11 Substance Abuse

Question 1

Q: What is substance abuse?

Answer 1

A: Substance abuse refers to a chronic and excessive pattern of drug use that is not for therapeutic purposes.

Question 2

Q: What does addiction or dependence involve?

Answer 2

A: Addiction or dependence involves being physically dependent on a drug and engaging in abusive behaviors related to its use.

Question 3

Q: What are some serious threats associated with substance abuse, particularly with drugs like cocaine?

Answer 3

A: Substance abuse poses serious threats to health, with drugs like cocaine inducing psychotic behavior and the use of designer drugs carrying risks due to being untested and potentially contaminated.

Question 4

Q: What are some risks associated with intravenous drug use?

Answer 4

A: Intravenous drug use increases the risk of contracting infectious diseases, overdose, and death.

Question 5

Q: What are some health consequences of alcohol abuse?

Answer 5

A: Alcohol abuse can lead to cirrhosis of the liver, an increased risk of heart disease and stroke, and conditions like Korakoff’s syndrome.

Question 6

Q: What health risks are associated with smoking tobacco?

Answer 6

A: Smoking tobacco increases the risk of many cancers, heart disease, and stroke.

Question 7

Q: What is positive reinforcement in the context of drug use?

Answer 7

A: Positive reinforcement involves the addition of a reinforcing stimulus following a behavior, making it more likely for the behavior to occur again. In drug use, individuals are reinforced by the immediate effects of the drug.

Question 8

Q: How do drug users demonstrate preference between heroin and morphine?

Answer 8

A: Drug users often prefer heroin to morphine due to the quicker effect of heroin. This preference is based on the principle that reinforcing stimuli have greater effects when they occur immediately after behavior.

Question 9

Q: What are the neural mechanisms underlying drug addiction?

Answer 9

A: Drug addiction involves the release of dopamine in the nucleus accumbens, initiating the process of addiction in the mesolimbic dopaminergic system. Long-term changes occur in other brain regions, starting with the ventral tegmental area (VTA), leading to increased activation of regions receiving dopaminergic input from the VTA. These synaptic changes responsible for compulsive behaviors occur only after continued drug use. Additionally, important changes occur in the dorsal striatum, which is part of the basal ganglia and plays a role in instrumental conditioning.

Question 10

Q: What is negative reinforcement in the context of drug addiction?

Answer 10

A: Negative reinforcement involves the removal of something unpleasant rather than punishment. In drug addiction, tolerance and withdrawal symptoms are examples. Tolerance refers to decreased sensitivity from continued drug use.

Question 11

Q: What are withdrawal symptoms in drug addiction?

Answer 11

A: Withdrawal symptoms are the opposite effects of the drug experienced when its use is discontinued. The body may compensate for disturbed homeostatic mechanisms, leading to symptoms such as anxiety, nausea, and tremors.

Question 12

Q: How do withdrawal symptoms potentially maintain addiction?

Answer 12

A: Withdrawal symptoms can maintain addiction through negative reinforcement. The removal of these unpleasant symptoms by taking the drug again reinforces the behavior, making it more likely to occur in the future.

Question 13

Q: What are cravings in the context of drug addiction?

Answer 13

A: Cravings are intense desires to use drugs and can occur after long periods of abstinence. They may be due to long-lasting changes in the brain and can be triggered by drug-related stimuli.

Question 14

Q: How are cravings and relapse linked to attentional bias?

Answer 14

A: Cravings and relapse are associated with attentional bias, which involves a heightened focus on drug-related stimuli. This cognitive process can be triggered by cues associated with drug use, leading to increased desire for the drug and a higher risk of relapse.

Question 15

Q: What role does dopamine play in drug cravings and relapse?

Answer 15

A: Dopamine plays a crucial role in drug cravings and relapse. Drug-related stimuli can lead to increased dopamine release in the brain’s reward pathways, such as the nucleus accumbens and dorsal striatum. This increased dopamine activity reinforces drug-seeking behavior and contributes to the cycle of addiction.

Question 16

Q: How does the prefrontal cortex contribute to drug cravings and relapse?

Answer 16

A: The prefrontal cortex is implicated in drug cravings and relapse due to its role in emotion regulation and inhibitory control. Dysfunction in this brain region may impair an individual’s ability to regulate cravings and resist the urge to use drugs, increasing the likelihood of relapse.

Question 17

Q: What remains debated regarding the relationship between brain abnormalities and addiction?

Answer 17

A: The exact relationship between brain abnormalities and addiction is still debated. It’s unclear whether these abnormalities predispose individuals to addiction or are a consequence of prolonged drug use. Further research is needed to elucidate this relationship.

Question 18

Q: Do abnormalities cause addiction, or vice versa?

Answer 18

A: The relationship between brain abnormalities and addiction is complex and not fully understood. It remains debated whether abnormalities in the brain predispose individuals to addiction or if addiction-related behaviors lead to changes in brain function. Further research is needed to clarify this relationship.

Question 19

Q: How do opiates such as heroin affect the brain?

Answer 19

A: Opiates like heroin stimulate opioid receptors in various brain regions, leading to analgesia (pain relief), hypothermia (lowered body temperature), sedation, and reinforcement. The reinforcement effects involve the ventral tegmental area (VTA) and nucleus accumbens (NA), where opiates trigger the release of dopamine, contributing to their addictive properties.

Question 20

Q: What evidence suggests the reinforcing effects of opiates are produced by activation of neurons in the VTA and NA?

Answer 20

A: Studies, such as Wise et al. (1995), have shown that opiate-related stimuli trigger a significant increase in dopamine levels in the nucleus accumbens (NA) of rats. Additionally, rats self-administer opiates directly into the NA and VTA, indicating that the reinforcing effects of opiates are associated with the activation of neurons in these brain regions.

