USMLE USMLE Certifications USMLE-STEP-3 Questions & Answers

• Question 221:

  A 6-year-old girl is brought in to the primary care clinic for evaluation by her foster parents, who are concerned that "something is wrong with her." They have noticed odd behavior, with repetitive words and phrases, and difficulty following directions. Her vital signs are normal. Her physical examination is remarkable for a head circumference greater than the 90th percentile but a height less than the 30th percentile, large-appearing ears, and significant flexibility in the joints.

  Which of the following chromosomes is most likely abnormal in this patient?

  A. 5

  B. 15

  C. 18

  D. 21

  E. X

  Correct Answer: E Section: (none)

  Explanation:

  This patient displays the classic phenotype for fragile X syndrome: a large, long head, long ears, short stature, hyperextensible joints, and macro-orchidism (in males). Cri du chat syndrome involves a deletion affecting chromosome 5 and is characterized by microcephaly, low-set ears, and severe mental retardation. Chromosome 21 is involved in Down syndrome, the most common single cause of mental retardation. Patients with Down syndrome exhibit slanted eyes, epicanthal folds, and a flat nose. Fragile X syndrome results from a mutation on the X chromosome. Fragile X syndrome is the second most common single cause of mental retardation, with affected individuals having mild-to-severe mental retardation. It is also associated with various comorbid diagnoses, including learning disorders, autism, and approximately a 75% rate of ADHD.

• Question 222:

  The patient is a 48-year-old Marine veteran who has self-referred to the emergency room. He complains of feeling "depressed" and suicidal for the past several days. He admits to using "crack" cocaine daily for the past 3 weeks, but he is vague regarding how he obtains and affords his drugs. He also drinks several 40 oz beers three to four times per week and smokes marijuana "on occasion." He has been homeless, staying with "friends" and in shelters. He last used cocaine this morning and wishes to be admitted for detoxification

  He is subsequently admitted to the mental health unit but the next day is evaluated for complaints of withdrawal symptoms. He complains of insomnia, listlessness, irritability, and worsening dysphoria.

  Which of the following would be the most appropriate treatment strategy for his current condition?

  A. antidepressant treatment

  B. benzodiazepine taper

  C. education and reassurance

  D. methadone detox

  E. phenobarbital detox

  Correct Answer: C Section: (none)

  Explanation:

  There frequently are comorbid diagnoses in individuals with cocaine dependence. Affective disorders (including bipolar and major depression) as well as anxiety disorders are not uncommonly seen in cocaine-addicted patients. Schizophrenia is not appreciably increased in this patient population. Antisocial personality disorder is the most likely associated diagnosis in patients with cocaine dependence. Antidepressant treatment may be indicated if there is a comorbid depressive illness, but it will not specifically alleviate any withdrawal symptoms. A benzodiazepine taper would be necessary if this patient were displaying significant alcohol withdrawal symptoms. A methadone detox is often used for patients who are having severe opiate withdrawal but is not appropriate for cocaine withdrawal.

  A phenobarbital detox can be used to prevent withdrawal from benzodiazepines and can also be used (less frequently) for alcohol withdrawal. Unlike alcohol, benzodiazepine, or barbiturate withdrawal, withdrawal from cocaine is not life threatening and does not require pharmacologic intervention. Education about cocaine addiction and withdrawal, as well as reassurance regarding the likely short duration of symptoms, are all that are needed.

• Question 223:

  The patient is a 48-year-old Marine veteran who has self-referred to the emergency room. He complains of feeling "depressed" and suicidal for the past several days. He admits to using "crack" cocaine daily for the past 3 weeks, but he is vague regarding how he obtains and affords his drugs. He also drinks several 40 oz beers three to four times per week and smokes marijuana "on occasion." He has been homeless, staying with "friends" and in shelters. He last used cocaine this morning and wishes to be admitted for detoxification. Which of the following is most likely to be a comorbid diagnosis in this individual?

  A. antisocial personality disorder

  B. bipolar disorder

  C. GAD

  D. major depressive disorder

  E. schizophrenia

  Correct Answer: A Section: (none)

  Explanation:

  There frequently are comorbid diagnoses in individuals with cocaine dependence. Affective disorders (including bipolar and major depression) as well as anxiety disorders are not uncommonly seen in cocaine-addicted patients. Schizophrenia is not appreciably increased in this patient population. Antisocial personality disorder is the most likely associated diagnosis in patients with cocaine dependence. Antidepressant treatment may be indicated if there is a comorbid depressive illness, but it will not specifically alleviate any withdrawal symptoms. A benzodiazepine taper would be necessary if this patient were displaying significant alcohol withdrawal symptoms. A methadone detox is often used for patients who are having severe opiate withdrawal but is not appropriate for cocaine withdrawal.

