Circadian Rhythms and Psychiatry — MCQs
Which condition is associated with periodic discharges on EEG at 4-second intervals?
What is the most reliable diagnostic tool to differentiate between psychological and organic erectile dysfunction?
Melatonin is secreted by
All of the following factors are involved in altered patterns of hormone release except
Hormonal secretions are tightly controlled by the time of day due to an inbuilt biological clock in human body. This rhythmic secretion is controlled by:
All are used in the treatment of nocturnal enuresis except?
Appetite is stimulated by all except
Which of the following is false about bipolar disorder?
What is the primary characteristic feature of Klein-Levin syndrome?
A 45-year-old male's blood test shows an increase in Homovanillic acid (HVA). Which of the following conditions is this finding most likely associated with?
Circadian Rhythms and Psychiatry Indian Medical PG Practice Questions and MCQs
Question 1: Which condition is associated with periodic discharges on EEG at 4-second intervals?
- A. SSPE (Correct Answer)
- B. Absence Seizure
- C. REM sleep disorder
- D. Focal epilepsy
Explanation: ***SSPE*** - **Subacute sclerosing panencephalitis (SSPE)** is a rare, fatal, progressive brain disorder characterized by inflammation and degeneration of the brain. - The distinctive EEG pattern consists of **periodic high-amplitude, slow-wave complexes** that recur every 4-15 seconds, often every 4-8 seconds, making 4-second intervals a key indicator. *Absence Seizure* - Absence seizures typically manifest as **brief staring spells** with impaired consciousness, lasting only a few seconds. - The EEG in absence seizures shows characteristic **generalized 3-Hz spike-and-wave discharges**, not 4-second interval periodic discharges. *REM sleep disorder* - **REM sleep behavior disorder** involves the acting out of vivid dreams due to the absence of normal muscle atonia during REM sleep [1]. - EEG in REM sleep behavior disorder shows normal sleep architecture but may include evidence of **muscle activity (EMG)** during REM sleep, not periodic discharges [1]. *Focal epilepsy* - **Focal epilepsy** originates in a specific area of the brain, causing seizures with symptoms dependent on the affected region [2]. - EEG findings in focal epilepsy typically show **interictal spikes or sharp waves** localized to the region of seizure onset, which are distinct from generalized periodic discharges [2].
Question 2: What is the most reliable diagnostic tool to differentiate between psychological and organic erectile dysfunction?
- A. Nocturnal penile tumescence (Correct Answer)
- B. PIPE therapy
- C. Sildenafil induced erection
- D. Squeeze technique
Explanation: ***Nocturnal penile tumescence*** - This diagnostic tool assesses whether a man experiences erections during sleep, which are naturally occurring physiological events. The presence of normal nocturnal erections indicates intact **neurovascular pathways** necessary for erection, suggesting that any daytime erectile dysfunction is likely due to **psychological factors** [2]. - Conversely, the absence of nocturnal erections points towards an **organic cause** for erectile dysfunction, as the physiological mechanism itself is impaired [1]. *Squeeze technique* - The squeeze technique is a behavioral therapy used to treat **premature ejaculation**, not erectile dysfunction. It involves stopping stimulation at the point of impending ejaculation and applying pressure to the glans to reduce arousal. - This technique does not provide any diagnostic information regarding the underlying cause (psychological vs. organic) of erectile dysfunction. *Sildenafil induced erection* - While sildenafil (Viagra) can induce an erection in many men with erectile dysfunction, its response does not reliably differentiate between psychological and organic causes. Sildenafil works by enhancing the effects of **nitric oxide**, leading to increased blood flow to the penis. - Both men with psychological erectile dysfunction and some with organic causes (e.g., mild vascular compromise) may respond to sildenafil, so a positive response does not rule out an **organic etiology**. *PIPE therapy* - "PIPE therapy" is not a recognized medical or diagnostic term for erectile dysfunction. It may be a typo or a misnomer. - Therefore, it does not serve as a diagnostic tool for differentiating between psychological and organic causes of erectile dysfunction.
