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Question 1Theories, Models, and Principles of Addiction and Recovery

Which model of addiction holds that repeated drug use becomes a compulsive habit driven by progressive dysfunction of brain reward and control circuits?

  1. The moral model
  2. The social learning model
  3. The disease model Correct answer.
  4. The rational choice model

Explanation

The disease model frames addiction as a chronic, relapsing brain-based condition involving disrupted reward, motivation, and inhibitory control circuitry. It treats compulsive use as a symptom of underlying neurobiological dysfunction rather than a moral failing or a freely chosen behavior.

Question 2Theories, Models, and Principles of Addiction and Recovery

In Prochaska and DiClemente's stages-of-change model, a person who is aware of a problem and intends to act within the next month but has not yet done so is in which stage?

  1. Contemplation
  2. Precontemplation
  3. Preparation Correct answer.
  4. Maintenance

Explanation

Preparation is defined by intent to change in the near future, typically within the next 30 days, often accompanied by small initial steps. Contemplation involves awareness but no near-term commitment, while maintenance concerns sustaining gains already made.

Question 3Theories, Models, and Principles of Addiction and Recovery

A counselor works with a client using motivational interviewing and deliberately reflects the client's own reasons for change rather than arguing for them. This practice most directly reflects which principle?

  1. Rolling with resistance Correct answer.
  2. Confrontation of denial
  3. Coercive persuasion
  4. Fixed contingency contracting

Explanation

Motivational interviewing holds that arguing for change provokes resistance, so the counselor avoids direct persuasion and instead reflects and affirms the client's own change talk. Rolling with resistance keeps the therapeutic alliance collaborative rather than adversarial.

Question 4Theories, Models, and Principles of Addiction and Recovery

Which theoretical tradition explains addiction as learned behavior acquired through modeling, reinforcement, and outcome expectancies?

  1. Biological determinism
  2. Trait personality theory
  3. Psychodynamic theory
  4. Social cognitive theory Correct answer.

Explanation

Social cognitive theory, associated with Bandura, explains substance use through observational learning, self-efficacy, and anticipated outcomes of behavior. Expectancies and reinforcement contingencies are central mechanisms in this account.

Question 5Theories, Models, and Principles of Addiction and Recovery

According to the transtheoretical model, relapse is best conceptualized as which of the following?

  1. An expected event that can be re-entered at any stage Correct answer.
  2. Evidence that treatment was inappropriate
  3. A permanent return to the precontemplation stage
  4. A failure that ends the change process

Explanation

The transtheoretical model treats relapse as a normal part of cyclical change rather than a terminal outcome. Individuals commonly recycle through earlier stages after a lapse before resuming action.

Question 6Theories, Models, and Principles of Addiction and Recovery

Which concept from the disease model describes the phenomenon in which a person returns to heavy use quickly after a period of abstinence, often triggered by cues?

  1. Withdrawal
  2. Dependence
  3. Tolerance
  4. Relapse Correct answer.

Explanation

Relapse refers to the return to substance use after a period of abstinence and is a defining feature of chronic disease models. It is often precipitated by conditioned cues and stress rather than by simple choice alone.

Question 7Theories, Models, and Principles of Addiction and Recovery

A client says, 'I only drink because my friends drink, and I want to fit in.' Which theoretical perspective most directly addresses this explanation?

  1. Genetic predisposition model
  2. Neuroadaptation model
  3. Social learning and peer influence theory Correct answer.
  4. Moral failure model

Explanation

Peer modeling and social reinforcement are core constructs of social learning theory, which explains initiation and maintenance of use through social context. The client's account centers on conformity and modeling rather than biology or morality.

Question 8Theories, Models, and Principles of Addiction and Recovery

In motivational interviewing, the counselor's use of open questions, affirmations, reflections, and summaries is known by which acronym?

  1. CBT
  2. SMART
  3. OARS Correct answer.
  4. ASAM

Explanation

OARS stands for open questions, affirmations, reflections, and summaries, the core microskills used to elicit and strengthen change talk. These skills support the collaborative and evocative spirit of MI.

Question 9Theories, Models, and Principles of Addiction and Recovery

Which statement best captures the harm reduction philosophy?

