Psychotic Disorders Practice Questions

Q: What is the percentage of monozygotic twins who develop schizophrenia?

50%. ### Explanation The correct answer is **D. 50%**. Schizophrenia has a strong genetic component, and the risk of developing the disorder increases with the degree of genetic relatedness to an affected individual. Since **monozygotic (MZ) twins** share 100% of their genetic material, they have the highest concordance rate for schizophrenia, which is approximately **40% to 50%**. This high percentage underscores the significant role of genetics in the etiology of the disease. #### Analysis of Options: * **A. 0.10%:** This is significantly lower than the risk in the general population. * **B. 1%:** This represents the **lifetime prevalence** of schizophrenia in the **general population**. * **C. 10%:** This is the approximate risk for **first-degree relatives** (e.g., children of one affected parent or dizygotic/fraternal twins who share 50% of their genes). * **D. 50%:** This is the established concordance rate for monozygotic twins. Note that because it is not 100%, it also proves that environmental factors play a crucial role. #### High-Yield Clinical Pearls for NEET-PG: * **Highest Risk:** The highest risk of developing schizophrenia is in an individual with **two affected parents (approx. 40-46%)** or a **monozygotic twin (approx. 47-50%)**. * **Dizygotic (DZ) Twins:** The risk is approximately **12-15%**. * **Sibling Risk:** If one sibling is affected, the risk for another sibling is about **10%**. * **Second-degree relatives:** The risk drops to approximately **2-3%**. * **Key Concept:** If a question asks for the "most important factor" in the etiology of schizophrenia, the answer is **Genetics**.

Q: Ekbom syndrome is referred to as:

Delusion of infestation. **Explanation:** **Ekbom syndrome**, also known as **Delusional Parasitosis** or **Delusion of Infestation**, is a monosymptomatic hypochondriacal psychosis. Patients hold a fixed, false belief (delusion) that they are infested with small living organisms like insects, lice, worms, or mites, despite medical evidence to the contrary. * **Why Option A is correct:** The hallmark of Ekbom syndrome is the patient's conviction of being infested. Patients often present with the **"Matchbox Sign"** (or "Ziploc bag sign"), where they bring samples of skin debris, lint, or dust to the clinic, claiming they are the parasites. * **Why Option B is incorrect:** **Delusion of persecution** is the belief that one is being conspired against or harmed (common in Schizophrenia). * **Why Option C is incorrect:** **Delusion of love** is known as **De Clerambault’s syndrome** (Erotomania), where a patient believes a person of higher status is in love with them. * **Why Option D is incorrect:** **Delusion of infidelity** is known as **Othello syndrome**, characterized by the irrational belief that one’s partner is being unfaithful. **High-Yield Clinical Pearls for NEET-PG:** 1. **Formication:** The tactile hallucination of insects crawling on or under the skin (often associated with Ekbom syndrome or Cocaine/Amphetamine withdrawal). 2. **Treatment:** The drug of choice is typically an atypical antipsychotic like **Risperidone**. Historically, **Pimozide** was the gold standard. 3. **Differential:** It must be distinguished from organic causes like Vitamin B12 deficiency or drug-induced states.

Q: Monosymptomatic hypochondriasis means:

Somatic type delusional disorder. **Explanation:** **Monosymptomatic hypochondriasis** is a term historically used to describe a condition where a patient holds a single, fixed, false belief (delusion) regarding their physical health or bodily functions, despite medical reassurance. In modern psychiatric classification (DSM-5/ICD-11), this is categorized as **Somatic type Delusional Disorder**. **Why the correct answer is right:** In Somatic type delusional disorder, the delusion is limited to physical sensations or abnormalities (e.g., believing one emits a foul odor, is infested with parasites, or has misshapen body parts). Unlike "Hypochondriasis" (Illness Anxiety Disorder), where there is a *fear* of having a disease, in Monosymptomatic Hypochondriasis, there is a *conviction* that the disease or defect is present. **Analysis of incorrect options:** * **Paranoid type (Persecutory):** The central theme is being conspired against, cheated, or harassed. * **De Clerambault syndrome (Erotomania):** The delusion that another person, usually of higher status, is in love with the patient. * **Othello syndrome (Morbid Jealousy):** The delusion that one’s spouse or partner is unfaithful. **High-Yield Clinical Pearls for NEET-PG:** * **Ekbom Syndrome:** A specific form of somatic delusional disorder where patients believe they are infested with insects (Delusional Parasitosis). * **Key Distinction:** Delusional disorder is characterized by **non-bizarre delusions** (situations that could occur in real life) and the absence of other prominent psychotic symptoms like hallucinations or thought disorder. * **Treatment:** Second-generation antipsychotics (e.g., Risperidone) are the first-line treatment. Historically, Pimozide was considered the drug of choice for the somatic type.

