Substance Use Disorders Practice Questions

Q: Nicotine acts as an agonist for receptors of a particular neurotransmitter. The worsening of cognitive symptoms in persons with mild cognitive impairments who stop smoking is due to the effect on this neurotransmitter.

Acetylcholine. **Explanation:** **1. Why Acetylcholine is Correct:** Nicotine is a potent agonist of **Nicotinic Acetylcholine Receptors (nAChRs)**, which are widely distributed in the central nervous system. These receptors play a critical role in cognitive functions such as attention, learning, and memory. In patients with mild cognitive impairment (MCI) or early Alzheimer’s disease, there is a known deficit in cholinergic transmission. Chronic smoking provides exogenous stimulation of these receptors; therefore, sudden cessation leads to a "cholinergic void," resulting in the acute worsening of cognitive symptoms and attention deficits. **2. Why Other Options are Incorrect:** * **B. Dopamine:** While nicotine causes the release of dopamine in the *nucleus accumbens* (mediating its addictive and rewarding properties), the specific link to cognitive decline upon withdrawal is primarily mediated by the cholinergic system, not the dopaminergic reward pathway. * **C. Neuropeptide Y:** This is involved in appetite regulation and anxiety but is not the primary receptor target for nicotine nor the mediator of its cognitive effects. * **D. Nitric Oxide:** This is a retrograde neurotransmitter involved in long-term potentiation, but nicotine does not act as a direct agonist for nitric oxide receptors. **3. Clinical Pearls for NEET-PG:** * **Receptor Subtype:** The **α4β2** nicotinic receptor subtype is the primary mediator of nicotine dependence. * **Therapeutic Link:** The cognitive-enhancing effect of nicotine is the reason why **Cholinesterase Inhibitors** (like Donepezil) are the mainstay of treatment for Alzheimer’s disease. * **Smoking & Schizophrenia:** Up to 80-90% of patients with Schizophrenia smoke; this is often viewed as "self-medication" to improve cognitive deficits and sensory gating via nAChR stimulation. * **Withdrawal:** Nicotine withdrawal peaks within 24–48 hours and typically lasts 2–4 weeks.

Q: Which is the most commonly abused opioid?

Diacetylmorphine. **Explanation:** **Diacetylmorphine (Heroin)** is the most commonly abused opioid globally and in India. The primary reason for its high abuse potential is its **high lipid solubility**. When injected or inhaled, it crosses the blood-brain barrier much faster than morphine, leading to an intense, rapid "rush" or euphoria. In the brain, it is rapidly deacetylated into morphine, which then acts on the mu-opioid receptors. Its high potency, rapid onset of action, and widespread illicit availability make it the leading substance in opioid use disorders. **Analysis of Incorrect Options:** * **Morphine (Option A):** While it is the gold standard for pain management, it is less lipid-soluble than heroin, resulting in a slower onset of action in the CNS. It is more commonly associated with medical therapeutic use than street abuse. * **Codeine (Option B):** Often found in cough syrups, it is a weaker opioid. While "purple drank" or syrup abuse exists, the scale of addiction does not match that of heroin. * **Fentanyl (Option D):** It is significantly more potent than heroin (50–100 times more than morphine). While it is the leading cause of overdose deaths in North America, globally and statistically in the Indian context, heroin remains the more commonly abused substance. **NEET-PG High-Yield Pearls:** * **Triad of Opioid Poisoning:** Miosis (pinpoint pupils), Respiratory depression, and Altered sensorium (Coma). * **Exception to Miosis:** Pethidine (Meperidine) poisoning causes **mydriasis** due to its atropine-like action. * **Treatment of Choice:** **Naloxone** (IV) is the antagonist for acute overdose; **Methadone** or **Buprenorphine** are used for substitution therapy in long-term management. * **Withdrawal Symptoms:** Characterized by "flu-like" symptoms: lacrimation, rhinorrhea, yawning, piloerection (gooseflesh), and dilated pupils.

