MSN 671 : Psychopathopharmacology I -Module 4 quiz 4

Correct Answer:

D. Stroop Task

Explanation:

The Stroop Task is a classic neuropsychological test used to assess selective attention, cognitive flexibility, and inhibitory control. In this task, individuals must name the color of the ink in which a word is printed, rather than reading the word itself. This creates a conflict between automatic word reading and controlled processing, making it a sensitive measure of executive dysfunction commonly observed in ADHD.

Why Other Options Are Wrong:

A. NICHQ Vanderbilt Assessment Scale

This is incorrect because the Vanderbilt scale is a behavioral rating tool completed by parents and teachers, not a direct neuropsychological test.

B. Wender Utah Rating Scale for ADHD

This is incorrect because the Wender Utah Rating Scale is a retrospective self-report questionnaire used to assess ADHD symptoms that began in childhood.

C. ADHD Rating Scale

This is incorrect because the ADHD Rating Scale is a symptom checklist aligned with DSM criteria, not a cognitive performance task.

Correct Answer:

A. Dopamine and norepinephrine

Explanation:

The prefrontal cortex is responsible for executive functions such as attention, working memory, and impulse control. In ADHD, impaired regulation of dopamine and norepinephrine in prefrontal circuits leads to inefficient tuning of information processing. Stimulant medications like methylphenidate and amphetamines improve ADHD symptoms by enhancing both dopamine and norepinephrine signaling in these pathways.

Why Other Options Are Wrong:

B. Dopamine and serotonin

This is incorrect because serotonin primarily modulates mood, sleep, and anxiety, not the executive dysfunction central to ADHD.

C. Norepinephrine and serotonin

This is incorrect because serotonin is not a primary regulator of prefrontal attention circuits. Norepinephrine contributes, but dopamine is equally essential.

D. Dopamine and glutamate

This is incorrect because while glutamate is the brain’s main excitatory neurotransmitter, it is dopamine and norepinephrine specifically that fine-tune prefrontal cortical function in ADHD.

Correct Answer:

B. Stroop Task

Explanation:

The Stroop Task is a neuropsychological test that measures selective attention, inhibitory control, and cognitive flexibility. In this task, a person must state the ink color of a word (e.g., the word “blue” written in red ink) instead of reading the word itself. This creates a conflict between automatic reading and controlled processing, making it especially useful for detecting executive dysfunction, as seen in ADHD.

Why Other Options Are Wrong:

A. ADHD Rating Scale

This is incorrect because it is a symptom checklist based on DSM criteria, not a performance-based test of attention.

C. Vanderbilt Assessment Scale

This is incorrect because it is a behavioral rating scale filled out by parents or teachers, not a neurocognitive attention test.

D. Wender Utah Rating Scale

This is incorrect because it is a retrospective self-report questionnaire for adults recalling ADHD symptoms from childhood, not a selective attention task.

Correct Answer:

C. Citalopram

Explanation:

Among SSRIs, citalopram is most strongly associated with QT interval prolongation, especially at higher doses (>40 mg/day). This increases the risk of torsades de pointes and sudden cardiac death. Because of this risk, the FDA has issued dosing limits and recommends EKG monitoring in patients with cardiac risk factors.

Why Other Options Are Wrong:

A. Paroxetine

This is incorrect because paroxetine is not associated with significant QT prolongation; its main concerns are weight gain and withdrawal symptoms.

B. Fluoxetine

This is incorrect because fluoxetine has a long half-life and drug–drug interactions but is not strongly linked to QT prolongation.

D. Fluvoxamine

This is incorrect because fluvoxamine is more associated with drug interactions due to CYP inhibition, not QT interval prolongation.

Correct Answer:

C. Mesocortical and Mesolimbic pathways

Explanation:

Positive and negative symptoms of schizophrenia are explained by dysfunction in two major dopamine pathways. Hyperactivity in the mesolimbic pathway (increased dopamine signaling to the nucleus accumbens) produces positive symptoms such as hallucinations and delusions. Hypoactivity in the mesocortical pathway (reduced dopamine to the prefrontal cortex) contributes to negative symptoms like apathy, reduced motivation, and impaired cognition. These two pathways together form the core of the dopamine hypothesis of schizophrenia.

Why Other Options Are Wrong:

A. Mesolimbic and Nigrostriatal pathways

This is incorrect because the nigrostriatal pathway is involved in movement regulation, and its dysfunction causes extrapyramidal side effects, not schizophrenia’s positive or negative symptoms.