  1. Abstinence must precede any other intervention.
  2. Reducing negative consequences is a legitimate goal even without abstinence. Correct answer.
  3. Clients must accept a disease label before receiving services.
  4. Substance use should be treated only as a criminal matter.

Explanation

Harm reduction prioritizes reducing harms associated with use, such as overdose or infection, without requiring abstinence as a precondition. It meets people where they are and respects incremental progress.

Question 10Theories, Models, and Principles of Addiction and Recovery

The biopsychosocial model of addiction is best described as which of the following?

  1. A theory that addiction results only from cultural norms
  2. An integration of biological, psychological, and social factors Correct answer.
  3. An explanation that addiction is caused solely by genetics
  4. A model that denies any role for neurobiology

Explanation

The biopsychosocial model integrates biological vulnerability, psychological characteristics, and social context as interacting contributors to addiction. It is a multifactorial framework rather than a single-cause explanation.

Question 11Theories, Models, and Principles of Addiction and Recovery

A client in early recovery reports strong cravings when passing a bar where they used to drink. Which classical conditioning concept best explains this reaction?

  1. Negative reinforcement
  2. Observational learning
  3. Conditioned cue reactivity Correct answer.
  4. Operant extinction

Explanation

Environmental cues repeatedly paired with drug effects acquire the ability to trigger craving and physiological responses, a phenomenon known as cue reactivity. It reflects classical conditioning of drug-associated stimuli.

Question 12Theories, Models, and Principles of Addiction and Recovery

Which of the following best describes the 'medical model' critique of purely moral explanations of addiction?

  1. It reframes addiction as a condition warranting clinical assessment and care. Correct answer.
  2. It denies that biology plays any role in addiction.
  3. It argues that moral judgments are the only valid basis for treatment.
  4. It insists that addiction is untreatable.

Explanation

The medical model reframes addiction as a health condition to be assessed and treated clinically rather than solely as a moral failing. This reframing supports access to care and reduces stigma.

Question 13Theories, Models, and Principles of Addiction and Recovery

In cognitive behavioral models of addiction, which construct most directly explains why a person with strong abstinence self-efficacy is more likely to maintain sobriety in a high-risk situation?

  1. Self-efficacy beliefs Correct answer.
  2. Cultural assimilation
  3. Physiological tolerance
  4. Genetic loading

Explanation

Within cognitive behavioral and social cognitive frameworks, self-efficacy is the belief in one's capability to execute coping behaviors in high-risk situations. Higher self-efficacy predicts better coping and lower relapse risk.

Question 14Theories, Models, and Principles of Addiction and Recovery

Which theory proposes that people continue substance use to avoid the discomfort of withdrawal, making removal of an aversive state the key driver?

  1. Negative reinforcement theory Correct answer.
  2. Labeling theory
  3. Positive reinforcement theory
  4. Expectancy theory

Explanation

Negative reinforcement explains maintenance of use as escape from or avoidance of withdrawal distress. The behavior strengthens because it removes an unpleasant physiological or emotional state.

Question 15Theories, Models, and Principles of Addiction and Recovery

A researcher argues that addiction arises because society labels certain behaviors as deviant and that this labeling shapes a person's self-concept and subsequent behavior. This argument aligns with which perspective?

  1. Behavioral economics
  2. Neuroadaptation theory
  3. Labeling theory Correct answer.
  4. Attachment theory

Explanation

Labeling theory holds that societal reactions and the application of deviant labels can shape identity and entrench behavior. It focuses on social definition processes rather than neurobiology or economics.

Question 16Theories, Models, and Principles of Addiction and Recovery

Which of the following is the central premise of behavioral economics as applied to addiction?

  1. Substance use reflects a shift in the relative value of drug versus nondrug reinforcers. Correct answer.
  2. Addiction is driven by a fixed biological trait.
  3. Addiction is entirely determined by cultural norms.
  4. Addiction is caused by unresolved childhood conflict.

Explanation

Behavioral economics frames addiction as a choice process in which the reinforcing value of a substance rises relative to alternative reinforcers, often described as steep delay discounting and reinforcer imbalance. Increasing access to nondrug alternatives reduces use.

Question 17Theories, Models, and Principles of Addiction and Recovery

Which relapse prevention model emphasizes the role of high-risk situations, coping responses, and the abstinence violation effect?