  A phenobarbital detox can be used to prevent withdrawal from benzodiazepines and can also be used (less frequently) for alcohol withdrawal. Unlike alcohol, benzodiazepine, or barbiturate withdrawal, withdrawal from cocaine is not life threatening and does not require pharmacologic intervention. Education about cocaine addiction and withdrawal, as well as reassurance regarding the likely short duration of symptoms, are all that are needed.

• Question 224:

  The patient is an 18-year-old male brought into the emergency room in the early morning by his friends after attending a dance party. He is agitated, pacing the hallway but unsteady. Despite this, he claims that he feels "wonderful" and states, "Everything will be all right." He also seems focused on seeing many colored flashes and hearing "all conversations at once." He has no known medical problems and is not taking any medication. He does admit to ingesting something early on, which he was told would help him "party all night." On physical examination, he has an elevated BP and pulse, dilated pupils, and significant diaphoresis.

  This same patient is eventually admitted for detox and successfully completes a drug treatment program. He is attending college and performing well. He returns to the urgent care clinic with complaints of reoccurring experiences similar to those he had when he was "high," such as flashing lights, intensified sounds, and halos. He is greatly upset about these and feels that they interfere with his studying. A complete physical examination and blood work (including toxicology screen) are negative.

  Administration of which of the following medications may worsen his symptoms?

  A. carbamazepine (Tegretol)

  B. clonazepam (Klonopin)

  C. fluoxetine (Prozac)

  D. haloperidol (Haldol)

  E. valproic acid (Depakene)

  Correct Answer: D Section: (none)

  Explanation:

  This patient most likely ingested MDMA (3, 4-methylenedioxymethamphetamine, ecstasy) at a rave. Cocaine likely causes its effects through blockade of dopamine reuptake, which is responsible for its reinforcing and, therefore, highly addicting nature. PCP intoxicated individuals can often be agitated, but they typically will also display nystagmus and, not infrequently, violent behavior. PCP works through blockade of glutamate receptors. Hallucinogens are thought to increase the activity of the serotonin system, and they do not necessarily cause the feeling of euphoria seen in the above case. Amphetamine intoxication, by causing the release of dopamine, can appear similar to the above case, but florid perceptual disturbances are not as frequent. Ecstasy, classically taken at raves, acts as an amphetamine and a hallucinogen, thereby creating feelings of well-being or euphoria as well as causing hallucinations.

  Its dual nature is likely due to its neurophysiologic effects of releasing both dopamine and serotonin in the brain. This patient gives a history consistent with hallucinogen persisting perception disorder (flashbacks), characterized by the reexperiencing of perceptual disturbances after cessation of use. Although there is no medication which definitively treats the flashbacks, various drugs may be helpful. These include anticonvulsants, such as carbamazepine and valproic acid, or benzodiazepines such as clonazepam. Antidepressants such as fluoxetine would be indicated if the patient displayed a depressive disorder in addition. Antipsychotics such as haloperidol are to be avoided as they have been shown to actually worsen the symptoms of flashbacks.

• Question 225:

  The patient is an 18-year-old male brought into the emergency room in the early morning by his friends after attending a dance party. He is agitated, pacing the hallway but unsteady. Despite this, he claims that he feels "wonderful" and states, "Everything will be all right." He also seems focused on seeing many colored flashes and hearing "all conversations at once." He has no known medical problems and is not taking any medication. He does admit to ingesting something early on, which he was told would help him "party all night." On physical examination, he has an elevated BP and pulse, dilated pupils, and significant diaphoresis.

  Which of the following is the most likely pharmacologic effect of the substance taken?

  A. blockade of dopamine reuptake

  B. blockade of glutamate receptors

  C. increased activity of serotonin receptors

  D. release of dopamine

  E. release of dopamine and serotonin

  Correct Answer: E Section: (none)

  Explanation:

  This patient most likely ingested MDMA (3, 4-methylenedioxymethamphetamine, ecstasy) at a rave. Cocaine likely causes its effects through blockade of dopamine reuptake, which is responsible for its reinforcing and, therefore, highly addicting nature. PCP intoxicated individuals can often be agitated, but they typically will also display nystagmus and, not infrequently, violent behavior. PCP works through blockade of glutamate receptors. Hallucinogens are thought to increase the activity of the serotonin system, and they do not necessarily cause the feeling of euphoria seen in the above case. Amphetamine intoxication, by causing the release of dopamine, can appear similar to the above case, but florid perceptual disturbances are not as frequent. Ecstasy, classically taken at raves, acts as an amphetamine and a hallucinogen, thereby creating feelings of well-being or euphoria as well as causing hallucinations. Its dual nature is likely due to its neurophysiologic effects of releasing both dopamine and serotonin in the brain. This patient gives a history consistent with hallucinogen persisting perception disorder (flashbacks), characterized by the reexperiencing of perceptual disturbances after cessation of use. Although there is no medication which definitively treats the flashbacks, various drugs may be helpful. These include anticonvulsants, such as carbamazepine and valproic acid, or benzodiazepines such as clonazepam. Antidepressants such as fluoxetine would be indicated if the patient displayed a depressive disorder in addition. Antipsychotics such as haloperidol are to be avoided as they have been shown to actually worsen the symptoms of flashbacks.

