Substance Use Disorders — MCQs

Substance Use Disorders Indian Medical PG Practice Questions and MCQs

Question 181: A male started consuming alcohol at 20 years of age and has been taking 3 quarters daily for the past 30 years. He now reports that he experiences the desired effect with only 1 quarter. What is the diagnosis?

A. Withdrawal
B. Mellanby phenomenon
C. Reverse tolerance (Correct Answer)
D. Cross tolerance

Explanation: ### Explanation **Correct Answer: C. Reverse tolerance** **Why it is correct:** Tolerance is defined as the need for increased amounts of a substance to achieve intoxication or the desired effect. However, in chronic, heavy alcohol users (like this patient with a 30-year history), the liver eventually suffers significant damage (cirrhosis or alcoholic hepatitis). This leads to a **decline in the liver's metabolic capacity** to break down alcohol. Consequently, even small amounts of alcohol remain in the bloodstream for longer periods, producing the desired effect or intoxication. This phenomenon, where a lower dose is required to produce the same effect previously achieved with higher doses, is known as **Reverse Tolerance**. **Why other options are incorrect:** * **Withdrawal:** Refers to the physical and psychological symptoms (e.g., tremors, seizures, delirium tremens) that occur when a person stops or reduces heavy alcohol intake. * **Mellanby Phenomenon:** This describes the observation that the effects of alcohol are more pronounced when blood alcohol levels are **rising** than when they are falling, even if the concentration is the same at both points. * **Cross Tolerance:** This occurs when tolerance to one drug (e.g., alcohol) leads to tolerance to another drug in the same class (e.g., benzodiazepines or barbiturates) due to similar mechanisms of action. **Clinical Pearls for NEET-PG:** * **Tolerance** is a hallmark of the "Dependence Syndrome" (ICD-10). * **Reverse tolerance** is specifically associated with **end-stage liver disease** in chronic alcoholics. * Remember the **CAGE questionnaire** for screening: **C**ut down, **A**nnoyed, **G**uilty, **E**ye-opener. * Alcohol metabolism follows **Zero-order kinetics** (a constant amount is eliminated per unit time, regardless of concentration).

Question 182: Diagnosis of Alcohol Dependence includes all of the following, EXCEPT?

A. Impaired occupational and social functioning
B. The need for daily drinking to function adequately
C. Lack of tolerance for alcohol (Correct Answer)
D. Inability to cut down or stop drinking

Explanation: To diagnose Alcohol Dependence (as per ICD-10 or DSM-IV criteria), specific patterns of behavior and physiological changes must be present. ### **Explanation of the Correct Answer** **Option C (Lack of tolerance for alcohol)** is the correct answer because it is the opposite of what occurs in dependence. **Tolerance** is a hallmark physiological feature of substance dependence, defined as either a need for markedly increased amounts of the substance to achieve intoxication or a markedly diminished effect with continued use of the same amount. A "lack of tolerance" would imply that the individual's sensitivity to alcohol remains unchanged or increases, which contradicts the neuroadaptation seen in chronic alcohol use. ### **Analysis of Incorrect Options** * **Option A (Impaired functioning):** This is a core feature of the "Social Impairment" cluster. Dependence leads to the neglect of alternative pleasures, interests, and major role obligations at work, school, or home. * **Option B (Daily drinking to function):** This reflects the "Compulsion" or "Loss of Control" aspect. The individual feels a strong desire or sense of compulsion to take the substance to maintain a baseline level of functioning. * **Option D (Inability to cut down):** This represents "Impaired Control." A persistent desire or unsuccessful efforts to cut down or control substance use is a primary diagnostic criterion. ### **High-Yield Clinical Pearls for NEET-PG** * **ICD-10 Criteria (The "3 out of 6" Rule):** Diagnosis requires ≥3 of the following in the last year: 1. Strong craving, 2. Impaired control, 3. Physiological withdrawal, 4. Tolerance, 5. Neglect of other interests, 6. Persistent use despite harm. * **CAGE Questionnaire:** The most sensitive screening tool (Cut down, Annoyed, Guilty, Eye-opener). A score of ≥2 is clinically significant. * **Wernicke’s Encephalopathy Triad:** Confusion, Ataxia, and Ophthalmoplegia (due to Thiamine/B1 deficiency). * **First-line Pharmacotherapy:** Naltrexone (reduces craving) and Acamprosate (maintains abstinence). Disulfiram is an aversive agent (aldehyde dehydrogenase inhibitor).

