Neurobiology and Genetics of Mental Disorders Practice Questions

Q: Insane paresis is associated with -

Syphilis. ***Syphilis*** - **General paresis**, or "insane paresis," is a neuropsychiatric manifestation of **tertiary syphilis**, resulting from chronic meningoencephalitis. - It presents with progressive **dementia**, personality changes, delusions, and neurological deficits. *Leishmaniasis* - This parasitic disease is characterized by various forms including **cutaneous**, **mucocutaneous**, and **visceral leishmaniasis** (kala-azar). - It typically causes skin lesions, mucocutaneous destruction, or systemic symptoms like fever, hepatosplenomegaly, and pancytopenia, but not general paresis. *Yellow fever* - **Yellow fever** is a viral hemorrhagic disease transmitted by mosquitoes, primarily affecting the liver and kidneys. - Symptoms include fever, jaundice, hemorrhage, and shock, but not the neurological degeneration seen in general paresis. *Neisseria meningitidis* - This bacterium causes **meningococcal meningitis** and **meningococcemia**, which are acute and severe infectious diseases. - While it can lead to acute neurological symptoms due to meningitis, it does not cause the chronic, progressive neuropsychiatric syndrome known as general paresis.

Q: A reduction in the CSF 5-HIAA (Hydroxyindoleacetic Acid) is associated with all the following, EXCEPT:

OCD. ***OCD*** - **Obsessive-Compulsive Disorder (OCD)** has been linked to *increased* serotonin activity or hypersensitivity, rather than reduced 5-HIAA. - A *reduction* in CSF 5-HIAA is typically associated with conditions linked to *decreased* serotonin function. *Depression* - **Reduced CSF 5-HIAA** is consistently observed in many forms of **depression**, consistent with the serotonin hypothesis of mood disorders. - Decreased serotonin metabolites suggest lower serotonin turnover or activity in the central nervous system. *Suicide* - Low CSF 5-HIAA levels are a well-established biological marker associated with an **increased risk of suicide** and suicidal behavior, regardless of diagnosis. - This finding points to impaired serotonin function contributing to impulsivity and aggression often seen in suicide attempts. *Violence* - **Aggressive and violent behaviors**, particularly impulsive aggression, have been correlated with **reduced CSF 5-HIAA** levels. - This suggests a role for dysfunctional serotonin pathways in regulating inhibitions and behavioral control.

Q: Hyperphagia, weight gain and hypersexuality is seen in ?

Kluver-Bucy syndrome. ***Kluver-Bucy syndrome*** - This syndrome is characterized by **docility**, **hypersexuality**, **hyperphagia**, and **oral tendencies**, which all align with the symptoms described. - It results from bilateral lesions of the **amygdala** and **temporal lobes**, often due to trauma, stroke, or herpes simplex encephalitis. - **Weight gain** occurs secondary to hyperphagia. *Stein-Leventhal syndrome* - Refers to **polycystic ovary syndrome (PCOS)**, which presents with reproductive and endocrine symptoms like **amenorrhea**, **hirsutism**, and **infertility**. - It does not typically involve the cluster of behavioral symptoms such as hyperphagia or hypersexuality. *Bulimia nervosa* - An eating disorder characterized by recurrent episodes of **binge eating followed by compensatory behaviors** like purging, excessive exercise, or fasting. - While it involves hyperphagia, it does not include hypersexuality or the neurological basis seen in Kluver-Bucy syndrome. *Kleine-Levin syndrome* - A rare disorder characterized by **recurrent episodes of hypersomnia**, **hyperphagia**, and **hypersexuality** in adolescent males. - Unlike Kluver-Bucy syndrome, it presents in **episodic cycles** (lasting days to weeks) with normal behavior between episodes, and does not result from structural brain lesions.

Q: Behavioural problems caused by senility, drug damage, brain injury or disease, and the toxic effects of poisons are classified as __________ disorders

Organic. ***Organic*** - **Organic disorders** are characterized by behavioral or psychological symptoms that are directly attributable to a **physiological dysfunction** or structural change in the brain. - This category includes conditions arising from **senility**, drug-induced damage, brain injury, disease (e.g., **dementia**), or exposure to **neurotoxins**. *Psychosomatic* - **Psychosomatic disorders** involve physical symptoms that are caused or aggravated by **psychological factors**, like stress. - The primary cause is not a direct physiological injury or disease of the brain itself. *Substance use* - **Substance use disorders** describe maladaptive patterns of substance use leading to clinically significant impairment or distress. - While drug damage is mentioned in the question, this category focuses specifically on the **addiction** and related behaviors, not the broad range of organic causes. *Psychotic* - **Psychotic disorders** are characterized by a significant loss of contact with reality, often involving **hallucinations** or **delusions**. - While some organic conditions can cause psychotic symptoms, the term "psychotic disorders" refers to a specific symptom cluster rather than the underlying physical cause.

