10 USMLE Psychiatry Questions with Answers and Explanations (Set 1)

These 10 USMLE psychiatry and behavioral science practice questions cover topics that repeat on Step 1 and Step 2 CK: alcohol withdrawal, delirium, bulimia nervosa, antisocial personality and conduct disorder, child neglect, defense mechanisms, reactions to bad news, suicide risk and Alzheimer disease. Each question includes the correct answer and an explanation.

Written by Dr. Ray Makar, MD, author of the Repeated USMLE Questions eBook series.

Prefer video? Watch daily USMLE case questions on MedFocus by Dr. Ray on YouTube.

How to use this page: read the question, pick your answer, then tap Show Answer and Explanation.

Questions

Question 1. A 39-year-old man presents to the ER with his wife. They were watching TV when she noticed that her husband was confused and stumbling. He is not usually at home at this time but he did not feel good all day. He used to drink every night with his friends at the bar but he did not go with them in the last two nights. He assumed that he was tired because he drank too much last time two days ago. He denied chest pain, shortness of breath or any abdominal symptoms. His CT scan is negative for any mass or bleeding. His lab tests show: AST 64 U/L ALT 24 U/L Lactate dehydrogenase 267 U/L What is the most likely diagnosis of this patient’s condition?

A- Alcohol toxicity
B- Alcohol withdrawal
C- Stroke
D- Heart attack

This patient is alcoholic. He drinks every night with his friends. The signs and symptoms that he suffers now is typical of alcohol withdrawal. Alcohol withdrawal starts to show up signs after 24-36 hours after the last drink.
The correct answer is B

 

Question 2. An 82-year-old woman who underwent right knee replacement yesterday develops new symptoms. Right after surgery, she was agitated, awake all night and refused to eat or take postoperative medications. Today she is still agitated and not oriented to time and place. What is the most appropriate management at this point?

A- Restrain in bed and lorazepam administration
B- Restrain in bed and haloperidol administration
C- Sleep enhancement protocol and family support as well as haloperidol administration
D- Diphenhydramine to enhance sleeping
E- Refer to psychiatry department

This is a case of delirium. It is mild in this patient and she only needs support and normalizing sleep-wake cycle. Restraint is only recommended in cases of severe delirium to avoid hurting herself and others. Haloperidol is safe to improve agitation. Benzodiazepines enhance delirium and they are not recommended in this case. Referral to psychiatry is premature in this mild case of delirium.
The correct answer is C

 

Question 3. A 26-year-old woman is brought to the emergency room due to a 2-hour history of hematemesis. She was invited to a banquet at her work, and she vomited twice with a considerable amount of blood. Her medical, surgical, and family histories are unremarkable. She visits her dentist regularly for recurrent dental caries. She doesn’t smoke or drink alcohol. Her pulse is 100/min, blood pressure is 104/66 and her temperature is 97.8 F. Abdomen is soft, nontender without organomegaly. Her laboratory tests are as follows: Serum sodium 136 meq/L. Serum potassium 2.6 meq/L. Serum chloride 84 meq/L. Serum bicarbonate 38 meq/L. Endoscopic examination reveals erosive esophagitis without any scars or adhesions. What is the most likely diagnosis?

A- Bulimia nervosa
B- CREST syndrome
C- Mallory-Weiss syndrome
D- NSAID-induced esophagitis
E- Staphylococcal food poisoning

This is a typical presentation of bulimia nervosa suggested by history of recurrent dental caries and laboratory investigations. Bulimia is characterized by low chloride, low potassium and high bicarbonate. Mallory-Weiss is mainly related to alcohol binge. This patient does not drink alcohol.
The correct answer is A

 

Question 4. A 19-year-old college student is brought to the emergency room by a police officer because of a cut wound on his arm. The student was arrested for committing a robbery at a convenience store. His record shows two fights with his neighbors on different occasions because he used to hit their pets. He also had two incidents of shoplifting. Which is the most likely diagnosis?

A- Antisocial personality disorder
B- Borderline personality disorder
C- Conduct disorder
D- Histrionic personality disorder
E- Obsessive-compulsive disorder

This patient represents a typical case of antisocial personality disorder. The same scenario can also be a typical match for conduct disorder but if the patient is younger than 18 years of age.
Antisocial personality disorder is characterized by treating other people with pervasive disregard of their rights and respect. Patients with antisocial personality disorder commit crimes for personal gain and for their own pleasure. They have no remorse as they justify their behavior by blaming their victims for being foolish and deserve it. They also look indifferent to the harmful effects they cause to other people. It is more common in men than women and decreases by aging suggesting that bad experience could lead to a change of their way of life. Diagnosis is usually made by history and clinical criteria. Treatment includes cognitive-behavioral therapy, antipsychotics and antidepressants. Other choices have different criteria that do not match this scenario.
The correct answer is A

 

Question 5. A 7-year-old boy has a difficult time at school. He sleeps during most of the classes and doesn’t interact with his teachers in class. He is fighting with many of his classmates because of stealing their lunches but he has never started a fight. When teachers tried to contact his family, they found out that his family left a fake address and phone number. What is the most likely cause of this boy’s behavior?