Question 183: What is commonly known as the 'rave drug'?

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

Explanation: **Explanation:** **Ecstasy (MDMA - Methylenedioxymethamphetamine)** is the correct answer. It is famously known as the **'rave drug'** or 'club drug' because of its stimulant and mildly hallucinogenic properties. It increases the release of serotonin, dopamine, and norepinephrine, leading to heightened sensory perception, increased energy, and feelings of euphoria and empathy. These effects make it popular in dance parties and raves. **Analysis of Incorrect Options:** * **Cannabis:** Known as a 'gateway drug.' It typically causes relaxation and altered time perception but lacks the intense stimulant properties associated with rave culture. * **Cocaine:** A potent stimulant known as 'Coke' or 'Snow.' While used recreationally, it is more commonly associated with binge patterns rather than the specific 'rave' subculture. * **Heroin:** An opioid known as 'Smack' or 'Horse.' It is a central nervous system depressant, causing sedation and respiratory depression, which is the opposite of the high-energy state sought at raves. **High-Yield Clinical Pearls for NEET-PG:** * **Mechanism:** MDMA primarily acts as a **serotonin-norepinephrine-dopamine releasing agent** and reuptake inhibitor. * **Life-threatening Complication:** **Malignant Hyperthermia** and profound dehydration are critical risks when used in crowded, hot environments (like raves). * **Hyponatremia:** MDMA can cause SIADH (Syndrome of Inappropriate Antidiuretic Hormone), which, combined with excessive water intake, leads to fatal hyponatremia. * **Bruxism:** A common side effect is jaw clenching (bruxism), which is why users often carry pacifiers or lollipops. * **Post-use 'Crash':** Users often experience a "Monday Blues" or "Suicide Tuesday" due to acute serotonin depletion.

Question 184: What is the most common feature of alcohol withdrawal?

A. Violent attitude
B. Hypertension
C. Tremors (Correct Answer)
D. Hyperventilation

Explanation: **Explanation:** Alcohol is a Central Nervous System (CNS) depressant that enhances GABAergic (inhibitory) activity and inhibits NMDA (excitatory) receptors. Chronic consumption leads to a compensatory down-regulation of GABA receptors and up-regulation of NMDA receptors. When alcohol is abruptly stopped, this results in **CNS hyperexcitability**, manifesting primarily as autonomic hyperactivity and motor disturbances. **Why Tremors are correct:** **Tremors** (specifically "generalized coarse tremors") are the **earliest and most common** sign of alcohol withdrawal. They typically appear within 6–12 hours after the last drink. Often referred to as "the shakes," they involve the hands, tongue, and eyelids. **Analysis of Incorrect Options:** * **Violent attitude:** While irritability and agitation are common, overt violence is not a cardinal or most frequent feature; it is more characteristic of alcohol intoxication or severe Delirium Tremens. * **Hypertension:** Autonomic hyperactivity (tachycardia, hypertension) does occur, but it is secondary to the generalized sympathetic surge and is less frequent than tremors. * **Hyperventilation:** This is not a classic feature of alcohol withdrawal; respiratory changes are usually minimal unless associated with severe metabolic derangement or anxiety. **High-Yield Facts for NEET-PG:** * **Timeline of Withdrawal:** * 6–12 hours: Insomnia, **Tremors**, anxiety, GI upset. * 12–24 hours: Alcoholic Hallucinosis (most commonly **Visual**). * 24–48 hours: Withdrawal Seizures (Rum fits; generalized tonic-clonic). * 48–72 hours: **Delirium Tremens** (Medical emergency: clouding of consciousness, autonomic instability). * **Drug of Choice:** Benzodiazepines (e.g., Chlordiazepoxide or Diazepam). For patients with liver failure, use **LOT** (Lorazepam, Oxazepam, Temazepam).

Question 185: Which of the following is NOT used for nicotine deaddiction?