Q: Which neurotransmitter deficit is MOST consistently implicated as the primary mechanism in the pathophysiology of depression?

Serotonin. ***Serotonin (decreased levels)*** - The **monoamine hypothesis** of depression suggests that a functional deficit of neurotransmitters is central to its pathophysiology, with **serotonin (5-HT) most consistently highlighted as the primary driver**. - Reduced levels of serotonin in the synaptic cleft lead to impaired neurotransmission, affecting **mood**, **sleep**, **appetite**, and **cognitive functions**. - Most **selective serotonergic antidepressants (SSRIs)** target this pathway as first-line treatment, underscoring serotonin's central role. *Norepinephrine (decreased levels)* - **Norepinephrine** is another monoamine neurotransmitter implicated in depression, and its deficiency contributes to depressive symptoms. - Low norepinephrine levels are linked to symptoms like **fatigue**, **difficulty concentrating**, and **anhedonia**. - However, while important, **decreased serotonin is more consistently emphasized as the primary pathophysiological mechanism** in most contemporary models of depression. *GABA (reduced levels)* - **GABA (gamma-aminobutyric acid)** is the primary inhibitory neurotransmitter in the brain; reduced levels are associated more strongly with **anxiety disorders** and seizure disorders. - While GABAergic system dysfunction can contribute to certain depressive symptoms, it is not considered a primary mechanism for the core pathophysiology of depression. *Dopamine (increased levels)* - **Increased dopamine levels** are more commonly associated with conditions like **schizophrenia** (mesolimbic pathway) and **mania**, not depression. - Conversely, **decreased** dopamine levels (particularly in the mesocortical pathway) are linked to anhedonia and lack of motivation in depression, making this option factually incorrect.

Q: A patient describes seeing colors when hearing certain sounds. This experience is best described as:

Synesthesia. ***Synesthesia*** - **Synesthesia** is a neurological phenomenon where stimulation of one sensory or cognitive pathway leads to automatic, involuntary experiences in a second sensory or cognitive pathway. - In this case, hearing sounds (auditory stimulation) triggers the perception of colors (visual experience), which is a classic example of **audiovisual synesthesia**. *Perceptual distortion* - **Perceptual distortion** refers to an altered perception of real external stimuli, such as **macropsia** (objects appearing larger) or **micropsia** (objects appearing smaller). - This option does not accurately describe the cross-modal nature of the patient's experience, where one sense triggers another unrelated sensory input. *Psychosis* - **Psychosis** is a severe mental disorder in which thought and emotions are so impaired that contact is lost with external reality, often involving **hallucinations** or **delusions**. - Synesthesia is a consistent, involuntary, and often pleasant or neutral experience, not indicative of a loss of touch with reality or psychiatric illness. *Sensory misperception* - **Sensory misperception** is a broad term that could encompass various errors in interpreting sensory input, but it doesn't specifically capture the unique cross-modal aspect described. - While synesthesia technically involves a form of "misperception" in a neurological sense, the term **synesthesia** is far more precise and accurate for this specific phenomenon.

Q: A patient with chronic depression and a strong family history is likely to have an imbalance in which neurotransmitter?

Decreased Serotonin. ***Decreased Serotonin*** - Chronic depression is strongly associated with a **dysregulation of serotonin** (5-HT) pathways in the brain. Many antidepressant medications (SSRIs) work by increasing serotonin availability. - A strong **family history** suggests a genetic predisposition to these neurotransmitter imbalances, with serotonin pathways being a common target for such vulnerabilities in mood disorders. *Increased Dopamine* - While dopamine is involved in mood regulation, **increased dopamine** is more commonly linked to conditions like psychosis or mania, not typically chronic depression. - Low dopamine levels can be associated with anhedonia and lack of motivation, but a primary increase is usually not implicated in depression. *Increased Norepinephrine* - **Increased norepinephrine** is often associated with anxiety, panic attacks, or manic states, rather than chronic depression. - Although norepinephrine plays a role in mood, a primary increase is not considered the core imbalance in typical depression. *Decreased GABA* - **Decreased GABA** (gamma-aminobutyric acid) is primarily linked to anxiety disorders and seizure disorders, due to its role as the brain's main inhibitory neurotransmitter. - While GABAergic system dysfunction can contribute to emotional dysregulation, it's not considered the primary neurotransmitter imbalance in chronic depression.

Q: Which receptors are primarily implicated in the pathophysiology of schizophrenia?

