clear that both genetic and environmental factors contribute to alcoholism.
What type of medication do most current heroin users report as the starting point for their addiction?
Prescription pain medications
What percentage of lung cancer deaths is attributable to smoking?
90%
During which life stages do social environmental factors have the strongest influence on drug-taking behavior?
Childhood and adolescence.
How many Americans are estimated to have an alcohol use disorder?
About 15 million Americans
How does naloxone work to reverse opioid overdoses?
By binding to opioid receptors without producing a biological effect (which prevents an opioid molecule from binding)
What stimulant property of nicotine contributes to increased attention and memory?
Dopamine release
What internal and external factors significantly influence vulnerability to addiction?
(Bonus question: What are the two types of genes commonly linked to addiction?)
Genetic factors and the social environment
(Genes affecting brain circuits and genes affecting drug metabolism)
How does ethanol affect 1) gamma-aminobutyric acid (GABA) receptors in the brain and 2) N-methyl-D-aspartate (NMDA) receptors?
It drives the brain’s inhibitory system, calming anxiety, weakening muscles, and delaying reaction time.
Ethanol also blocks the N-methyl-D-aspartate (NMDA) type of glutamate receptors, which alter mood and impair memory.
Which drug stimulates opioid receptors, produces a limited high, and is safer than methadone for addiction treatment?
Buprenorphine
What FDA-approved drug mimics nicotine to help people quit smoking?
Varenicline