A. Nicotine Patch
B. Nicotine Spray
C. Nicotine Inhaler
D. Nicotine subcutaneous Injection (Correct Answer)

Explanation: **Explanation:** The goal of **Nicotine Replacement Therapy (NRT)** is to provide a controlled dose of nicotine to relieve withdrawal symptoms while avoiding the rapid "spike" in blood nicotine levels that reinforces addiction. **Why Option D is Correct:** **Nicotine subcutaneous injections** are not used for deaddiction because they would cause a rapid rise in plasma nicotine levels, mimicking the pharmacokinetics of smoking. This high "bolus" effect maintains the addictive potential rather than tapering it. Furthermore, nicotine is highly irritating to tissues, making repeated injections impractical and painful. **Why Other Options are Incorrect:** * **A, B, & C (Patch, Spray, Inhaler):** These are all FDA-approved forms of NRT. They deliver nicotine through mucosal or transdermal routes, ensuring a slower, more stable rise in plasma concentration compared to smoking. * **Nicotine Patch:** Provides the most stable, long-acting basal level of nicotine. * **Nicotine Spray/Inhaler:** These are short-acting methods used to manage acute cravings (breakthrough symptoms). **High-Yield Clinical Pearls for NEET-PG:** * **First-line Pharmacotherapy:** Includes NRT, **Varenicline** (most effective monotherapy; a partial agonist at $\alpha4\beta2$ nicotinic receptors), and **Bupropion** (an atypical antidepressant). * **Varenicline Side Effects:** Most common is nausea; historically linked to neuropsychiatric symptoms (though recent data suggests it is safer than previously thought). * **Bupropion Contraindications:** Avoid in patients with a history of seizures or eating disorders (Bulimia/Anorexia), as it lowers the seizure threshold. * **Mechanism:** NRT works by stimulating nicotinic acetylcholine receptors in the ventral tegmental area, reducing the withdrawal-induced dopamine drop.

Question 186: The Cage test is used for the diagnosis of which of the following?

A. Opioid abuse
B. Schizophrenia
C. Alcoholism (Correct Answer)
D. Paranoid Psychosis

Explanation: **Explanation:** The **CAGE questionnaire** is a globally recognized, high-yield screening tool used specifically for **Alcohol Use Disorder (Alcoholism)**. It is designed to identify problematic drinking patterns rather than the quantity of alcohol consumed. The acronym **CAGE** stands for: * **C (Cut down):** Have you ever felt you should cut down on your drinking? * **A (Annoyed):** Have people annoyed you by criticizing your drinking? * **G (Guilty):** Have you ever felt bad or guilty about your drinking? * **E (Eye-opener):** Have you ever had a drink first thing in the morning to steady your nerves or get rid of a hangover? A score of **2 or more** is considered clinically significant, indicating a high probability of alcohol dependence. **Analysis of Incorrect Options:** * **Opioid abuse:** Screening for opioid use usually involves the DAST (Drug Abuse Screening Test) or clinical assessment of withdrawal/intoxication signs. * **Schizophrenia:** This is a primary psychotic disorder diagnosed using ICD-11 or DSM-5 criteria (e.g., delusions, hallucinations, disorganized speech) lasting at least 1–6 months. * **Paranoid Psychosis:** This is a symptom or subtype of delusional disorder/schizophrenia and is diagnosed through clinical psychiatric evaluation, not a four-question screening tool. **High-Yield Clinical Pearls for NEET-PG:** 1. **Sensitivity:** CAGE is highly sensitive for detecting dependence but less sensitive for "at-risk" drinking. 2. **T-ACE & AUDIT:** The **AUDIT** (Alcohol Use Disorders Identification Test) is the "Gold Standard" for screening in primary care. **T-ACE** is a modified version used specifically for pregnant women. 3. **CIWA-Ar:** This scale is used to monitor the severity of **Alcohol Withdrawal**, not for initial screening/diagnosis.

Question 187: Which of the following is the mechanism of action of Antabuse?