Question 21

Q: How do stimulant drugs like cocaine and amphetamine affect the brain?

Answer 21

A: Stimulant drugs like cocaine and amphetamine exert their effects by increasing dopamine levels in the brain. Cocaine blocks the reuptake of dopamine by deactivating dopamine transporter proteins, while amphetamine inhibits dopamine reuptake and directly stimulates its release from nerve terminals. These actions contribute to the rewarding and addictive properties of these drugs.

Question 22

Q: What evidence suggests the addictive potential of cocaine and amphetamine?

Answer 22

A: Research by Bozarth and Wise indicated that rats self-administering cocaine were three times more likely to die than those self-administering heroin, suggesting a high addictive potential for cocaine. Furthermore, blocking dopamine receptors or destroying dopaminergic terminals in the nucleus accumbens (NA) significantly reduces the reinforcing effects of stimulant drugs, supporting their role in addiction.

Question 23

Q: What is the impact of nicotine on the brain?

Answer 23

A: Nicotine stimulates nicotinic acetylcholine receptors (nAChRs) and is associated with the release of dopamine in the nucleus accumbens (NA), reinforcing addictive behavior. Animal studies have also shown that animals self-administer nicotine, indicating its high addictive potential.

Question 24

Q: How does damage to the insula affect smoking addiction?

Answer 24

A: Research by Naqvi et al. (2007) found that individuals with damage to the insula were significantly more likely to experience disruptions in smoking addiction compared to those without insula damage. Despite no difference in quit rates between the two groups, those with insula damage showed a higher likelihood of having disrupted smoking addiction, suggesting the insula’s role in the addiction process.

Question 25

Q: What are the effects of alcohol on the brain and behavior?

Answer 25

A: Alcohol has various effects on behavior, including mild euphoria, anxiolytic (anxiety-reducing) effects, disinhibition, and alcohol myopia, where individuals respond to immediate cues while ignoring remote consequences. It increases activity in dopaminergic neurons of the mesolimbic system and acts as an indirect antagonist at NMDA receptors and an indirect agonist at GABAA receptors.

Question 26

Q: How does alcohol withdrawal contribute to potential health risks?

Answer 26

A: Withdrawal from alcohol can lead to increased sensitivity of NMDA receptors, potentially triggering seizures and convulsions, which can be fatal. Drugs that block NMDA receptors have been shown to prevent seizures in mice and may be used to manage alcohol withdrawal symptoms in humans.

Question 27

Q: What is Korsakoff syndrome, and how is it related to alcoholism?

Answer 27

A: Korsakoff syndrome is a condition seen in alcoholics who are malnourished, characterized by a lack of vitamin B1 in the brain and exacerbated by the toxic effects of alcohol. It leads to damage to areas of the thalamus and mammillary bodies, which are important for encoding new memories. (Jimmie G)

Question 28

Q: What is the principal psychoactive component of cannabis?

Answer 28

A: Tetrahydrocannabinol (THC) is the principal psychoactive component of cannabis.

Question 29

Q: How do cannabinoid type 1 receptors (CB1Rs) contribute to the effects of THC?

Answer 29

A: CB1 receptors mediate most of the psychotropic effects of THC. Blocking these receptors abolishes the high typically experienced with THC consumption.

Question 30

Q: What role does THC play in stimulating dopaminergic neurons?

Answer 30

A: THC also has a stimulating effect on dopaminergic neurons, contributing to its psychoactive effects.

Question 31

Q: How do CB1 receptors influence the reinforcing effects of drugs?

Answer 31

A: CB1 receptors likely play a role in the reinforcing effects of various drugs. Blocking these receptors abolishes the reinforcing effects of cannabis, morphine, heroin, and alcohol. Additionally, drugs that block CB1 receptors, such as rimonabant, have been found to decrease the reinforcing effects of nicotine.

Question 32

Q: How do genetic and environmental factors influence drug abuse susceptibility?

Answer 32

A: Both genetic and environmental factors contribute to whether someone tries a drug and their likelihood of becoming dependent. While environmental factors may play a stronger role in drug use initiation, genetics often play a stronger role in determining susceptibility to addiction.

Question 33

Q: What did Kendler et al. (2003) find regarding the roles of genetics and environment in drug abuse?

Answer 33

A: Kendler et al. (2003) conducted interviews with 1196 male-male twin pairs and found that while environmental factors had a stronger influence on drug use initiation, genetics played a stronger role in determining susceptibility to addiction.

Question 34

Q: What proportion of vulnerability to addiction is attributed to genetics?

Answer 34

A: Approximately 40-60% of vulnerability to addiction is attributed to genetic factors.

Question 35

Q: What are some environmental factors that contribute to drug abuse susceptibility?

Answer 35

A: Environmental factors such as drug availability, low socioeconomic status (SES), high stress levels, and poor parental support can all contribute to drug abuse susceptibility.

Question 36

Q: What is the common treatment for opiate addiction, and how does it work?

Answer 36

A: Opiate addiction is commonly treated with methadone, which is an orally administered replacement drug. Methadone helps to reduce withdrawal symptoms and cravings associated with opiate addiction.

Question 37

Q: What is buprenorphine, and how is it used in the treatment of opiate addiction?

Answer 37

A: Buprenorphine is a newer drug used in the treatment of opiate addiction. It works by blocking the effects of opiates and producing only a weak opiate effect itself. Buprenorphine can help reduce cravings and withdrawal symptoms in individuals recovering from opiate addiction.

Question 38

Q: What is emphasized regarding the treatment of opiate addiction?

Answer 38

A: A combination of treatments is often emphasized as the most effective approach for treating opiate addiction. Additionally, while treatment can be effective, willpower and commitment to recovery are significant factors in achieving success.