B. Nigrostriatal and Tuberoinfundibular pathways

This is incorrect because these two pathways are not linked to schizophrenia symptoms. The nigrostriatal pathway governs motor control, while the tuberoinfundibular pathway regulates prolactin release.

D. Tuberoinfundibular and Mesocortical pathways

This is incorrect because the tuberoinfundibular pathway is not related to psychotic symptoms. Only the mesocortical pathway among these is relevant, as it contributes to negative and cognitive symptoms.

Correct Answer:

C. Clozapine

Explanation:

Clozapine is the antipsychotic most strongly associated with agranulocytosis, a potentially life-threatening drop in white blood cells (neutropenia). Because of this risk, patients must undergo regular CBC (complete blood count) monitoring. Despite this, clozapine is highly effective for treatment-resistant schizophrenia and reduces the risk of suicide in psychotic patients.

Why Other Options Are Wrong:

A. Olanzapine

This is incorrect because olanzapine can cause weight gain, sedation, and metabolic syndrome, but it is not linked to agranulocytosis.

B. Risperidone

This is incorrect because risperidone commonly causes hyperprolactinemia and EPS at higher doses but not agranulocytosis.

D. Aripiprazole

This is incorrect because aripiprazole is a partial D2 agonist with fewer metabolic and EPS risks, and it is not associated with agranulocytosis.

Correct Answer:

B. Hyponatremia

Explanation:

Lithium is handled by the kidneys in a manner similar to sodium. When sodium levels are low (hyponatremia), the kidneys reabsorb more lithium in place of sodium, which leads to elevated lithium concentrations and an increased risk of toxicity. Symptoms include tremor, ataxia, confusion, and in severe cases, seizures or coma.

Why Other Options Are Wrong:

A. Hypercalcemia

This is incorrect because lithium can actually cause hypercalcemia by increasing parathyroid hormone levels, but hypercalcemia itself does not increase lithium toxicity risk.

C. Hypokalemia

This is incorrect because potassium levels do not directly affect lithium clearance or toxicity.

D. Hypermagnesemia

This is incorrect because magnesium levels are not a major factor in lithium metabolism or toxicity risk.

Correct Answer:

B. 5HT2A receptor

Explanation:

Classical hallucinogens such as LSD, psilocybin, and mescaline exert their effects primarily through agonism at the serotonin 5HT2A receptor. This receptor is abundant in the cerebral cortex, where its overstimulation alters sensory perception, cognition, and mood, leading to hallucinations and psychotic-like experiences.

Why Other Options Are Wrong:

A. D2 receptor

This is incorrect because D2 receptor hyperactivity is implicated in schizophrenia’s positive symptoms, but it is not the primary mechanism of LSD’s hallucinogenic effects.

C. GABA-A receptor

This is incorrect because GABA-A receptors mediate inhibitory neurotransmission and are the target of benzodiazepines and alcohol, not hallucinogens.

D. 5HT1A receptor

This is incorrect because 5HT1A receptors are involved in anxiety and mood regulation (and targeted by buspirone), but they do not mediate the hallucinogenic effects of LSD.

Correct Answer:

B. Neuroleptic malignant syndrome

Explanation:

Neuroleptic malignant syndrome (NMS) is a rare but life-threatening reaction to antipsychotics such as risperidone. It is characterized by the classic tetrad of severe muscle rigidity, hyperthermia (fever), autonomic instability, and altered mental status. It is caused by sudden, severe dopamine blockade in the central nervous system. Treatment includes immediate discontinuation of the antipsychotic, supportive care, and agents such as dantrolene or bromocriptine.

Why Other Options Are Wrong:

A. Tardive dyskinesia

This is incorrect because tardive dyskinesia involves chronic, involuntary movements (lip smacking, tongue protrusion) after long-term antipsychotic use, not fever and autonomic instability.

C. Serotonin syndrome

This is incorrect because serotonin syndrome presents with hyperreflexia, clonus, tremor, and GI symptoms, usually after serotonergic drug use. Muscle rigidity and “lead-pipe” stiffness are more characteristic of NMS.

D. Acute dystonia

This is incorrect because acute dystonia occurs within hours to days of starting an antipsychotic and involves painful muscle spasms (e.g., torticollis, oculogyric crisis), but it does not include fever or altered mental status.