Understanding Drug Addiction

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Questions and Answers

What is drug addiction?

A severe form of substance use disorder characterized by compulsive drug seeking and use despite adverse consequences. It's considered a brain disorder due to functional changes in brain circuits that persist even after stopping drug use.

What are some examples of psychostimulants?

Nicotine, cocaine, methamphetamines, amphetamines, methylphenidate, and cathinone.

What is the defining feature of SUDs according to the DSM-5?

A cluster of cognitive, behavioral, and physiological symptoms.

What are the two main categories of hallucinogens?

Classic hallucinogens and dissociative hallucinogens. Signup and view all the answers

Which of the following is NOT a type of abused drug?

Antibiotics (B) Signup and view all the answers

The Schedule 1 DEA drugs have the lowest potential for abuse.

False (B) Signup and view all the answers

Which of the following is a defining feature of psychological addiction?

Compulsive drug seeking (C) Signup and view all the answers

Which of the following is NOT a mechanism of action for psychostimulants?

GABA receptor agonism (C) Signup and view all the answers

What is the primary mechanism of action of ethanol?

Ethanol blocks ionotropic glutamate receptors and increases GABAa receptor functioning. Signup and view all the answers

Explain the mechanism of action of opioids.

Opioids activate mu-opioid receptors expressed in GABAergic neurons, inhibiting their activity. Signup and view all the answers

Describe the two main dopaminergic pathways linked to addiction.

The mesolimbic pathway connects the ventral tegmental area (VTA) to the ventral striatum, while the mesocortical pathway connects the VTA to the prefrontal cortex. Signup and view all the answers

What is the role of the ventral striatum in addiction?

The ventral striatum, specifically the nucleus accumbens, is associated with reward, motivation, and the experience of pleasure. It plays a key role in the rewarding effects of substances and in the development of addiction. Signup and view all the answers

What is the role of the prefrontal cortex in addiction?

The prefrontal cortex is involved in executive function, goal-directed behavior, and inhibitory control. It plays a critical role in the decision-making processes related to substance use and in controlling impulsive behaviors associated with addiction. Signup and view all the answers

What are the three steps of the addiction cycle?

The addiction cycle consists of binge/intoxication, withdrawal/negative affect, and preoccupation/anticipation. Signup and view all the answers

What brain region is primarily involved in the preoccupation/anticipation stage of the addiction cycle?

The prefrontal cortex (PFC) is heavily involved in this stage, particularly its role in executive function and craving for the substance. Signup and view all the answers

What are the two sources of the negative state of withdrawal?

<ol> <li>Diminished activation of the reward system (reduced dopamine release), and 2. Activation of the brain stress system (extended amygdala).</li> </ol> Signup and view all the answers

What is the dopamine depletion hypothesis of addiction?

Depletion of dopamine levels in the brain due to drug use leads to dysphoria. The individual then uses drugs to replenish these levels, perpetuating the cycle of seeking and using drugs to maintain a somewhat normal level of dopamine, but ultimately causing a cycle of drug seeking behavior and potentially leading to addiction. Signup and view all the answers

Explain the difference between the 'GO' and 'STOP' systems in the prefrontal cortex.

The 'GO' system, including the anterior cingulate cortex and dorsolateral prefrontal cortex, is associated with goal-directed behavior and drives substance use. The 'STOP' system, encompassing the ventrolateral prefrontal cortex and orbitofrontal cortex, inhibits the 'GO' system and helps control impulsive behaviors. In addiction, the 'STOP' system becomes hypofunctional, leading to a decrease in impulse control and an increase in compulsive substance seeking. Signup and view all the answers

Describe the role of dopamine in the nucleus accumbens in the context of addiction.

Dopamine plays a significant role in the nucleus accumbens, the brain's reward center. When an individual is exposed to cues associated with a rewarding substance, dopamine levels in the NAc surge, leading to a feeling of anticipation and craving. This dopamine activity is crucial for the development of incentive salience, where the cues become powerful motivators for drug seeking. Signup and view all the answers

What are the two main types of receptors present on medium spiny neurons (MSNs) in the nucleus accumbens?

D1-like receptors and D2-like receptors. Signup and view all the answers

What is the difference in function between D1Rs and D2Rs in the NAc?

D1Rs are primarily involved in anticipation and expectation of reward, while D2Rs are associated with motivation for procurement. D1Rs are mainly activated when dopamine levels peak, while D2Rs have a higher affinity for dopamine binding, leading to a longer-lasting and persistent effect after DA levels subside. Signup and view all the answers

How does dopamine signaling differ in response to natural reinforcers versus drugs of abuse?

For natural reinforcers, dopamine signals triggered by conditioned stimuli drive motivation to obtain the reward, but dopamine firing stops after the reward is consumed. In contrast, drugs of abuse continue increasing dopamine release during consumption. This sustained dopamine release in the NAc triggers intense craving even during drug consumption, further reinforcing the motivation to continue using the drug. Signup and view all the answers

What is the purpose of the short access model in addiction research?

The short access model helps determine how animals respond to various doses of a particular drug. Researchers can administer different doses and observe the animals' behavior to assess how tolerance to the drug develops in relation to those doses. Signup and view all the answers

What is the long access model used to model in addiction research?

The long access model is specifically designed to capture the transition from recreational drug use to addictive-like behaviors. It enables researchers to study escalation of drug consumption, leading to compulsive drug-seeking behavior, which more closely mirrors the progression of addiction in humans. Signup and view all the answers

What is the purpose of the progressive ratio in addiction research?

The progressive ratio is used to measure an animal's motivation for a particular reward, in this case, a drug. This method increases the response requirement for the drug delivery, and the 'breakpoint' is reached when the animal stops responding for the reward, indicating how hard they are willing to work for the drug. Signup and view all the answers

What does the 'extinction-reinstatement' model of relapse test?

This model investigates distinct aspects of relapse: (1) drug-induced reinstatement, where exposure to the drug itself increases the likelihood of relapse, and (2) cue-induced reinstatement, where exposure to cues associated with drug use triggers relapse. This model demonstrates that even if a treatment successfully blocks drug-induced reinstatement, it might not necessarily be effective in reducing the impact of drug-paired stimuli and withdrawal-induced relapse. Signup and view all the answers

Describe the concept of 'compulsive drug seeking' and how it is modeled in animals.

Compulsive drug seeking is characterized by continued drug use despite negative consequences. In animal models, researchers employ drug self-administration procedures where the delivery of the drug is coupled with a punisher, such as a foot shock. This procedure simulates the real-world situation where people continue using drugs despite the negative consequences they may experience, helping researchers understand the persistent nature of addiction. Signup and view all the answers

What is a 'breakpoint' in the context of drug self-administration?

The breakpoint is the response requirement at which an animal stops responding for the drug reward. It signifies how hard an animal is willing to work to receive the drug, indicating the strength of their motivation for obtaining the drug. Signup and view all the answers

Drug addiction is a primary brain disorder that primarily affects the brain and not the body.

False (B) Signup and view all the answers

Flashcards

Drug addiction

A serious biomedical disorder characterized by a compulsive urge to use a substance, despite negative consequences.

Substance use disorders (SUDs)

Actions that individuals continuously perform despite potential negative consequences, often related to substance use.

SUDs are classified as psychiatric disorders in...

The Diagnostic and Statistical Manual of Mental Disorders (DSM) and the International Classification of Diseases (ICD) classify SUDs as psychiatric disorders.