• Question 226:

  A32-year-old female presents to the outpatient clinic with complaints of ongoing headaches. For the past 8 months, she has had recurrent headaches which she describes as bilateral, occipital, with a tight/squeezing pain, lasting for several hours and relieved with nonsteroidal anti-inflammatory medication (NSAIDs). Further questioning reveals chronic feelings of fatigue and poor concentration. She admits to "constantly worrying" about her job performance as well as issues involving her relationship with a live-in boyfriend. In fact, her focusing on these concerns interferes with her sleep. As a result, she has on more than one occasion awakened with extreme panic, tremors, diaphoresis, nausea, and palpitations. Her medical problems include gastroesophageal reflux disease that is treated with famotidine. She drinks an occasional glass of wine and denies drug use.

  Which of the following medications would be the most appropriate in the long-term treatment of this patient's symptoms?

  A. alprazolam (Xanax)

  B. atenolol

  C. bupropion (Wellbutrin)

  D. lithium

  E. venlafaxine (Effexor)

  Correct Answer: E Section: (none)

  Explanation:

  The patient does not complain of significant depression, anhedonia, problems with appetite, or guilt consistent with major depressive disorder. She also does not complain of specific obsessions or compulsions necessary for OCD, such as fears of dirt, hurting individuals, or the need for symmetry. While she does have panic attacks, they are not unexpected as they relate to her worries about aspects of her life. She also does not have the ongoing fear of having more attacks characteristic of panic disorder. Social phobia consists of fears of acting in an embarrassing or humiliating way in public, which are not apparent in the above case. She complains of excessive anxiety and worry about a number of activities associated with other cognitive and physical symptoms. This case fits the criteria for GAD (DSM IV-TR). GAD tends to be chronic, often requiring lifelong treatment. Although benzodiazepines such as alprazolam are effective, they should not be prescribed indefinitely given their side effects (sedation, disinhibition) and potential for tolerance, withdrawal, and abuse.

  They are not infrequently used in conjunction with another medication, often in the short-term, until the primary psychotropic medication takes effect. Atenolol or other beta-blockers can be useful in situational anxiety, such as social phobia (social anxiety disorder) or specific phobia. Beta-blockers treat the somatic manifestations of anxiety more than the cognitive and affective components. As bupropion is thought to block the reuptake of dopamine and/or norepinephrine, it tends to cause activation and is not considered to be a first-line treatment for GAD. Lithium is a mood stabilizer that is also used in cases of refractory depression. It is inappropriate for use in the treatment of GAD. Venlafaxine, which blocks the reuptake of both serotonin and norepinephrine, and other SSRIs are effective and well tolerated in patients suffering with GAD. Their safety and efficacy make them appropriate first-line and maintenance therapies for GAD

• Question 227:

  A 68-year-old widow presents to the primary care clinic for a routine appointment. Her current medical problems include hypertension, obesity, and chronic obstructive pulmonary disease. She has no significant psychiatric history, although she saw a psychologist for eight sessions after her husband died. She does not drink alcohol or use illicit drugs. She has smoked one-and-a-half to two packs of cigarettes per day for the past 45 years and she wishes to quit. She has heard about some of the options but is unsure which would be the most effective.

  After being informed of the various choices, she decides to proceed with medication. Which of the following medications is most useful for tobacco cessation?

  A. bupropion (Wellbutrin)

  B. fluoxetine (Prozac)

  C. mirtazepine (Remeron)

  D. trazodone (Desyrel)

  E. venlafaxine (Effexor)

  Correct Answer: A Section: (none)

  Explanation:

  The quit rates for abrupt cessation and education/advice are quite low when used alone. The rates increase significantly with behavioral interventions or the use of medications such as nicotine replacement. The highest quit rates are likely seen with the combination of medications plus behavioral therapy such as group therapy. (Synopsis, p. 446) The reinforcing aspects of nicotine addiction are thought to involve the dopaminergic system in the central nervous system. This may be one reason why bupropion, which likely increases dopamine activity, is very effective in helping patients to quit smoking. The other antidepressants listed have not demonstrated efficacy for nicotine dependence.