A- Attention-deficit-hyperactive disorder (ADHD)
B- Antisocial personality
C- Child abuse or neglect
D- Oppositional defiant disorder (ODD)
E- Mental retardation

This boy sleeps in class because he does not sleep well at home. He also steals because he doesn’t eat or bring food from home. There is no certain abnormality in his behavior. The most likely cause of this boy’s behavior is child neglect, a form of child abuse.
The correct answer is C

 

Question 6. A 12-year old child is brought to his psychiatrist for an evaluation of abnormal behavior. His teachers contacted his parents several times because he always cheats and lies at school. He also shoots family dog with his BB gun although he gets in trouble doing that. He has no remorse on hitting other kids and has no concern about others’ feelings. Which of the following is the most likely diagnosis?

A- Schizophrenia
B- Attention-deficit hyperactivity disorder (ADHD)
C- Conduct disorder
D- Bipolar disorder

This boy has a typical presentation of conduct disorder. He enjoyed hurting animals as well as human beings. He lies constantly and has no remorse for any trouble he is causing. Most of the children with this disorder develop into antisocial personality disorder when they get older. Signs and symptoms don’t meet the criteria of other choices.
The correct answer is C

 

Question 7. During your morning round in the internal medicine department, one of the patients tells you that the nurses are insensitive and irresponsible. When you ask him why, he says: “They are not as good as the doctors. All the doctors I have seen here are sensitive and responsible.” Which of these is the most likely defense mechanism involved in this case?

A- Projection
B- Reaction formation
C- Regression
D- Repression
E- Splitting

This defense mechanism is characterized by dividing 2 groups of people into two opposite characters. Doctors are sensitive and responsible while nurses are insensitive and irresponsible. In other words, he is splitting them. Other choices have different definitions.
The correct answer is E

 

Question 8. A 43-year-old man presents to your clinic for a follow up after colon biopsy taken last week. He has a history of constipation and blood in stools for 6 months. Biopsy reveals colon cancer. After you told him the bad news, he looked down and told you that constipation was not that bad. He seeks more investigations because he does not think that he has cancer. What is the emotional stage experienced by this patient at this time?

A- Denial
B- Anger
C- Bargaining
D- Depression
E- Acceptance

The first reaction to life-threatening news is denial. Some doctors go further with more investigations to confirm the diagnosis at the patient’s request. Other stages come after and end in acceptance of the condition and following treatment.
The correct answer is A

 

Question 9. A 16-year-old high school student presents to the office with her mother for consultation. Her mother admits that her daughter is sad because she recently broke up with her friend. Yesterday, she tried to cut her wrist, but her brother screamed, and they stopped her. The girl does not make eye contact, and her head is bent down throughout the interview. She tells the doctor that she does not want to live anymore. She refuses to answer any questions and declined a physical examination. What is the most appropriate next step of management for this patient?

A- Admit to the hospital
B- Refer to the psychiatric clinic the next day
C- Refer to the social worker
D- Prescribe antidepressant and follow up in a week
E- Advise the family that it is a normal reaction, and keep an eye on her

The rule of thumb in cases of suicide attempts is hospitalization and everything else would come after that. This is a common question in all steps of USMLE and you will see this case a lot in practice. Any interaction other than admission to the hospital is considered a high liability and will lead to a lawsuit.
The correct answer is A
Key takeaway:👉 Any adolescent with suicidal ideation plus a recent attempt requires immediate hospitalization for safety.

 

Question 10. An 82-year-old man is brought to the clinic by his son who is concerned about his father’s mental status. He told you that his father has recently become more forgetful and angry. He doesn’t remember recent events and he gets frustrated when he fails to complete simple tasks. On examination, the patient is unkempt. His vital signs are within normal limits. Mini-mental status test scores 12/30. MRI of the brain shows some areas of degeneration in the temporal lobe. What is the most appropriate treatment of this condition?

A- Citalopram
B- Fluoxetine
C- Metoclopramide
D- Donepezil
E- Diazepam

This patient has dementia, most likely Alzheimer’s disease. The drug of choice is donepezil. Other choices have no role in the treatment or improvement of this patient’s mental status.
The correct answer is D

 

High-yield points from this set

  • Confusion and unsteadiness 24–72 hours after the last drink in a heavy drinker = alcohol withdrawal.
  • Post-operative fluctuating confusion in an elderly patient = delirium; avoid benzodiazepines.
  • Vomiting, dental caries and hypokalemic metabolic alkalosis = bulimia nervosa.
  • Conduct disorder before 18 years; antisocial personality disorder at 18 years or older.
  • A child sleeping in class and stealing food, with a family that cannot be reached, suggests neglect.
  • Seeing people as all good or all bad = splitting.
  • Denial is usually the first reaction to bad news.
  • A teenager who attempted suicide and still wants to die must be admitted to the hospital.
  • Memory loss with temporal lobe atrophy = Alzheimer disease; treat with donepezil.
  • Cruelty to animals, lying and no remorse in a child = conduct disorder.

Keep practicing

Leave a Comment