Q: Korsakoff's psychosis is diagnosed by which of the following findings?

Impairment of long-term memory. **Explanation:** Korsakoff’s Psychosis (or Korsakoff Syndrome) is a chronic neuropsychiatric condition resulting from a deficiency of **Thiamine (Vitamin B1)**, most commonly seen in chronic alcoholics. It often follows an untreated or inadequately treated episode of Wernicke’s Encephalopathy. **Why Option C is Correct:** The hallmark of Korsakoff’s psychosis is a profound **anterograde and retrograde amnesia**. While short-term memory (immediate recall) may be preserved, there is a significant **impairment of long-term memory** (the ability to form new memories and retrieve old ones). A classic clinical feature associated with this memory deficit is **confabulation**, where the patient fills memory gaps with fabricated or misinterpreted stories. **Why Other Options are Incorrect:** * **A. Peripheral neuropathy:** While common in chronic alcoholics due to nutritional deficiencies, it is not a diagnostic criterion for Korsakoff’s psychosis. * **B. Visual hallucinations:** These are characteristic of **Delirium Tremens** or Alcoholic Hallucinosis, not Korsakoff’s. * **D. Seizures:** Rum fits (alcohol withdrawal seizures) occur during the withdrawal phase, typically 12–48 hours after the last drink, and are not part of the Korsakoff triad/tetrad. **High-Yield Clinical Pearls for NEET-PG:** * **Wernicke’s Encephalopathy Triad:** Confusion, Ataxia, and Ophthalmoplegia (reversible). * **Korsakoff’s Psychosis:** Amnesia and Confabulation (often irreversible). * **Pathology:** Characterized by lesions in the **mammillary bodies** and the dorsomedial nucleus of the thalamus. * **Management:** Always administer Thiamine **before** Glucose in a suspected alcoholic to prevent precipitating Wernicke’s.

Q: Which of the following is NOT a symptom of opioid withdrawal?

Polyuria. **Explanation:** Opioid withdrawal is characterized by a state of **autonomic hyperactivity** and "everything coming out" (increased secretions). The correct answer is **Polyuria**, as it is not a feature of opioid withdrawal; instead, patients often experience gastrointestinal symptoms like diarrhea. **Why Polyuria is incorrect:** Opioid withdrawal typically involves symptoms of sympathetic overactivity and fluid loss through other channels (sweating, rhinorrhea, diarrhea), but polyuria is not a recognized clinical feature. In fact, opioids themselves can cause urinary retention, and withdrawal usually returns bladder function to baseline rather than causing excessive urination. **Analysis of other options:** * **Yawning:** This is one of the earliest and most characteristic signs of opioid withdrawal, often accompanied by lacrimation and rhinorrhea. * **Fever:** Withdrawal causes a disruption in thermoregulation, leading to low-grade fever, chills, and piloerection ("cold turkey"). * **Insomnia:** Central nervous system irritability leads to significant restlessness, anxiety, and insomnia. **High-Yield Clinical Pearls for NEET-PG:** * **The "Wet" Withdrawal:** Remember the mnemonic for opioid withdrawal: **"Everything is leaking"** (Rhinorrhea, Lacrimation, Diarrhea, Diaphoresis). * **Pupillary Signs:** Opioid **Intoxication** causes "Pinpoint pupils" (Miosis), whereas Opioid **Withdrawal** causes Mydriasis (Dilatation). * **Severity:** While extremely uncomfortable (resembling a severe flu), opioid withdrawal is generally **not life-threatening**, unlike alcohol or benzodiazepine withdrawal. * **Treatment:** The drug of choice for managing withdrawal symptoms is **Clonidine** (alpha-2 agonist) or opioid substitutes like **Methadone** and **Buprenorphine**.

Q: A 40-year-old patient, who has been consuming cannabis regularly for the past 20 years, presents with withdrawal symptoms. What is the most frequently observed withdrawal symptom?

