Substance Use Disorders — MCQs

Substance Use Disorders Indian Medical PG Practice Questions and MCQs

Question 231: Which of the following drugs is not used in opioid dependence?

A. Disulfiram (Correct Answer)
B. Clonidine
C. Lorazepam
D. Naltrexone

Explanation: **Explanation:** The management of opioid dependence involves two phases: detoxification (managing withdrawal) and maintenance (preventing relapse). **Why Disulfiram is the Correct Answer:** **Disulfiram** is an aldehyde dehydrogenase inhibitor used exclusively in the treatment of **Alcohol Dependence**. It creates an aversive reaction (Disulfiram-ethanol reaction) by causing acetaldehyde buildup if alcohol is consumed. It has no pharmacological role in the opioid pathway or the management of opioid withdrawal/dependence. **Analysis of Other Options:** * **Clonidine:** An alpha-2 adrenergic agonist used to manage the **autonomic symptoms of opioid withdrawal** (e.g., hypertension, tachycardia, sweating, and lacrimation). It reduces the sympathetic overactivity triggered by the locus coeruleus during detox. * **Lorazepam:** A benzodiazepine used as an adjuvant during opioid withdrawal to manage **insomnia, anxiety, and muscle cramps**. While not a primary treatment for dependence, it is frequently used in the acute detoxification phase. * **Naltrexone:** An **opioid antagonist** used for maintenance therapy. It blocks the "high" of opioids and is used in highly motivated patients to prevent relapse after complete detoxification. **NEET-PG High-Yield Pearls:** * **Gold Standard for Opioid Detoxification:** Methadone or Buprenorphine. * **Drug of Choice for Opioid Overdose:** Naloxone (short-acting antagonist). * **Maintenance Therapy:** Methadone (full agonist) is the most common; Buprenorphine (partial agonist) is used for "office-based" treatment. * **Clonidine** is non-addictive, making it a preferred non-opioid option for withdrawal management in outpatient settings.

Question 232: All of the following are true about alcohol abuse except?

A. Alcoholic hallucinosis is seen after 12-24 hours of alcohol withdrawal.
B. MCV is decreased in chronic alcoholics. (Correct Answer)
C. Widmark formula is used to calculate blood alcohol concentration.
D. CAGE questionnaire is used as a screening test for alcohol abuse.

Explanation: ### Explanation **Correct Answer: B. MCV is decreased in chronic alcoholics.** **1. Why Option B is the Correct Answer (The False Statement):** In chronic alcoholics, the **Mean Corpuscular Volume (MCV) is increased (Macrocytosis)**, not decreased. This occurs due to two primary reasons: * **Direct Toxicity:** Alcohol has a direct toxic effect on the bone marrow, interfering with erythrocyte maturation. * **Nutritional Deficiency:** Chronic alcoholics often have a secondary deficiency of **Folic acid** (and occasionally Vitamin B12) due to poor diet and impaired absorption, leading to megaloblastic changes. * *Clinical Note:* An elevated MCV is a sensitive biological marker for long-term heavy drinking. **2. Analysis of Other Options:** * **Option A (True):** **Alcoholic hallucinosis** typically occurs within 12–24 hours after the last drink. It is characterized by vivid auditory hallucinations (often accusatory) in a state of clear consciousness, distinguishing it from Delirium Tremens. * **Option C (True):** The **Widmark Formula** ($A = c \times p \times r$) is the standard forensic calculation used to estimate Blood Alcohol Concentration (BAC) based on the amount of alcohol consumed, body weight, and the gender-specific distribution ratio. * **Option D (True):** The **CAGE Questionnaire** is a high-yield screening tool consisting of four questions: **C**ut down, **A**nnoyed, **G**uilty, and **E**ye-opener. A score of $\geq 2$ is clinically significant. **3. High-Yield Clinical Pearls for NEET-PG:** * **Most sensitive marker** for chronic alcohol use: **GGT** (Gamma-Glutamyl Transferase). * **Most specific marker** for recent heavy drinking: **CDT** (Carbohydrate Deficient Transferrin). * **Wernicke’s Encephalopathy Triad:** Confusion, Ataxia, and Ophthalmoplegia (due to Thiamine/B1 deficiency). * **Delirium Tremens:** Occurs 48–72 hours after withdrawal; characterized by autonomic hyperactivity and clouded consciousness.