Q: What is the incidence rate of schizophrenia in the general population?

0.50%. **Explanation:** The correct answer is **0.50%**. In psychiatry, it is crucial to distinguish between **incidence** (the rate of new cases occurring over a specific period) and **prevalence** (the total number of cases existing in a population at a given time). 1. **Why A is correct:** The annual **incidence** of schizophrenia is relatively low, typically cited as **0.5 to 1 per 10,000 adults**, which translates to a cumulative incidence of approximately **0.5%** over a lifetime. While some older texts used broader ranges, current epidemiological standards for NEET-PG emphasize this lower figure for incidence. 2. **Why B is incorrect:** **1%** is the classic figure for the **Lifetime Prevalence** of schizophrenia worldwide. This is a common "trap" in exams; students often confuse the total burden of the disease (prevalence) with the rate of new cases (incidence). 3. **Why C & D are incorrect:** Rates of **1.5% to 2%** are significantly higher than the established global average for schizophrenia. Such high figures are generally only seen in specific high-risk cohorts (e.g., children of one affected parent) rather than the general population. **High-Yield Clinical Pearls for NEET-PG:** * **Prevalence:** ~1% (Lifetime); ~0.5% (Point prevalence). * **Incidence:** ~0.5% (Cumulative). * **Gender:** Incidence is roughly equal in males and females, but males have an earlier onset (15–25 years) compared to females (25–35 years). * **Genetic Risk:** The highest risk is in **Monozygotic twins (47-50%)**, followed by children of two affected parents (40-46%). If one sibling has schizophrenia, the risk to another sibling is ~10%.

Q: Psychosis is NOT associated with which of the following?

Phobia. ### Explanation The core feature of **Psychosis** is the **loss of contact with reality**. This is clinically characterized by the presence of delusions, hallucinations, and a lack of insight. **1. Why Phobia is the Correct Answer:** A **Phobia** is an **Anxiety Disorder**, not a psychotic one. In phobias, the patient experiences an irrational, persistent fear of an object or situation. Crucially, the **insight is preserved**—the patient recognizes that their fear is excessive or unreasonable. Because reality testing remains intact, it is classified as a neurotic disorder rather than a psychotic one. **2. Analysis of Incorrect Options:** * **Delusion (A):** This is a hallmark of psychosis. It is defined as a fixed, false belief that is out of keeping with the patient’s social and cultural background and cannot be corrected by logic. * **Depression (B):** Severe depression can present with **psychotic features** (e.g., nihilistic delusions or auditory hallucinations). This is termed "Psychotic Depression." * **Mania (C):** Acute manic episodes in Bipolar Disorder often involve psychotic symptoms, most commonly **delusions of grandeur** or flight of ideas reaching a psychotic intensity. **Clinical Pearls for NEET-PG:** * **Insight:** The presence of insight usually distinguishes Neurosis (Anxiety, Phobia, OCD) from Psychosis (Schizophrenia, Mania). * **Schneider’s First Rank Symptoms (FRS):** These are high-yield diagnostic criteria for Schizophrenia (a primary psychotic disorder). * **Formal Thought Disorder:** Often seen in psychosis (e.g., loosening of associations), whereas thought processes in phobias are logical but anxiety-driven.

Q: A 40-year-old air-conditioner technician is referred to a psychiatrist because of a change in behavior and deterioration in functioning. When he feels the gust of cold air coming from the air conditioner, he interprets the cold air as poison gas from Mars. This phenomenon can be described as?

Delusional perception. ### Explanation The correct answer is **Delusional perception**. **1. Why Delusional Perception is Correct:** Delusional perception is a **primary delusion** and one of **Schneider’s First Rank Symptoms (SFRS)** of schizophrenia. It occurs in two stages: * **Stage 1:** A normal, real perception occurs (the technician feels the cold air). * **Stage 2:** A delusional, private, and highly significant meaning is attached to that perception (the air is "poison gas from Mars"). There is no logical connection between the perception and the interpretation. In this case, the sensory stimulus (cold air) is real and correctly identified, but the meaning attributed to it is delusional. **2. Analysis of Incorrect Options:** * **A. Delusional memory:** This is a delusion triggered by a past memory (e.g., "I remember when I was five, the doctor gave me a shot; that’s when they implanted the tracking chip"). * **C. Tactile hallucination:** A hallucination is a perception in the *absence* of an external stimulus. Here, the stimulus (cold air) is present; the error lies in the *interpretation*, not the perception itself. * **D. Primary delusion:** While delusional perception is a *type* of primary delusion, "Delusional perception" is the most specific and accurate phenomenological term for this two-stage process. **3. Clinical Pearls for NEET-PG:** * **Schneider’s First Rank Symptoms (SFRS):** Includes delusional perception, somatic passivity, thought insertion/withdrawal/broadcast, and specific auditory hallucinations (third-person, running commentary). * **The "Two-Membered" Process:** Always look for the link between a real stimulus and a bizarre meaning to identify delusional perception. * **Primary vs. Secondary Delusions:** Primary delusions (Autochthonous) arise suddenly ("out of the blue"), whereas secondary delusions are understandable in the context of other symptoms like mood or hallucinations.