Question 3: Melatonin is secreted by
- A. Melanocytes
- B. Pineal gland (Correct Answer)
- C. Hypothalamus
- D. Adrenal cortex
Explanation: ***Pineal gland*** - The **pineal gland** is a small endocrine gland located in the brain that primarily produces **melatonin**. - Its main function is to regulate **sleep-wake cycles** (circadian rhythms), with melatonin secretion increasing in darkness. *Melanocytes* - **Melanocytes** are cells found in the skin and eyes that produce **melanin**, a pigment responsible for skin, hair, and eye color. - They are not involved in the production of melatonin. *Hypothalamus* - The **hypothalamus** is a crucial part of the brain that links the nervous system to the endocrine system via the pituitary gland. - It produces various **releasing and inhibiting hormones** that control other glands, but it does not secrete melatonin. *Adrenal cortex* - The **adrenal cortex** is the outer part of the adrenal gland, responsible for producing **steroid hormones** like glucocorticoids (e.g., cortisol) and mineralocorticoids (e.g., aldosterone). - It does not produce melatonin; melatonin production is distinctly associated with the pineal gland.
Question 4: All of the following factors are involved in altered patterns of hormone release except
- A. Day time duties (Correct Answer)
- B. Travel across time zones
- C. Aging
- D. Lights on throughout 24 hours of the day
Explanation: **Day time duties** - **Daytime duties** are part of normal diurnal rhythms and do not inherently alter the **circadian clock** or hormone release patterns. - While they coincide with certain hormone fluctuations, they are not a disruptive factor like the other options. *Travel across time zones* - **Travel across time zones** causes **jet lag**, disrupting the body's internal clock and desynchronizing **circadian rhythms**. - This desynchronization directly affects the timing and amount of various hormones released, such as **cortisol** and **melatonin**. *Aging* - **Aging** brings about natural changes in hormone production and release patterns, including decreases in **growth hormone**, **sex hormones**, and alterations in **cortisol** rhythms. - These changes are a physiological consequence of the aging process, leading to altered hormonal profiles. *Lights on throughout 24 hours of the day* - Prolonged exposure to **light at night** disrupts the natural **sleep-wake cycle** and suppresses **melatonin** production, a key hormone for regulating circadian rhythms. - This constant light exposure can significantly alter the release of numerous other hormones that follow a **diurnal pattern**.
Question 5: Hormonal secretions are tightly controlled by the time of day due to an inbuilt biological clock in human body. This rhythmic secretion is controlled by:
- A. Ventrolateral nucleus
- B. Supraoptic nucleus
- C. Suprachiasmatic nucleus (Correct Answer)
- D. Posterolateral nucleus
Explanation: ***Suprachiasmatic nucleus*** - The **suprachiasmatic nucleus (SCN)**, located in the hypothalamus, is the primary pacemaker of the body's **circadian rhythms**, controlling the timing of hormonal secretions, sleep-wake cycles, and other daily oscillations. - It receives direct input from the **retina** about light-dark cycles, allowing it to synchronize the body's internal clock with the external environment. *Ventrolateral nucleus* - The **ventrolateral preoptic nucleus (VLPO)** is involved in **sleep regulation** and promoting non-REM sleep, but it does not act as the primary circadian pacemaker. - It receives input from the SCN and collaborates in regulating sleep, but its role is primarily inhibitory to wakefulness. *Supraoptic nucleus* - The **supraoptic nucleus** is primarily involved in the production and secretion of **vasopressin (ADH)** and **oxytocin**, which are neurohormones regulating fluid balance and social bonding, respectively. - It does not directly control the rhythmic aspect of general hormonal secretions or act as the central circadian clock. *Posterolateral nucleus* - This term is less commonly used in the context of circadian rhythm control; however, if referring to a thalamic nucleus, the **posterolateral nucleus** is generally associated with sensory processing, particularly somatosensory information. - It has no known role as a central pacemaker for hormonal secretions or circadian rhythms.
Question 6: All are used in the treatment of nocturnal enuresis except?