  1. Erikson's psychosocial stage model
  2. Kohlberg's moral development model
  3. Skinner's radical behaviorism
  4. Marlatt and Gordon's relapse prevention model Correct answer.

Explanation

Marlatt and Gordon's cognitive behavioral relapse prevention model identifies high-risk situations, coping skills, and the abstinence violation effect as determinants of lapse versus relapse. It distinguishes a single lapse from a full return to problematic use.

Question 18Theories, Models, and Principles of Addiction and Recovery

The 'abstinence violation effect' refers to which of the following?

  1. The tolerance that develops after repeated dosing
  2. The legal consequences of driving while intoxicated
  3. The physiological reaction to stopping a substance abruptly
  4. The guilt and loss of control that follow a single lapse and increase risk of full relapse Correct answer.

Explanation

The abstinence violation effect describes the negative cognitive and emotional response, such as guilt and self-blame, after a lapse in people committed to abstinence. This reaction can escalate a single slip into a full relapse.

Question 19Theories, Models, and Principles of Addiction and Recovery

Which of the following best represents the transtheoretical model's assumption about how people move through stages?

  1. Movement can be cyclical with recycling through earlier stages. Correct answer.
  2. Movement is strictly linear and one-directional.
  3. Movement occurs only through professional treatment.
  4. Movement is unrelated to readiness to change.

Explanation

The model describes change as cyclical, with people often recycling through earlier stages after lapses before progressing. Progression is not assumed to be linear or dependent on formal treatment.

Question 20Theories, Models, and Principles of Addiction and Recovery

A counselor uses a decisional balance exercise in which a client lists pros and cons of continuing versus stopping use. This technique is most closely associated with which approach?

  1. Aversion therapy
  2. Electroconvulsive therapy
  3. Motivational interviewing and the transtheoretical model Correct answer.
  4. Psychoanalytic free association

Explanation

Decisional balance is a tool used within motivational interviewing and the transtheoretical model to explore ambivalence by weighing pros and cons. It aims to help clients resolve ambivalence and move toward change.

Question 21Theories, Models, and Principles of Addiction and Recovery

Which statement about the relationship between the disease model and stigma is most accurate?

  1. The disease model has no effect on stigma.
  2. The disease model has been used both to reduce blame by framing addiction as illness and to increase fatalism by implying it is untreatable. Correct answer.
  3. The disease model always eliminates stigma completely.
  4. The disease model is incompatible with any clinical treatment.

Explanation

Framing addiction as a disease can reduce moral blame, but it can also foster fatalism if the condition is perceived as permanent or untreatable. The model's effect on stigma is therefore mixed and depends on how it is communicated.

Question 22Theories, Models, and Principles of Addiction and Recovery

Which concept from social cognitive theory describes a person's belief that they can successfully resist using a substance in a specific high-risk situation?

  1. Abstinence self-efficacy Correct answer.
  2. Locus of control
  3. Learned helplessness
  4. Delay discounting

Explanation

Abstinence self-efficacy is the situation-specific belief in one's ability to resist use, and it strongly predicts coping and relapse outcomes. It is a core construct in social cognitive and relapse prevention models.

Question 23Theories, Models, and Principles of Addiction and Recovery

A treatment program provides clean syringes and naloxone without requiring abstinence. This program is best described as operating from which framework?

  1. Moral model
  2. Harm reduction Correct answer.
  3. Aversion therapy
  4. Disease denial

Explanation

Providing sterile equipment and overdose reversal medication without requiring abstinence are hallmark harm reduction strategies aimed at reducing negative consequences. The approach prioritizes safety and engagement over abstinence as a precondition.

Question 24Theories, Models, and Principles of Addiction and Recovery

Which of the following best distinguishes the psychodynamic perspective on addiction from the behavioral perspective?

  1. Both perspectives focus exclusively on neurotransmitter activity.
  2. Psychodynamic theory emphasizes unconscious conflicts and early relationships, whereas behavioral theory emphasizes observable reinforcement contingencies. Correct answer.
  3. Both perspectives reject the role of early life experience entirely.
  4. Psychodynamic theory emphasizes reinforcement schedules, whereas behavioral theory emphasizes unconscious drives.

Explanation

Psychodynamic theory locates the roots of addiction in unconscious conflict, defense mechanisms, and early relational experience. Behavioral theory instead explains use through observable antecedents, consequences, and learning contingencies.