Question 233: A patient presents with conjunctival congestion, increased appetite, dry mouth, tachycardia, and synesthesia. Which substance is most likely responsible for these effects?

A. Cannabis (Correct Answer)
B. Caffeine
C. Cocaine
D. Codeine

Explanation: ### Explanation The clinical presentation described is classic for **Cannabis (Marijuana)** intoxication. **1. Why Cannabis is correct:** Cannabis acts on CB1 and CB2 receptors. The hallmark signs include: * **Conjunctival Congestion:** Dilation of conjunctival blood vessels (red eyes) is a highly specific physical sign. * **Increased Appetite:** Often referred to as "the munchies." * **Dry Mouth (Xerostomia):** Due to the inhibition of parasympathetic signaling to salivary glands. * **Tachycardia:** A common cardiovascular response to THC. * **Synesthesia:** A perceptual phenomenon where senses "blend" (e.g., "hearing colors" or "seeing sounds"). While common in LSD, it is a high-yield feature of cannabis intoxication in psychiatric exams. **2. Why the other options are incorrect:** * **Caffeine:** Causes tachycardia and anxiety, but leads to insomnia and decreased appetite, not conjunctival congestion or synesthesia. * **Cocaine:** A potent stimulant causing pupillary **dilation (mydriasis)**, hypertension, and agitation. It typically suppresses appetite. * **Codeine:** An opioid that causes pupillary **constriction (miosis)**, respiratory depression, and constipation. It does not cause conjunctival congestion or synesthesia. **3. High-Yield Clinical Pearls for NEET-PG:** * **Amotivational Syndrome:** A chronic effect of cannabis use characterized by apathy, lack of energy, and social withdrawal. * **Flashbacks:** Spontaneous recurrences of sensory distortions (more common with LSD, but can occur with cannabis). * **Therapeutic Use:** Cannabinoids (e.g., Dronabinol) are used for chemotherapy-induced nausea and appetite stimulation in AIDS-related wasting. * **Psychosis:** Cannabis is a known risk factor for precipitating schizophrenia in genetically predisposed individuals.

Question 234: An alcoholic patient feels like insects are running over his skin. This is known as:

A. Formication (Correct Answer)
B. Delusion
C. Dementia
D. Delirium

Explanation: **Explanation:** The correct answer is **Formication**. **1. Why Formication is correct:** Formication is a specific type of **tactile hallucination** where a patient perceives a sensation of small insects crawling on or under the skin. In the context of alcohol, it is a classic symptom of **Alcohol Withdrawal**, particularly during Delirium Tremens. It is also frequently associated with stimulant use, such as cocaine ("Cocaine bugs") or amphetamines. The underlying mechanism involves spontaneous firing of sensory neurons or central nervous system excitability during withdrawal states. **2. Why the other options are incorrect:** * **Delusion:** This is a disorder of **thought content**, defined as a fixed, false belief that is out of keeping with the patient’s social and cultural background. It is not a sensory perception. * **Dementia:** This is a chronic, progressive disorder of **cognition** (memory, executive function) without impairment of consciousness. While alcohol can cause dementia (e.g., Wernicke-Korsakoff syndrome), it does not specifically describe a crawling skin sensation. * **Delirium:** This is an acute state of **altered consciousness** and global cognitive impairment. While formication can occur *during* delirium (specifically Delirium Tremens), the term "delirium" refers to the overall clinical syndrome, not the specific sensory symptom described. **Clinical Pearls for NEET-PG:** * **Tactile Hallucinations:** Most commonly seen in organic states (substance withdrawal/intoxication) rather than functional psychoses like Schizophrenia (where auditory hallucinations dominate). * **Ekbom Syndrome:** Also known as Delusional Parasitosis, where the patient has a fixed false belief of being infested with parasites, often leading to "matchbox sign" (bringing skin debris in a container to show the doctor). * **Alcohol Withdrawal Timeline:** Formication and visual hallucinations typically occur 12–48 hours after the last drink.