- A. Voiding of urine before sleeping (Correct Answer)
- B. Imipramine
- C. Alarm setup
- D. Maintenance of calendar of day night wetting
Explanation: ***Voiding of urine before sleeping*** - **Voiding before sleep** is a **general hygiene measure and preventive advice** rather than a specific therapeutic intervention for nocturnal enuresis. - While it may reduce bladder volume at bedtime, it does **not address the underlying pathophysiology** of nocturnal enuresis (arousal deficit, nocturnal polyuria, or detrusor overactivity). - It is **routine advice** given to all children, not a targeted treatment modality for curing enuresis. *Imipramine* - **Imipramine**, a tricyclic antidepressant, is an established **pharmacological treatment** for nocturnal enuresis. - Its mechanisms include: **anticholinergic effects** (increasing bladder capacity and functional bladder capacity), **alpha-adrenergic effects** (increasing bladder outlet resistance), and **antidiuretic effects**. - Typical dosing: **25-50 mg at bedtime**, with success rates of 40-60%. *Alarm setup* - **Bed-wetting alarms** are the **first-line behavioral therapy** with the highest long-term cure rates (60-70% success). - Works through **classical conditioning**: the alarm triggers when moisture is detected, training the child to either wake to void or develop nocturnal bladder control. - Requires **8-12 weeks** of consistent use and has the lowest relapse rates among treatments. *Maintenance of calendar of day night wetting* - **Voiding diary/calendar** is an essential **behavioral intervention** for monitoring and managing nocturnal enuresis. - Helps identify patterns, track treatment progress, and provides **positive reinforcement** through visual feedback. - Part of comprehensive behavioral management alongside fluid restriction and scheduled voiding during daytime.
Question 7: Appetite is stimulated by all except
- A. Neuropeptide Y
- B. Agouti related peptide
- C. Melanocyte concentrating hormone
- D. Melanocyte stimulating hormone (Correct Answer)
Explanation: ***Melanocyte stimulating hormone*** - **Alpha-melanocyte stimulating hormone (α-MSH)** is a catabolic hormone that acts to reduce appetite and increase energy expenditure. - It is an **anorexigenic peptide** that suppresses feeding by binding to central melanocortin receptors, primarily MC4R. *Neuropeptide Y* - **Neuropeptide Y (NPY)** is a potent **orexigenic peptide** that stimulates appetite and food intake. - It plays a crucial role in regulating energy balance and is increased during fasting states. *Agouti related peptide* - **Agouti-related peptide (AgRP)** is a strong **orexigenic peptide** that increases food intake. - It acts as an **antagonist** at the MC3R and MC4R melanocortin receptors, counteracting the appetite-suppressing effects of α-MSH. *Melanocyte concentrating hormone* - **Melanin-concentrating hormone (MCH)** is an **orexigenic neuropeptide** that stimulates feeding behavior. - It is primarily expressed in the lateral hypothalamus and plays a significant role in promoting appetite and weight gain.
Question 8: Which of the following is false about bipolar disorder?
- A. Unipolar mania is more common than bipolar disorder (Correct Answer)
- B. Genetic factors play important role
- C. Rapid cycling is more common in females
- D. Age of onset is earlier than unipolar depression
Explanation: ***Unipolar mania is more common than bipolar disorder*** - This statement is **false** because **unipolar mania is extremely rare**, while **bipolar disorder (which includes both manic and depressive episodes)** is significantly more common. - **Unipolar mania** refers to recurrent manic episodes without any depressive episodes, a presentation that is seldom observed clinically. *Genetic factors play important role* - This statement is **true**, as **bipolar disorder has a strong genetic component**, with **heritability estimated between 60-80%**. - **First-degree relatives** of individuals with bipolar disorder are at a significantly higher risk of developing the condition. *Rapid cycling is more common in females* - This statement is **true**; **rapid cycling (4 or more mood episodes per year)** occurs more frequently in females with bipolar disorder. - **Women with bipolar disorder** are also more likely to experience **mixed features** and **more depressive episodes** compared to males. *Age of onset is earlier than unipolar depression* - This statement is **true** because the **typical age of onset for bipolar disorder is in early adulthood (late teens to early 20s)**, whereas **unipolar depression often has a later average onset**, though both can occur at any age. - An earlier age of onset in bipolar disorder is linked to poorer prognosis and more severe illness course.