Irritability. ### Explanation **Correct Answer: C. Irritability** Cannabis Withdrawal Syndrome (CWS) is a recognized clinical entity in the DSM-5. It typically occurs in long-term, heavy users within 24–72 hours of cessation. The underlying pathophysiology involves the downregulation of **CB1 receptors** in the brain; when cannabis use stops, there is a rebound increase in CNS excitability. **Irritability** (along with anger and aggression) is the **most common and earliest** symptom of cannabis withdrawal. Other frequent symptoms include anxiety, sleep disturbances (insomnia/vivid dreams), decreased appetite, and restlessness. **Analysis of Incorrect Options:** * **A. Yawning:** This is a classic sign of **Opioid withdrawal**, not cannabis. It is often accompanied by lacrimation, rhinorrhea, and piloerection. * **B. Seizures:** These are characteristic of **Alcohol** or **Benzodiazepine/Sedative-Hypnotic** withdrawal. Cannabis withdrawal does not typically lower the seizure threshold. * **D. Tremors:** While mild tremors can occur in cannabis withdrawal, they are far more characteristic and severe in **Alcohol withdrawal** (Delirium Tremens) or stimulant withdrawal. **High-Yield Clinical Pearls for NEET-PG:** * **DSM-5 Criteria for CWS:** Requires at least 3 symptoms (Irritability, Anxiety, Sleep difficulty, Appetite change, Restlessness, Depressed mood, or Physical symptoms like sweating/fever/chills). * **Timeline:** Symptoms peak at **days 2–6** and usually resolve within 1–2 weeks. * **Treatment:** Most cases are mild and managed with supportive care. For severe symptoms, **Dronabinol** (synthetic THC) or Gabapentin may be used. * **Amotivational Syndrome:** A chronic effect of cannabis use characterized by apathy and lack of ambition, often tested alongside withdrawal.

Q: Cotton fever is a recognized complication associated with the abuse of which of the following substances?

Heroin. **Explanation:** **Cotton fever** is a benign, self-limiting febrile syndrome seen in intravenous (IV) drug users, most commonly associated with **Heroin** abuse. The condition occurs when drug users filter their dissolved heroin solution through a piece of cotton (often a cotton ball or cigarette filter) to remove impurities before injection. The "fever" is triggered by the accidental injection of tiny cotton fibers or, more commonly, **endotoxins** produced by the bacterium *Pantoea agglomerans*, which lives in the cotton plant. Within 10–20 minutes of injection, the patient develops a rapid onset of high fever, chills, tachycardia, and malaise. While it mimics sepsis, it typically resolves spontaneously within 24 hours with supportive care. **Analysis of Incorrect Options:** * **A. Amphetamine:** While often injected, the specific "cotton filter" practice and subsequent endotoxin reaction are classically described with heroin preparation. * **C. Phencyclidine (PCP):** PCP is primarily smoked, snorted, or ingested. Even when injected, it is not classically associated with the cotton fever phenomenon. * **D. Cocaine:** Although IV cocaine use carries risks of endocarditis and skin infections, cotton fever is specifically linked to the traditional preparation methods of heroin. **Clinical Pearls for NEET-PG:** * **Differential Diagnosis:** Cotton fever must be distinguished from **Infective Endocarditis** and **Sepsis**. The key differentiator is the rapid resolution (within 24 hours). * **Causative Agent:** *Pantoea agglomerans* (formerly *Enterobacter agglomerans*). * **Management:** Primarily supportive (antipyretics and hydration). Antibiotics are usually not required if the fever subsides quickly. * **Other Heroin Complications:** Look for pinpoint pupils (miosis), respiratory depression, and track marks.

Q: Which of the following is an alternative to methadone for maintenance treatment of opiate dependence?