Question 235: Which of the following is NOT a characteristic feature of Korsakoff's Psychosis?

A. Memory disturbances
B. Suicidal tendencies (Correct Answer)
C. Loss of recent memory
D. Psychosis

Explanation: **Explanation:** Korsakoff’s Psychosis (or Korsakoff’s Syndrome) is a chronic neuropsychiatric disorder caused by a severe deficiency of **Thiamine (Vitamin B1)**, most commonly seen in chronic alcoholics. It often follows an untreated episode of Wernicke’s Encephalopathy. **Why "Suicidal tendencies" is the correct answer:** Suicidal tendencies are not a characteristic or diagnostic feature of Korsakoff’s Psychosis. While patients with alcohol use disorder may have comorbid depression, the primary pathology of Korsakoff’s is cognitive and amnestic, not mood-related. Patients often exhibit **apathy** or a lack of insight, rather than active suicidal ideation. **Analysis of other options:** * **Memory disturbances & Loss of recent memory:** These are the hallmarks of the syndrome. Specifically, patients suffer from **anterograde amnesia** (inability to form new memories) and some retrograde amnesia. * **Psychosis:** In this context, "psychosis" refers to the patient’s lack of insight and the presence of **confabulation** (filling memory gaps with fabricated stories). The patient is not "lying" intentionally but is out of touch with reality regarding their memory. **High-Yield Clinical Pearls for NEET-PG:** * **The Triad of Wernicke’s Encephalopathy:** Confusion, Ataxia, and Ophthalmoplegia (GOA: Gaze palsy, Ophthalmoplegia, Ataxia). * **Korsakoff’s Features:** Anterograde amnesia, Retrograde amnesia, and **Confabulation**. * **Pathology:** Characterized by lesions in the **mammillary bodies** and the dorsomedial nucleus of the thalamus. * **Treatment:** High-dose intravenous Thiamine. Always give Thiamine *before* Glucose to avoid precipitating Wernicke’s in a malnourished patient.

Question 236: "Bad-trip" is associated with which of the following substances?

A. Bhang
B. Ganja
C. Cocaine
D. LSD (Correct Answer)

Explanation: **Explanation:** The term **"Bad-trip"** refers to a **Panic Reaction** or an acute adverse psychological reaction characterized by intense anxiety, terrifying hallucinations, loss of control, and a fear of impending doom. This phenomenon is most classically and frequently associated with **LSD (Lysergic Acid Diethylamide)**, a potent hallucinogen. **Why LSD is the correct answer:** LSD acts primarily as a partial agonist at **5-HT2A receptors**. The "bad trip" occurs when the psychedelic experience becomes overwhelming. Patients may experience "horrific" visual hallucinations (e.g., seeing themselves decomposing) or "synesthesia" (hearing colors/seeing sounds). Management typically involves a "talk-down" approach in a quiet room or the use of benzodiazepines. **Analysis of Incorrect Options:** * **Bhang & Ganja (Cannabis):** While high doses of cannabis can cause "Cannabis Psychosis" or acute panic, the specific nomenclature "bad-trip" is the hallmark of hallucinogens like LSD. Cannabis is more commonly associated with "Amotivational Syndrome" and "Run-Amok." * **Cocaine:** As a potent sympathomimetic stimulant, cocaine toxicity presents with tachycardia, hypertension, and "Cocaine Bugs" (Formication/Magnan’s sign). It does not typically cause the classic hallucinogenic "bad trip." **High-Yield Clinical Pearls for NEET-PG:** * **Flashbacks (Hallucinogen Persisting Perception Disorder):** Recurrence of the LSD experience weeks or months after the last dose. * **LSD Source:** Derived from the fungus *Claviceps purpurea* (Ergot). * **Pupillary Sign:** LSD causes marked **Mydriasis** (dilated pupils), whereas Opioids cause Miosis (pinpoint pupils). * **Tolerance:** LSD shows rapid tolerance but **no physical dependence** or withdrawal symptoms.

Question 237: Amotivational syndrome is seen with which substance?