Question 25Neurobiology and Pharmacology of Substance Use

Which brain reward pathway is most strongly associated with the reinforcing effects of drugs of abuse?

  1. The nigrostriatal pathway from the substantia nigra to the dorsal striatum
  2. The mesolimbic dopamine pathway from the ventral tegmental area to the nucleus accumbens Correct answer.
  3. The tuberoinfundibular pathway from the hypothalamus to the pituitary
  4. The corticospinal tract from the motor cortex to the spinal cord

Explanation

The mesolimbic dopamine projection from the VTA to the nucleus accumbens is the central substrate for drug reinforcement. Most addictive drugs increase dopamine signaling along this pathway. The other pathways serve motor, endocrine, or motor-output functions rather than reward.

Question 26Neurobiology and Pharmacology of Substance Use

Which neurotransmitter is the primary target of benzodiazepines at the receptor level?

  1. Glutamate
  2. GABA Correct answer.
  3. Dopamine
  4. Serotonin

Explanation

Benzodiazepines bind allosterically to GABA-A receptors and enhance inhibitory chloride currents. This potentiation of GABAergic inhibition produces their anxiolytic and sedative effects. Glutamate, dopamine, and serotonin are not the direct binding targets.

Question 27Neurobiology and Pharmacology of Substance Use

A patient abruptly stops heavy alcohol use after years of daily drinking. Which neuroadaptive change best explains the withdrawal seizure risk?

  1. Downregulation of NMDA receptors and enhanced GABA-A inhibition
  2. Loss of mu-opioid receptors in the brainstem
  3. Upregulation of NMDA receptors and reduced GABA-A inhibition Correct answer.
  4. Increased dopamine D2 receptor sensitivity in the striatum

Explanation

Chronic alcohol suppresses NMDA receptors and potentiates GABA-A inhibition. The brain compensates by increasing NMDA receptor numbers and reducing GABAergic tone, so abrupt removal leaves the nervous system hyperexcitable. This hyperexcitability underlies withdrawal seizures.

Question 28Neurobiology and Pharmacology of Substance Use

Which effect distinguishes a full opioid agonist from a partial opioid agonist at the mu receptor?

  1. A full agonist binds only to delta receptors, while a partial agonist binds to mu receptors
  2. A full agonist cannot be reversed by naloxone, while a partial agonist can
  3. A full agonist is always shorter-acting than a partial agonist
  4. A full agonist can produce maximal receptor activation, while a partial agonist produces a ceiling effect Correct answer.

Explanation

Full agonists such as morphine can achieve maximal intrinsic activity at mu receptors. Partial agonists such as buprenorphine produce submaximal activation and show a ceiling effect on respiratory depression. Binding selectivity and reversibility by antagonists are not what defines full versus partial agonism.

Question 29Neurobiology and Pharmacology of Substance Use

Cocaine's reinforcing effect is primarily produced by which mechanism?

  1. Direct release of dopamine from synaptic vesicles
  2. Irreversible inhibition of monoamine oxidase
  3. Competitive antagonism at dopamine D2 receptors
  4. Blockade of dopamine, norepinephrine, and serotonin reuptake transporters Correct answer.

Explanation

Cocaine blocks the reuptake transporters for dopamine, norepinephrine, and serotonin, prolonging monoamine action in the synapse. This transporter blockade, especially for dopamine in the nucleus accumbens, drives reinforcement. It does not act as a receptor antagonist or an MAO inhibitor.

Question 30Neurobiology and Pharmacology of Substance Use

Amphetamine differs from cocaine in that amphetamine also does which of the following?

  1. Acts as a competitive antagonist at nicotinic acetylcholine receptors
  2. Inhibits acetylcholinesterase in the synaptic cleft
  3. Reverses monoamine transporters to promote transmitter efflux and enters vesicles to displace dopamine Correct answer.
  4. Binds directly to GABA-A receptors to enhance inhibition

Explanation

Amphetamine is a substrate for monoamine transporters and reverses their direction, driving transmitter efflux; it also enters vesicles via VMAT to displace dopamine into the cytoplasm. Cocaine only blocks reuptake. GABA, nicotinic, and acetylcholinesterase actions are unrelated to amphetamine.