Dopamine D2. ***Dopamine D2*** - The **dopamine hypothesis of schizophrenia** posits that excess dopamine activity, particularly at **D2 receptors in the mesolimbic pathway**, contributes to positive symptoms (hallucinations and delusions). - Most typical and many atypical **antipsychotics** exert their primary therapeutic effects by **blocking D2 receptors**. - This is the **most established and clinically validated** mechanism in schizophrenia pathophysiology. *GABA_A* - While GABAergic dysfunction is implicated in some psychiatric disorders, **GABA_A receptors are not the primary receptors** in the core pathophysiology of schizophrenia. - Dysregulation of GABAergic interneurons may contribute to cognitive deficits, but it's not the central mechanism for hallmark symptoms. *NMDA* - **NMDA receptors** (a type of glutamate receptor) are implicated in pathophysiology, particularly regarding cognitive and negative symptoms, as **hypofunction** of these receptors contributes to glutamatergic dysfunction. - However, the **NMDA hypothesis is secondary** to the dopamine hypothesis, and D2 receptor overactivity remains the most widely accepted primary mechanism for positive symptoms. *5-HT2A* - **Serotonin 5-HT2A receptors** are significant targets for **atypical antipsychotics**, but they are **not the primary receptors** in the fundamental pathophysiology of schizophrenia. - Blockade of 5-HT2A receptors, combined with D2 blockade, helps ameliorate positive and negative symptoms and may reduce extrapyramidal side effects.

Q: Which of the following is a characteristic symptom of frontal lobe syndrome?

Indifference. ***Indifference*** - **Indifference (apathy)** is one of the most **characteristic and consistent** symptoms of **frontal lobe syndrome**, particularly with **dorsolateral prefrontal cortex** damage. - Patients exhibit **reduced spontaneous activity**, **flat affect**, lack of concern for consequences, and **decreased motivation**. - This symptom is part of the classic **frontal lobe triad**: apathy, disinhibition, and executive dysfunction. *Euphoria* - While **euphoria** and inappropriate jocularity (moria) can occur with **orbitofrontal cortex** damage, it represents only one subtype of frontal lobe syndrome presentation. - More commonly associated with **mania** in primary mood disorders or substance-induced states. - Less consistent and characteristic compared to apathy/indifference. *Irritability* - **Irritability** can occur with frontal lobe dysfunction due to impaired emotional regulation, but it is **less specific** and seen in many other psychiatric and neurological conditions. - Often secondary to frustration from cognitive difficulties rather than a primary frontal lobe symptom. - Not as pathognomonic as apathy for frontal lobe syndrome. *None of the options* - Incorrect because **indifference (apathy)** is a well-established, characteristic symptom of **frontal lobe syndrome**. - The frontal lobes, especially the **dorsolateral** and **orbitofrontal** regions, are crucial for emotional regulation, executive functions, and motivated behavior.

Question 1

Insane paresis is associated with -

Accepted Answer

Syphilis

Answer

Leishmaniasis

Answer

Yellow fever

Answer

Neisseria meningitidis

Question 2

A reduction in the CSF 5-HIAA (Hydroxyindoleacetic Acid) is associated with all the following, EXCEPT:

Accepted Answer

OCD

Answer

Depression

Answer

Suicide

Answer

Violence

Question 3

Hyperphagia, weight gain and hypersexuality is seen in ?

Accepted Answer

Kluver-Bucy syndrome

Answer

Stein-Leventhal syndrome

Answer

Bulimia nervosa

Answer

Kleine-Levin syndrome

Question 4

Behavioural problems caused by senility, drug damage, brain injury or disease, and the toxic effects of poisons are classified as __________ disorders

Accepted Answer

Organic

Answer

Psychosomatic

Answer

Substance use

Answer

Psychotic

Question 5

Which neurotransmitter deficit is MOST consistently implicated as the primary mechanism in the pathophysiology of depression?

Accepted Answer

Serotonin

Answer

Norepinephrine

Answer

GABA

Answer

Dopamine

Question 6

In schizophrenia, what role does dopamine play in the mesolimbic pathway?

Accepted Answer

It is increased, leading to positive symptoms in schizophrenia.

Answer

It is decreased, leading to negative symptoms in schizophrenia.

Answer

It is stable, contributing to cognitive symptoms in schizophrenia.

Answer

It is decreased, contributing to mood symptoms in schizophrenia.

Question 7

A patient describes seeing colors when hearing certain sounds. This experience is best described as:

Accepted Answer

Synesthesia

Answer

Perceptual distortion

Answer

Psychosis

Answer

Sensory misperception

Question 8

A patient with chronic depression and a strong family history is likely to have an imbalance in which neurotransmitter?

Accepted Answer

Decreased Serotonin

Answer

Increased Dopamine

Answer

Increased Norepinephrine

Answer

Decreased GABA

Question 9

Which receptors are primarily implicated in the pathophysiology of schizophrenia?

Accepted Answer

Dopamine D2

Answer

NMDA

Answer

GABA_A

Answer

5-HT2A

Question 10

Which of the following is a characteristic symptom of frontal lobe syndrome?

Accepted Answer

Indifference

Answer

Irritability

Answer

Euphoria

Answer

None of the options

Neurobiology and Genetics of Mental Disorders — MCQs

Neurobiology and Genetics of Mental Disorders — MCQs

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