Question 9: What is the primary characteristic feature of Klein-Levin syndrome?
- A. Insomnia
- B. Anxiety
- C. Depression
- D. Hypersomnia (Correct Answer)
Explanation: ***Hypersomnia*** - **Hypersomnia** is the cardinal and primary characteristic feature of Klein-Levin syndrome, characterized by recurrent episodes of excessive sleepiness lasting days to weeks. - During these episodes, individuals may sleep for **16 to 20 hours a day** and are extremely difficult to awaken. - Episodes are often accompanied by **cognitive disturbances** (confusion, derealization), **behavioral changes** (apathy, hyperphagia, hypersexuality), but **hypersomnia remains the defining feature**. - Normal functioning returns between episodes. *Insomnia* - **Insomnia** (difficulty falling or staying asleep) is the opposite of the key symptom seen in Klein-Levin syndrome. - Klein-Levin syndrome is a disorder of excessive sleep, not sleep deprivation. *Anxiety* - **Anxiety** may occur as a secondary feature or during the distress of episodes, but it is not the primary characteristic feature. - The core pathology manifests as profound sleep disturbance, not an anxiety disorder. *Depression* - **Depression** is sometimes observed during or after episodes of Klein-Levin syndrome, but it is not the primary defining feature. - The diagnostic hallmark is the **recurrent hypersomnia with associated cognitive and behavioral symptoms**, not mood disturbance.
Question 10: A 45-year-old male's blood test shows an increase in Homovanillic acid (HVA). Which of the following conditions is this finding most likely associated with?
- A. Phenylketonuria (PKU)
- B. Schizophrenia (Correct Answer)
- C. Depression
- D. Parkinson's disease
Explanation: **Explanation:** The correct answer is **Schizophrenia**. This question tests your knowledge of neurotransmitter metabolites and their clinical significance in psychiatric disorders. **1. Why Schizophrenia is correct:** **Homovanillic acid (HVA)** is the primary metabolic byproduct of **Dopamine**. According to the **Dopamine Hypothesis of Schizophrenia**, the disorder is characterized by dopaminergic hyperactivity, particularly in the mesolimbic pathway. Increased turnover of dopamine leads to elevated levels of HVA in the blood, cerebrospinal fluid (CSF), and urine. Monitoring HVA levels is often used in research to gauge central dopamine activity. **2. Why the other options are incorrect:** * **Phenylketonuria (PKU):** This is a metabolic disorder caused by a deficiency of phenylalanine hydroxylase. It leads to an accumulation of Phenylalanine, not HVA. * **Depression:** Depression is primarily associated with decreased levels of **5-HIAA** (5-Hydroxyindoleacetic acid), which is the metabolite of Serotonin. While dopamine can be involved, HVA is not a diagnostic marker for depression. * **Parkinson’s Disease:** This condition involves the degeneration of dopaminergic neurons in the substantia nigra. Therefore, one would expect a **decrease** in HVA levels due to dopamine deficiency, rather than an increase. **High-Yield Clinical Pearls for NEET-PG:** * **Dopamine → HVA** (Homovanillic Acid) * **Serotonin → 5-HIAA** (Decreased in suicide attempts and impulsive aggression) * **Norepinephrine → VMA** (Vanillylmandelic Acid) and **MHPG** (3-methoxy-4-hydroxyphenylglycol). * **VMA** is a crucial marker for diagnosing **Pheochromocytoma** and **Neuroblastoma**. * In Schizophrenia, HVA levels often correlate with the severity of positive symptoms (hallucinations/delusions).
Want unlimited practice?
Get full access to all questions, explanations, and performance tracking.
Start For Free