Question 31Neurobiology and Pharmacology of Substance Use

Nicotine's primary reinforcing action is mediated through which receptor?

  1. The dopamine D1 receptor
  2. The nicotinic acetylcholine receptor, particularly alpha4-beta2 subtypes in the VTA Correct answer.
  3. The mu-opioid receptor
  4. The cannabinoid CB1 receptor

Explanation

Nicotine is an agonist at nicotinic acetylcholine receptors, and alpha4-beta2-containing receptors in the ventral tegmental area are key for its rewarding effects. Activation of these receptors increases dopamine release in the nucleus accumbens. Opioid, cannabinoid, and dopamine receptors are not the direct binding site.

Question 32Neurobiology and Pharmacology of Substance Use

Cannabis produces its psychoactive effects primarily by acting at which receptor?

  1. The cannabinoid CB2 receptor as a full agonist
  2. The NMDA receptor as a positive allosteric modulator
  3. The cannabinoid CB1 receptor as a partial agonist Correct answer.
  4. The serotonin 5-HT2A receptor as an antagonist

Explanation

Delta-9-THC acts as a partial agonist at CB1 receptors, which are abundant in the brain and mediate the psychoactive effects. CB2 receptors are mainly immune-related. Serotonin and NMDA receptors are targets of other drug classes.

Question 33Neurobiology and Pharmacology of Substance Use

Which receptor is the principal target through which LSD and psilocybin produce their psychedelic effects?

  1. The serotonin 5-HT2A receptor Correct answer.
  2. The dopamine D2 receptor
  3. The mu-opioid receptor
  4. The GABA-A receptor

Explanation

Classic psychedelics such as LSD and psilocybin are agonists at serotonin 5-HT2A receptors. Activation of cortical 5-HT2A receptors is considered central to their hallucinogenic effects. Dopamine, GABA, and opioid receptors are not the primary mediators.

Question 34Neurobiology and Pharmacology of Substance Use

A patient on long-term prescribed opioids develops tolerance. Which statement best explains the mechanism?

  1. Opioid receptors mutate to become insensitive to all ligands permanently
  2. The drug is metabolized faster because liver enzymes are destroyed
  3. Repeated receptor activation leads to reduced receptor responsiveness and downstream adaptation Correct answer.
  4. Receptor number is permanently reduced with no possibility of recovery

Explanation

Tolerance arises from adaptive changes such as receptor desensitization, internalization, and downstream signaling adjustments after repeated activation. These changes reduce drug effect at a given dose. They are functional and often reversible, not permanent receptor destruction or mutation.

Question 35Neurobiology and Pharmacology of Substance Use

Which statement best describes the role of the prefrontal cortex in addiction?

  1. It is the primary site of drug metabolism in the brain
  2. It directly produces dopamine for the entire brain
  3. It governs impulse control and decision-making, and its dysfunction contributes to compulsive drug use Correct answer.
  4. It controls respiration and is the main site of opioid-induced death

Explanation

The prefrontal cortex supports executive functions such as impulse control, planning, and evaluating consequences. Impaired prefrontal regulation is thought to contribute to loss of control over drug use. It does not metabolize drugs, produce brain-wide dopamine, or control respiration.

Question 36Neurobiology and Pharmacology of Substance Use

The brainstem's role in opioid overdose mortality is best described as which of the following?

  1. It contains respiratory centers whose mu-opioid-mediated suppression causes fatal hypoventilation Correct answer.
  2. It metabolizes opioids into toxic byproducts
  3. It generates the craving that leads to overdose
  4. It stores drugs and slowly releases them into the blood

Explanation

Mu-opioid receptors in brainstem respiratory centers blunt the response to rising carbon dioxide. This produces hypoventilation, which is the primary cause of death in opioid overdose. The brainstem is not a drug reservoir, a craving center, or a metabolic organ.

Question 37Neurobiology and Pharmacology of Substance Use

Which mechanism best explains why disulfiram discourages alcohol consumption?

  1. It inhibits aldehyde dehydrogenase, causing acetaldehyde accumulation and an aversive reaction Correct answer.
  2. It blocks dopamine D2 receptors to reduce craving
  3. It antagonizes mu-opioid receptors to block alcohol reward
  4. It enhances GABA-A receptor activity to prevent withdrawal

Explanation

Disulfiram inhibits aldehyde dehydrogenase, so acetaldehyde builds up when alcohol is consumed. The resulting flushing, nausea, and tachycardia create an aversive consequence. It does not act on dopamine, GABA, or opioid receptors.