A. Heroin
B. Cannabis (Correct Answer)
C. Cocaine
D. Clonidine

Explanation: **Explanation:** **Amotivational Syndrome** is a controversial but clinically recognized chronic psychiatric condition characterized by a loss of ambition, apathy, diminished ability to carry out complex plans, and a lack of interest in future goals. **1. Why Cannabis is correct:** Amotivational syndrome is classically associated with **chronic, heavy use of Cannabis**. The underlying medical concept involves the downregulation of dopamine receptors in the reward circuitry and frontal lobe dysfunction. Patients typically present with "flattened affect," poor personal hygiene, social withdrawal, and a marked decline in academic or occupational performance, even when not acutely intoxicated. **2. Why other options are incorrect:** * **Heroin (Opioids):** Chronic use leads to physical dependence, tolerance, and withdrawal symptoms (lacrimation, rhinorrhea, yawning). While it causes sedation, it does not typically manifest as the specific "amotivational" cluster. * **Cocaine (Stimulants):** Cocaine use is associated with euphoria, increased energy, and hypervigilance. Chronic use or withdrawal leads to "crashing" (depression and hypersomnia), but not the distinct amotivational syndrome. * **Clonidine:** This is an alpha-2 agonist used to manage opioid withdrawal symptoms (autonomic hyperactivity). It is not a drug of abuse associated with this syndrome. **Clinical Pearls for NEET-PG:** * **Cannabis and Psychosis:** Cannabis is a known risk factor for precipitating **Schizophrenia** in genetically predisposed individuals. * **Flashbacks:** Also known as Hallucinogen Persisting Perception Disorder (HPPD), these are common with LSD but can also occur with Cannabis. * **Run Amok:** A culture-bound syndrome traditionally associated with cannabis use (though now considered more broadly) involving a sudden outburst of violent or homicidal behavior. * **Active Ingredient:** Delta-9-tetrahydrocannabinol (THC).

Question 238: A patient presents with the sensation of bugs crawling all over his body. This symptom may be an effect of which of the following substances?

A. Cocaine (Correct Answer)
B. Alcohol
C. Cannabis
D. Benzodiazepines

Explanation: **Explanation:** The correct answer is **Cocaine**. The sensation of bugs crawling on or under the skin is a specific type of tactile hallucination known as **Formication**. When specifically associated with chronic cocaine use, it is famously referred to as **"Cocaine Bugs"** or **Magnan’s sign**. **Why Cocaine is Correct:** Cocaine is a potent stimulant that increases synaptic dopamine levels. Chronic use or acute toxicity can lead to "Cocaine Psychosis," characterized by paranoid delusions and tactile hallucinations. Patients may scratch or pick at their skin to "remove" these non-existent insects, leading to characteristic skin excoriations known as "pick marks." **Why Other Options are Incorrect:** * **Alcohol:** While alcohol withdrawal can cause hallucinations, they are typically visual (e.g., seeing small animals) or auditory. Formication is more classically associated with stimulants. * **Cannabis:** Cannabis intoxication typically presents with conjunctival injection, increased appetite, and distorted sensory perception (time slowing down), but rarely tactile hallucinations. * **Benzodiazepines:** These are CNS depressants. Withdrawal can cause tremors, seizures, and delirium, but formication is not a hallmark feature. **High-Yield Clinical Pearls for NEET-PG:** 1. **Magnan’s Sign:** The specific term for the tactile hallucination of insects crawling under the skin in cocaine users. 2. **Differential Diagnosis:** Formication can also be seen in **Amphetamine** use and **Alcohol withdrawal (Delirium Tremens)**, but Cocaine is the most classic association in exams. 3. **Mechanism:** Cocaine blocks the reuptake of Dopamine, Norepinephrine, and Serotonin. 4. **Physical Sign:** Look for perforated nasal septum and dilated pupils (mydriasis) in cocaine-related clinical vignettes.

Question 239: Disulfiram is used to treat which of the following conditions?