• Question 228:

  A32-year-old female presents to the outpatient clinic with complaints of ongoing headaches. For the past 8 months, she has had recurrent headaches which she describes as bilateral, occipital, with a tight/squeezing pain, lasting for several hours and relieved with nonsteroidal anti-inflammatory medication (NSAIDs). Further questioning reveals chronic feelings of fatigue and poor concentration. She admits to "constantly worrying" about her job performance as well as issues involving her relationship with a live-in boyfriend. In fact, her focusing on these concerns interferes with her sleep. As a result, she has on more than one occasion awakened with extreme panic, tremors, diaphoresis, nausea, and palpitations. Her medical problems include gastroesophageal reflux disease that is treated with famotidine. She drinks an occasional glass of wine and denies drug use. Which of the following is her most likely diagnosis?

  A. GAD

  B. major depressive disorder

  C. OCD

  D. panic disorder

  E. social phobia

  Correct Answer: A Section: (none)

  Explanation:

  The patient does not complain of significant depression, anhedonia, problems with appetite, or guilt consistent with major depressive disorder. She also does not complain of specific obsessions or compulsions necessary for OCD, such as fears of dirt, hurting individuals, or the need for symmetry. While she does have panic attacks, they are not unexpected as they relate to her worries about aspects of her life. She also does not have the ongoing fear of having more attacks characteristic of panic disorder. Social phobia consists of fears of acting in an embarrassing or humiliating way in public, which are not apparent in the above case. She complains of excessive anxiety and worry about a number of activities associated with other cognitive and physical symptoms. This case fits the criteria for GAD (DSM IV-TR). GAD tends to be chronic, often requiring lifelong treatment. Although benzodiazepines such as alprazolam are effective, they should not be prescribed indefinitely given their side effects (sedation, disinhibition) and potential for tolerance, withdrawal, and abuse.

  They are not infrequently used in conjunction with another medication, often in the short-term, until the primary psychotropic medication takes effect. Atenolol or other beta-blockers can be useful in situational anxiety, such as social phobia (social anxiety disorder) or specific phobia. Beta-blockers treat the somatic manifestations of anxiety more than the cognitive and affective components. As bupropion is thought to block the reuptake of dopamine and/or norepinephrine, it tends to cause activation and is not considered to be a first-line treatment for GAD. Lithium is a mood stabilizer that is also used in cases of refractory depression. It is inappropriate for use in the treatment of GAD. Venlafaxine, which blocks the reuptake of both serotonin and norepinephrine, and other SSRIs are effective and well tolerated in patients suffering with GAD. Their safety and efficacy make them appropriate first-line and maintenance therapies for GAD.

• Question 229:

  A 55-year-old woman with recurrent major depressive episodes presents for medical clearance prior to receiving electroconvulsive therapy (ECT) as she is deemed to be treatment refractory. She complains of pervasive depressive feelings and neurovegetative symptoms as well as suicidal ideation. She denies any physical complaints but is taking felodipine 5 mg daily for her hypertension, which has been well-controlled. Despite receiving a detailed explanation of the procedure, she remains "nervous" about receiving ECT and its potential complications. What should she be told is the most likely side effect from ECT?

  A. broken teeth

  B. fractures

  C. hypertension

  D. memory loss

  E. vomiting

  Correct Answer: D Section: (none)

  Explanation:

  ECT is considered a very safe procedure overall. The mortality rate is comparable to general anesthesia and childbirth. Unlike in years past, the routine use of muscle relaxants makes broken teeth and fractures unlikely. ECT should not raise BP appreciably in a patient with controlled hypertension. Nausea and vomiting are uncommon and can be minimized with antiemetics given during the ECT sessions. By far, the most common side effect is memory loss, which almost always resolves.

• Question 230:

  A 68-year-old widow presents to the primary care clinic for a routine appointment. Her current medical problems include hypertension, obesity, and chronic obstructive pulmonary disease. She has no significant psychiatric history, although she saw a psychologist for eight sessions after her husband died. She does not drink alcohol or use illicit drugs. She has smoked one-and-a-half to two packs of cigarettes per day for the past 45 years and she wishes to quit. She has heard about some of the options but is unsure which would be the most effective.

  Which of the following strategies is most likely to succeed in helping her to quit smoking?

  A. abrupt cessation

  B. behavior therapy

  C. education

  D. medications such as nicotine replacement

  E. medications with group therapy

  Correct Answer: E Section: (none)

  Explanation:

  The quit rates for abrupt cessation and education/advice are quite low when used alone. The rates increase significantly with behavioral interventions or the use of medications such as nicotine replacement. The highest quit rates are likely seen with the combination of medications plus behavioral therapy such as group therapy. (Synopsis, p. 446) The reinforcing aspects of nicotine addiction are thought to involve the dopaminergic system in the central nervous system. This may be one reason why bupropion, which likely increases dopamine activity, is very effective in helping patients to quit smoking. The other antidepressants listed have not demonstrated efficacy for nicotine dependence.