A. Inhibits glucuronide conjugation
B. Inhibits oxidation of alcohol (Correct Answer)
C. Inhibits excretion of alcohol through the kidney
D. None of the above

Explanation: **Explanation:** **Antabuse (Disulfiram)** is a classic example of **Aversion Therapy** used in the treatment of alcohol dependence. To understand its mechanism, one must look at the normal metabolism of alcohol: 1. Alcohol is converted to **Acetaldehyde** by the enzyme *Alcohol Dehydrogenase*. 2. Acetaldehyde is then converted to **Acetic Acid** by the enzyme **Aldehyde Dehydrogenase (ALDH)**. Disulfiram works by **irreversibly inhibiting the enzyme Aldehyde Dehydrogenase**. This prevents the further oxidation of acetaldehyde, leading to its accumulation in the body (up to 5–10 times higher than normal). This accumulation results in the **Disulfiram-Ethanol Reaction (DER)**, characterized by flushing, tachycardia, nausea, vomiting, and hypotension, which deters the patient from drinking. **Analysis of Options:** * **Option A (Inhibits glucuronide conjugation):** This is incorrect. Glucuronidation is a Phase II metabolic reaction; while some alcohol is excreted as ethyl glucuronide, it is a minor pathway and not the target of Antabuse. * **Option B (Inhibits oxidation of alcohol):** This is **Correct**. By blocking the conversion of acetaldehyde to acetic acid, it halts the oxidative pathway of alcohol metabolism. * **Option C (Inhibits excretion):** This is incorrect. Alcohol is primarily metabolized by the liver (90%) and excreted via lungs and kidneys; Antabuse does not interfere with the physical excretion process. **High-Yield Clinical Pearls for NEET-PG:** * **The "Disulfiram-like Reaction":** Several other drugs can cause a similar reaction when taken with alcohol, most notably **Metronidazole**, Griseofulvin, and certain Cephalosporins (e.g., Cefotetan). * **Contraindications:** It should never be administered to a patient in a state of alcohol intoxication or without their full knowledge. It is contraindicated in patients with severe cardiac disease or psychosis. * **Monitoring:** Baseline and periodic **Liver Function Tests (LFTs)** are essential due to the risk of hepatotoxicity.

Question 188: What is the recommended daily dose of thiamine for patients with delirium tremens?

A. 100-200 mg per oral or parenteral daily
B. 250 mg per oral or parenteral daily for the first 3-5 days (Correct Answer)
C. 400 mg per oral or parenteral daily
D. 500 mg per oral or parenteral daily

Explanation: **Explanation:** In patients with **Delirium Tremens (DT)** or severe alcohol withdrawal, there is a high risk of underlying **Wernicke’s Encephalopathy (WE)** due to chronic thiamine (Vitamin B1) deficiency. Thiamine is a critical cofactor for glucose metabolism; without it, neuronal death occurs in the mammillary bodies and thalamus. **Why Option B is Correct:** Current clinical guidelines (including those often cited in psychiatric textbooks like Kaplan & Sadock) recommend a prophylactic or therapeutic dose of **250 mg of thiamine** administered parenterally (IM/IV) or orally once daily for the first **3 to 5 days** of withdrawal management. This dose is sufficient to prevent the onset of Wernicke-Korsakoff Syndrome during the acute metabolic stress of delirium tremens. **Analysis of Incorrect Options:** * **Option A (100-200 mg):** While 100 mg is often used for routine nutritional supplementation, it is considered inadequate for the high-demand state of Delirium Tremens or suspected WE. * **Options C & D (400-500 mg):** While higher doses (500 mg TDS) are the gold standard for *confirmed* Wernicke’s Encephalopathy, 250 mg is the standard recommendation for the general management of withdrawal/DT in most standard Indian medical curricula and exams. **High-Yield Clinical Pearls for NEET-PG:** * **The "Glucose Rule":** Always administer thiamine **before** or concurrently with IV glucose. Giving glucose first can precipitate Wernicke’s Encephalopathy by consuming the last remaining stores of thiamine. * **Wernicke’s Triad:** Confusion, Ataxia, and Ophthalmoplegia (usually 6th nerve palsy). * **Korsakoff Psychosis:** Characterized by anterograde amnesia and **confabulation** (filling memory gaps with fabricated stories). * **Drug of Choice for DT:** Benzodiazepines (e.g., Diazepam or Lorazepam).

Question 189: The Audit test is used for the screening of which of the following conditions?