Buprenorphine. ### Explanation **Correct Option: C. Buprenorphine** The primary goal of maintenance treatment in opioid dependence is to prevent withdrawal symptoms and reduce cravings using long-acting opioid agonists or partial agonists. **Buprenorphine** is a **partial μ-opioid receptor agonist** and a **κ-opioid receptor antagonist**. Due to its high affinity for the μ-receptor and its "ceiling effect" on respiratory depression, it is safer in overdose compared to full agonists like methadone. It has a long half-life (24–48 hours), allowing for once-daily or even alternate-day dosing, making it an ideal alternative to methadone for office-based maintenance therapy. **Analysis of Incorrect Options:** * **A & B (Diazepam and Chlordiazepoxide):** These are benzodiazepines used primarily for managing alcohol withdrawal and anxiety. They have no role in the maintenance treatment of opioid dependence and can actually increase the risk of fatal respiratory depression if used alongside opioids. * **D (Dextropropoxyphene):** While it is a weak opioid agonist previously used for mild pain and detoxification, it is not used for maintenance therapy due to its side effect profile (cardiotoxicity) and lower efficacy compared to buprenorphine or methadone. It has been banned/withdrawn in many regions. **High-Yield Clinical Pearls for NEET-PG:** * **Methadone:** A full μ-agonist; the gold standard for maintenance but requires strict supervision due to overdose risk and QTc prolongation. * **Naloxone:** Often added to buprenorphine (Suboxone) to prevent intravenous abuse; it has poor oral bioavailability but triggers withdrawal if injected. * **Clonidine:** An α2-agonist used to treat the *autonomic symptoms* of opioid withdrawal (tachycardia, hypertension, sweating) but does not treat cravings. * **Naltrexone:** An opioid antagonist used for relapse prevention *after* detoxification is complete.

Q: What is the treatment of alcohol withdrawal?

Benzodiazepine. **Explanation:** **1. Why Benzodiazepines (BZDs) are the Correct Answer:** Alcohol is a Central Nervous System (CNS) depressant that enhances GABA (inhibitory) activity and inhibits NMDA/Glutamate (excitatory) activity. Chronic use leads to downregulation of GABA receptors and upregulation of NMDA receptors. When alcohol is abruptly stopped, the brain enters a state of **hyperexcitability**. Benzodiazepines are the **gold standard** treatment because they show **cross-tolerance** with alcohol. They bind to GABA-A receptors, substituting for the missing alcohol effect, thereby preventing seizures, delirium tremens, and autonomic instability. **2. Why Other Options are Incorrect:** * **Beta-blockers (A):** While they can control autonomic symptoms (tachycardia, hypertension), they **do not prevent seizures or delirium tremens**. They may also mask the early warning signs of withdrawal. * **Amitriptyline (C) & SSRIs (D):** These are antidepressants. They have no role in acute withdrawal management. In fact, Tricyclic Antidepressants (TCAs) like Amitriptyline can lower the seizure threshold, making them dangerous during withdrawal. **3. NEET-PG High-Yield Clinical Pearls:** * **Drug of Choice (DOC):** Long-acting BZDs like **Chlordiazepoxide** or **Diazepam** are preferred due to smoother tapering. * **Liver Disease/Elderly:** Use **LOT** (Lorazepam, Oxazepam, Temazepam) as they undergo direct glucuronidation and do not have active metabolites. * **Symptom-Triggered Therapy:** The **CIWA-Ar scale** is used to monitor severity and guide BZD dosing. * **Wernicke’s Prophylaxis:** Always administer **Thiamine (Vitamin B1)** *before* Glucose to prevent Wernicke’s Encephalopathy.

Q: Lilliputian hallucinations are seen in which of the following conditions?