A. Opioid dependence
B. Alcohol dependence (Correct Answer)
C. Cocaine dependence
D. Amphetamine dependence

Explanation: **Explanation:** **Disulfiram** is a classic pharmacological intervention used as an **aversion therapy** for **Alcohol Dependence**. **Mechanism of Action:** Under normal conditions, alcohol is metabolized into acetaldehyde by alcohol dehydrogenase, which is then converted into acetic acid by the enzyme **Aldehyde Dehydrogenase (ALDH)**. Disulfiram irreversibly inhibits ALDH. When a patient consumes alcohol while on Disulfiram, acetaldehyde accumulates in the blood, leading to the **Disulfiram-Ethanol Reaction (DER)**. This reaction is characterized by flushing, tachycardia, nausea, vomiting, headache, and hypotension, serving as a powerful psychological deterrent against drinking. **Analysis of Incorrect Options:** * **Opioid Dependence:** Managed with agonists (Methadone), partial agonists (Buprenorphine), or antagonists (Naltrexone). Disulfiram has no role in opioid receptor modulation. * **Cocaine & Amphetamine Dependence:** These stimulant use disorders are primarily managed through behavioral therapies (Contingency Management). While some studies have explored Disulfiram for cocaine (due to its effect on dopamine beta-hydroxylase), it is not the standard or FDA-approved treatment. **High-Yield Clinical Pearls for NEET-PG:** * **Timing:** Disulfiram should never be administered until the patient has abstained from alcohol for at least **12 hours**. * **Duration:** The effects can last up to **1–2 weeks** after the last dose because the body must synthesize new ALDH enzymes. * **Contraindications:** Severe cardiac disease, psychosis, and pregnancy. * **Acamprosate vs. Naltrexone:** Remember that while Disulfiram is for aversion, **Naltrexone** reduces cravings/reward, and **Acamprosate** is best for maintaining abstinence by stabilizing glutamate/GABA neurochemistry.

Question 240: Which substance, if used for a prolonged period, is associated with memory loss?

A. Marijuana
B. Alcohol (Correct Answer)
C. Cocaine
D. LSD

Explanation: **Explanation:** **Alcohol** is the correct answer because its chronic use is classically associated with severe memory impairment through both direct neurotoxicity and nutritional deficiency. The most high-yield mechanism is **Thiamine (Vitamin B1) deficiency**, which leads to **Wernicke-Korsakoff Syndrome**. While Wernicke’s is an acute neurological emergency, **Korsakoff Psychosis** is the chronic phase characterized by profound **anterograde amnesia** (inability to form new memories) and **confabulation** (filling memory gaps with fabricated stories). **Analysis of Incorrect Options:** * **Marijuana:** While acute intoxication causes transient short-term memory impairment and "amotivational syndrome" with chronic use, it does not typically cause the profound, permanent memory loss seen with alcohol. * **Cocaine:** As a stimulant, its chronic use is more closely linked to mood disturbances, paranoia, and cardiovascular complications rather than primary memory loss. * **LSD:** A hallucinogen that primarily causes perceptual distortions (hallucinations) and "flashbacks" (Hallucinogen Persisting Perception Disorder). It is not associated with organic memory deficits. **Clinical Pearls for NEET-PG:** * **Korsakoff’s Triad:** Amnesia, Confabulation, and Lack of Insight. * **Wernicke’s Triad:** Ataxia, Global Confusion, and Ophthalmoplegia (6th nerve palsy). * **Pathology:** Look for **Mammillary body atrophy** on MRI in chronic alcoholics with memory loss. * **Management:** Always administer Thiamine *before* Glucose in suspected cases to prevent precipitating Wernicke’s encephalopathy.

Practice by Chapter

Neurobiology of Addiction

Practice Questions

Alcohol Use Disorder

Practice Questions

Opioid Use Disorder

Practice Questions

Cannabis Use Disorder

Practice Questions

Stimulant Use Disorders

Practice Questions

Sedative, Hypnotic, and Anxiolytic Use Disorders

Practice Questions

Tobacco Use Disorder

Practice Questions

Hallucinogen-Related Disorders

Practice Questions

Substance Withdrawal Syndromes

Practice Questions

Pharmacotherapy for Substance Use Disorders

Practice Questions

Psychosocial Interventions

Practice Questions

Dual Diagnosis Management

Practice Questions

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