Q: What is "Folie à deux"?

Shared delusion with another person. **Explanation:** **Folie à deux** (literally "madness of two") is a rare clinical syndrome, now classified in the DSM-5 under "Other Specified Schizophrenia Spectrum and Other Psychotic Disorder." It occurs when a symptom of psychosis—most commonly a **delusion**—is transmitted from one individual (the "primary" or "inducer") to another (the "secondary" or "recipient"). This typically happens between two people who share a close emotional bond and live in relative social isolation. **Why the other options are incorrect:** * **Option A (Delusion of doubles):** This refers to **Capgras Syndrome**, a delusional misidentification where a person believes a close relative or friend has been replaced by an identical-looking impostor. * **Option B (Substance abuse disorder):** While substance use can induce psychosis, Folie à deux is a primary psychological phenomenon based on interpersonal dynamics, not chemical intoxication. * **Option D (Dissociative disorder):** These disorders involve a breakdown of memory, identity, or perception (e.g., Dissociative Amnesia or DID) and do not typically involve the shared delusional content characteristic of Folie à deux. **NEET-PG High-Yield Pearls:** * **Synonym:** It is also known as **Shared Psychotic Disorder**. * **Management:** The primary step in management is **separating the two individuals**. Often, the delusion in the "secondary" person resolves once they are removed from the influence of the "primary" inducer. * **The Inducer:** Usually has a chronic psychotic illness (like Schizophrenia) and is the more dominant personality in the relationship. * **Variations:** If shared by more than two people, it is called *folie à trois*, *folie à quatre*, or *folie à plusieurs* (madness of many).

Question 1

A 41-year-old woman believes that her management has fabricated negative reports about her competence and forged her signature on sensitive documents to undermine her. She has reported this to the police and requested security, yet she continues to attend work and manage her household. She is suffering from:

Accepted Answer

Persistent Delusional Disorder

Answer

Late onset Psychosis

Answer

Paranoid Schizophrenia

Answer

Obsessive Compulsive Disorder

Question 2

Schizophrenia is characterized by which of the following?

Accepted Answer

Altered sensorium

Answer

Formal thought disorder

Answer

Delusion of reference

Answer

Waxy flexibility

Question 3

A man hits his neighbour. The next day, he feels that the police are pursuing him and that his brain is being controlled by radio waves transmitted by his neighbour. What is the probable diagnosis?

Accepted Answer

Delusion of persecution

Answer

Thought insertion

Answer

Passivity feeling

Answer

Obsessive-Compulsive Disorder

Question 4

What is the percentage of monozygotic twins who develop schizophrenia?

Accepted Answer

50%

Answer

0.10%

Answer

1%

Answer

10%

Question 5

Ekbom syndrome is referred to as:

Accepted Answer

Delusion of infestation

Answer

Delusion of persecution

Answer

Delusion of love

Answer

Delusion of infidelity

Question 6

Monosymptomatic hypochondriasis means:

Accepted Answer

Somatic type delusional disorder

Answer

Paranoid type delusional disorder

Answer

De Clerambault syndrome

Answer

Othello syndrome

Question 7

What is the incidence rate of schizophrenia in the general population?

Accepted Answer

0.50%

Answer

1%

Answer

1.50%

Answer

2%

Question 8

Psychosis is NOT associated with which of the following?

Accepted Answer

Phobia

Answer

Delusion

Answer

Depression

Answer

Mania

Question 9

A 40-year-old air-conditioner technician is referred to a psychiatrist because of a change in behavior and deterioration in functioning. When he feels the gust of cold air coming from the air conditioner, he interprets the cold air as poison gas from Mars. This phenomenon can be described as?

Accepted Answer

Delusional perception

Answer

Delusional memory

Answer

Tactile hallucination

Answer

Primary delusion

Question 10

What is "Folie à deux"?

Accepted Answer

Shared delusion with another person

Answer

Delusion of doubles

Answer

Substance abuse disorder

Answer

Dissociative disorder

Psychotic Disorders — MCQs

Psychotic Disorders — MCQs

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