Question 38Neurobiology and Pharmacology of Substance Use

Naltrexone reduces alcohol relapse most plausibly through which action?

  1. Inhibiting aldehyde dehydrogenase to cause aversive reactions
  2. Blocking mu-opioid receptors that modulate alcohol-induced reward Correct answer.
  3. Blocking dopamine reuptake transporters
  4. Enhancing GABA-A inhibition during withdrawal

Explanation

Alcohol reward partly involves endogenous opioid signaling, and naltrexone blocks mu-opioid receptors to blunt that reward. This reduces the reinforcing pleasure of drinking. It is not an aldehyde dehydrogenase inhibitor, a GABA enhancer, or a reuptake blocker.

Question 39Neurobiology and Pharmacology of Substance Use

Which medication is a partial mu-opioid agonist used for opioid use disorder that also reduces overdose risk through a ceiling effect?

  1. Clonidine
  2. Naloxone
  3. Buprenorphine Correct answer.
  4. Methadone

Explanation

Buprenorphine is a partial mu agonist with high affinity and a ceiling on respiratory depression, making it useful for maintenance treatment. Methadone is a full agonist. Naloxone is an antagonist and clonidine is an alpha-2 agonist used for withdrawal symptoms.

Question 40Neurobiology and Pharmacology of Substance Use

Which statement about the endogenous opioid system is most accurate?

  1. Endogenous opioids are excitatory amino acids acting at NMDA receptors
  2. Endogenous opioids act only at dopamine receptors
  3. Endorphins and enkephalins act at mu, delta, and kappa receptors to modulate pain and reward Correct answer.
  4. Endogenous opioids are stored in vesicles and released only during sleep

Explanation

Endogenous opioid peptides such as endorphins, enkephalins, and dynorphins act at mu, delta, and kappa receptors. They modulate pain perception, reward, and stress responses. They are not dopamine, not excitatory amino acids, and are released in many behavioral states.

Question 41Neurobiology and Pharmacology of Substance Use

A researcher finds that a drug increases dopamine in the nucleus accumbens but the animal does not self-administer it. Which conclusion is most reasonable?

  1. Self-administration is unrelated to any neurochemistry
  2. Dopamine elevation alone is not sufficient for reinforcement; other factors contribute Correct answer.
  3. The animal has no dopamine receptors
  4. The drug must be a dopamine antagonist

Explanation

Dopamine in the accumbens is important for reinforcement but not sufficient by itself. Factors such as receptor subtype, timing, and other transmitter systems influence whether a drug is self-administered. The finding does not imply antagonism or absent receptors.

Question 42Neurobiology and Pharmacology of Substance Use

Which change in glutamatergic signaling is implicated in the development of drug craving and relapse?

  1. Permanent closure of voltage-gated sodium channels
  2. Complete loss of all glutamate receptors in the cerebellum
  3. Selective destruction of serotonergic neurons in the raphe
  4. Altered AMPA and NMDA receptor expression and synaptic strength in the nucleus accumbens and prefrontal cortex Correct answer.

Explanation

Repeated drug exposure produces glutamatergic plasticity, including changes in AMPA and NMDA receptor expression and synaptic strength in reward and prefrontal circuits. This plasticity is linked to cue-induced craving and relapse. It is not a global receptor loss, raphe destruction, or channel closure.

Question 43Neurobiology and Pharmacology of Substance Use

Which statement best captures the concept of incentive sensitization in addiction?

  1. Repeated drug exposure permanently eliminates all pleasure from natural rewards
  2. The drug becomes less wanted while remaining equally liked
  3. Repeated drug exposure makes reward circuits hypersensitive to drug-associated cues, driving wanting Correct answer.
  4. Tolerance to the drug always prevents any further use

Explanation

Incentive sensitization theory holds that repeated drug exposure sensitizes mesolimbic systems so that drug cues trigger amplified wanting. This wanting can persist even as the drug's euphoric effects decline. It does not mean total loss of natural reward or simple tolerance preventing use.