Alcohol withdrawal. **Explanation:** **Lilliputian hallucinations** are a specific type of visual hallucination where the patient perceives people, animals, or objects as being much smaller than their actual size (micropsia). 1. **Why Alcohol Withdrawal is Correct:** Lilliputian hallucinations are a hallmark feature of **Alcohol Withdrawal Delirium (Delirium Tremens)**. They typically occur 48–72 hours after the last drink. The underlying mechanism involves neuro-hyperexcitability due to the sudden removal of GABAergic inhibition and compensatory NMDA receptor upregulation. These hallucinations are often vivid and can be terrifying or amusing to the patient. 2. **Why Other Options are Incorrect:** * **Opioid Withdrawal:** Characterized by autonomic hyperactivity (mydriasis, lacrimation, rhinorrhea, piloerection) and intense physical pain, but visual hallucinations are not a standard feature. * **LSD Withdrawal:** LSD is a hallucinogen, but it does not typically produce a "withdrawal syndrome" characterized by hallucinations. Instead, it causes acute intoxication (perceptual distortions) or "flashbacks" (Hallucinogen Persisting Perception Disorder). * **Cocaine Withdrawal:** Primarily presents with "the crash"—dysphoria, fatigue, and increased appetite. While cocaine *intoxication* can cause tactile hallucinations (formication or "cocaine bugs"), withdrawal does not typically feature Lilliputian hallucinations. **High-Yield Clinical Pearls for NEET-PG:** * **Formication (Magnan’s Sign):** Tactile hallucinations (feeling bugs crawling under the skin) are classic for **Cocaine Intoxication**. * **Charles Bonnet Syndrome:** Visual hallucinations (often Lilliputian) occurring in elderly patients with significant visual impairment (e.g., macular degeneration) but intact cognition. * **Alice in Wonderland Syndrome:** Distortions of perception (micropsia/macropsia) often associated with **Migraines** or **Epilepsy**.

Question 1

Nicotine acts as an agonist for receptors of a particular neurotransmitter. The worsening of cognitive symptoms in persons with mild cognitive impairments who stop smoking is due to the effect on this neurotransmitter.

Accepted Answer

Acetylcholine

Answer

Dopamine

Answer

Neuropeptide Y

Answer

Nitric oxide

Question 2

Which is the most commonly abused opioid?

Accepted Answer

Diacetylmorphine

Answer

Morphine

Answer

Codeine

Answer

Fentanyl

Question 3

Korsakoff's psychosis is diagnosed by which of the following findings?

Accepted Answer

Impairment of long-term memory

Answer

Peripheral neuropathy

Answer

Visual hallucination

Answer

Seizures

Question 4

Which of the following is NOT a symptom of opioid withdrawal?

Accepted Answer

Polyuria

Answer

Yawning

Answer

Fever

Answer

Insomnia

Question 5

Three policemen, with difficulty, drag an agitated and very combative young man into an emergency room. Once there, he is restrained because he reacts with rage and tries to hit anyone who approaches him. When it is finally safe to approach him, the resident on call notices that the patient has very prominent vertical nystagmus. Shortly thereafter, the patient has a generalized seizure. Which of the following substances of abuse is the most likely to produce this presentation?

Accepted Answer

Cocaine

Answer

Amphetamine

Answer

PCP

Answer

Meperidine

Question 6

A 40-year-old patient, who has been consuming cannabis regularly for the past 20 years, presents with withdrawal symptoms. What is the most frequently observed withdrawal symptom?

Accepted Answer

Irritability

Answer

Yawning

Answer

Seizures

Answer

Tremors

Question 7

Cotton fever is a recognized complication associated with the abuse of which of the following substances?

Accepted Answer

Heroin

Answer

Amphetamine

Answer

Phencyclidine

Answer

Cocaine

Question 8

Which of the following is an alternative to methadone for maintenance treatment of opiate dependence?

Accepted Answer

Buprenorphine

Answer

Diazepam

Answer

Chlordiazepoxide

Answer

Dextropropoxyphene

Question 9

What is the treatment of alcohol withdrawal?

Accepted Answer

Benzodiazepine

Answer

Beta-blocker

Answer

Amitriptyline

Answer

SSRIs

Question 10

Lilliputian hallucinations are seen in which of the following conditions?

Accepted Answer

Alcohol withdrawal

Answer

Opioid withdrawal

Answer

LSD withdrawal

Answer

Cocaine withdrawal

Substance Use Disorders — MCQs

Substance Use Disorders — MCQs

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