A. Alcohol use disorder (Correct Answer)
B. Opioid use disorder
C. Sexual abuse
D. Cannabis abuse

Explanation: **Explanation:** The **AUDIT (Alcohol Use Disorders Identification Test)** is a 10-item screening tool developed by the World Health Organization (WHO) to assess alcohol consumption, drinking behaviors, and alcohol-related problems. It is considered the "gold standard" for screening in primary care settings because it can detect both hazardous drinking and fully developed dependence. **Analysis of Options:** * **A. Alcohol use disorder (Correct):** AUDIT specifically evaluates three domains: hazardous alcohol use, dependence symptoms, and harmful alcohol use. A score of **8 or more** in men (7 in women) is generally indicative of hazardous or harmful alcohol use. * **B. Opioid use disorder:** Screening for opioids often utilizes the **DAST-10** (Drug Abuse Screening Test) or the **COWS** (Clinical Opiate Withdrawal Scale) for assessment of withdrawal severity. * **C. Sexual abuse:** Screening involves clinical interviews or specific trauma-informed tools like the **HITS** (Hurt, Insult, Threaten, Scream) for domestic violence, but not AUDIT. * **D. Cannabis abuse:** Similar to opioids, cannabis use is typically screened using the **ASSIST** (Alcohol, Smoking, and Substance Involvement Screening Test) or the **CUDIT-R** (Cannabis Use Disorder Identification Test - Revised). **High-Yield Clinical Pearls for NEET-PG:** * **CAGE Questionnaire:** A shorter 4-item screen for alcohol (Cut down, Annoyed, Guilty, Eye-opener). A score of $\geq$ 2 is significant. * **ASSIST:** Developed by WHO to screen for *all* psychoactive substances (tobacco, alcohol, and illicit drugs). * **Gold Standard for Alcohol Withdrawal:** **CIWA-Ar** (Clinical Institute Withdrawal Assessment for Alcohol). * **Biochemical Marker:** **GGT** (Gamma-glutamyl transferase) is the most sensitive lab marker for chronic heavy drinking, while **Carbohydrate Deficient Transferrin (CDT)** is the most specific.

Question 190: A 20-year-old man presents with symptoms suggestive of acute stimulant intoxication. Which of the following conditions do his symptoms most closely resemble?

A. Alcohol intoxication
B. Antisocial personality disorder
C. Mania (Correct Answer)
D. Obsessive-compulsive disorder

Explanation: **Explanation:** The correct answer is **Mania**. **Why Mania is correct:** Acute stimulant intoxication (caused by substances like cocaine or amphetamines) results in a massive surge of catecholamines (dopamine and norepinephrine) in the brain. This physiological state creates a clinical picture that is almost indistinguishable from a manic episode. Common shared features include **euphoria, increased energy, psychomotor agitation, pressured speech, decreased need for sleep, grandiosity, and heightened sympathetic activity** (tachycardia, pupillary dilation). In severe cases, both can present with paranoid delusions or hallucinations. **Why other options are incorrect:** * **Alcohol intoxication:** This typically presents with CNS depression, slurred speech, ataxia, and disinhibition, which is the opposite of the hyper-aroused state seen in stimulant use. * **Antisocial personality disorder (ASPD):** While individuals with ASPD have higher rates of substance abuse, the disorder itself is a chronic pattern of behavior (disregard for rules, lack of empathy) rather than an acute symptomatic state. * **Obsessive-compulsive disorder (OCD):** OCD is characterized by intrusive thoughts and repetitive rituals. It does not feature the euphoria or sympathetic overactivity characteristic of stimulants. **High-Yield Clinical Pearls for NEET-PG:** * **Pupillary Sign:** Stimulant intoxication causes **Mydriasis** (dilated pupils), whereas Opioid intoxication causes **Miosis** (pinpoint pupils). * **Cocaine vs. Amphetamine:** Cocaine has a shorter half-life and is associated with "formication" (the sensation of bugs crawling on skin, known as **Cocaine bugs** or Magnan’s sign). * **Treatment:** The first-line management for acute stimulant-induced agitation or psychosis is **Benzodiazepines** (e.g., Lorazepam). Avoid beta-blockers alone due to the risk of unopposed alpha-adrenergic stimulation.

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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