Question 44Neurobiology and Pharmacology of Substance Use

Which statement about the blood-brain barrier and drugs of abuse is most accurate?

  1. Lipophilic drugs cross more readily, while highly polar drugs cross poorly unless actively transported Correct answer.
  2. The barrier actively pumps all drugs into the brain
  3. All drugs cross equally because the barrier is freely permeable to small molecules
  4. Only drugs that bind plasma proteins can enter the brain

Explanation

The blood-brain barrier restricts polar and large molecules while allowing lipophilic drugs to diffuse across. Some polar compounds require specific transporters. The barrier is not freely permeable, does not pump all drugs inward, and protein binding generally limits rather than enables entry.

Question 45Neurobiology and Pharmacology of Substance Use

Which neuroadaptation most directly underlies tolerance to the sedative effects of chronic benzodiazepine use?

  1. Increased expression of NMDA receptors only
  2. Permanent loss of all GABA neurons
  3. Downregulation and uncoupling of GABA-A receptors Correct answer.
  4. Complete saturation of hepatic metabolism

Explanation

Chronic benzodiazepine exposure leads to reduced GABA-A receptor function through downregulation and uncoupling. This reduces the inhibitory response at a given dose, producing tolerance. It is not neuronal loss, isolated NMDA changes, or metabolic saturation.

Question 46Neurobiology and Pharmacology of Substance Use

Which mechanism best explains the reinforcing effects of alcohol at the synaptic level?

  1. Direct agonism at mu-opioid receptors
  2. Selective blockade of dopamine D2 receptors
  3. Inhibition of monoamine oxidase type B
  4. Enhanced GABA-A inhibition combined with reduced NMDA receptor activity, plus dopamine release in reward circuits Correct answer.

Explanation

Alcohol potentiates GABA-A receptor function and inhibits NMDA receptors, producing sedation and disinhibition. It also indirectly increases dopamine release in reward circuits, contributing to reinforcement. It is not a D2 antagonist, mu agonist, or MAO-B inhibitor.

Question 47Neurobiology and Pharmacology of Substance Use

Which brain region is most associated with conditioned responses to drug-associated cues?

  1. The amygdala Correct answer.
  2. The cerebellum
  3. The primary visual cortex
  4. The medulla oblongata

Explanation

The amygdala is central to emotional learning and conditioned associations between cues and drug reward. Cue-induced responses can trigger craving and relapse. The cerebellum, medulla, and primary visual cortex are not the principal sites for this associative learning.

Question 48Neurobiology and Pharmacology of Substance Use

A drug that blocks dopamine D2 receptors in the nucleus accumbens would most likely have which effect on stimulant reward?

  1. It would intensify the rewarding effects of the stimulant
  2. It would attenuate the rewarding effects of the stimulant Correct answer.
  3. It would convert the stimulant into an opioid agonist
  4. It would have no effect on stimulant reward

Explanation

Stimulant reward depends substantially on increased dopamine action at D2 receptors in the accumbens. Blocking those receptors reduces the reward signal. It would not intensify reward or change the drug's receptor class.

Question 49Screening, Assessment, and Diagnosis

A client reports eating large amounts of food in secret and then vomiting to control weight at least twice weekly for the past four months. Which diagnosis best fits this presentation?

  1. Bulimia nervosa Correct answer.
  2. Avoidant/restrictive food intake disorder
  3. Binge-eating disorder
  4. Anorexia nervosa, binge-purge type

Explanation

Bulimia nervosa is characterized by recurrent binge eating with compensatory behaviors such as self-induced vomiting, occurring at least weekly for three months, in the absence of significantly low body weight. Binge-purge anorexia would require a markedly low body weight, which is not described.

Question 50Screening, Assessment, and Diagnosis

On the CAGE screening tool, a client answers yes to cutting down and to feeling annoyed by criticism of drinking, and no to the remaining items. What does this score indicate?

  1. The screen is inconclusive and should be repeated in one year
  2. The screen is invalid until all four items are endorsed
  3. The screen is positive and warrants further assessment Correct answer.
  4. The screen is negative because fewer than three items were endorsed

Explanation

The CAGE is scored so that endorsement of two or more of the four items constitutes a positive screen. A positive result signals the need for a fuller alcohol assessment rather than a diagnosis.