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USMLE Step 1 High‐Yield Psychiatry Topics
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Psychiatry
High Yield USMLE Step 1 Notes
Welcome to the Psychiatry High-Yield Notes for Step 1.
These are the most commonly tested topics on the exam—ideal for quick review in your last 2 weeks before the exam, when you’re short on time, or when you’re just starting out and want to focus on what is high yield. Created and peer-reviewed by physicians who scored 260+ on Step 1 in a Q&A style to reinforce active learning.
How to use this file
- Read the question ➔ cover the answer ➔ self-quiz before revealing.
- Review the NOTES ➔ they include high-yield details you don’t want to miss.
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Table of Contents
Pediatric Disorders
1. A 6-month-old infant is brought in with lethargy and seizures. Physical exam reveals bilateral retinal hemorrhages and posterior rib fractures. What is the most likely cause?
➔ Physical child abuse (retinal hemorrhages + multiple posterior rib fractures + Subdural hematomas → think Shaken baby syndrome → indicating Physical child abuse)
- Note: Other signs of physical child abuse include:
→ Nonaccidental trauma (e.g., fractures, bruises, burns)
→ Injuries in different healing stages
→ Trauma is more severe than the scenario described by the parent - In case of suspected child abuse → notify child protective services (commonly tested)
2. A 9-year-old boy has difficulty concentrating in class and often leaves his seat. His parents also report that he is very active and disruptive at home. What is the diagnosis?
➔ Attention-Deficit Hyperactivity Disorder (Onset <12 yrs + inattention & hyperactivity in ≥2 settings → think ADHD)
- Note: Treatment:
→ First line is stimulants (methylphenidate)
→ Alternatives include atomoxetine and α₂-agonists (guanfacine) → They can be used when there is a risk of substance use or if parents prefer to avoid stimulants. - In the USMLE, to show you that the child is hyperactive in 2 settings, they mention that the school teacher complains of academic performance and hyperactivity.
3. A 3-year-old girl avoids eye contact, does not respond to her name, and spends hours spinning a toy car’s wheels. What is the diagnosis?
➔ Autism Spectrum Disorder (Impaired social interaction + repetitive behaviors + restricted interests → think Autism Spectrum Disorder)
- Note: It is more common in males and can be diagnosed even in 2-year-old kids.
- It is associated with ↑ head/brain size.
4. A 16-year-old male has a long-standing history of fighting, vandalism, and theft. He shows no remorse for his actions. What is the diagnosis?
➔ Conduct Disorder (persistent pattern of violating social norms or the rights of others without remorse → think Conduct Disorder)
- Note: Property destruction is a key for → conduct disorder
- Treatment: Cognitive behavioral therapy.
- If it persists after 18 → It is called antisocial personality disorder.
5. An 8-year-old boy often argues with teachers, deliberately refuses to follow instructions, and is spiteful toward authority figures. What is the diagnosis?
➔ Oppositional Defiant Disorder (angry/irritable mood + argumentative/defiant behavior toward authority → think Oppositional Defiant Disorder)
- Note: Treatment: Cognitive behavioral therapy.
- Unlike Conduct Disorder, Oppositional Defiant Disorder does not involve aggression toward people or animals, destruction of property, or serious violation of rules.
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6. A 7-year-old girl speaks comfortably at home but refuses to speak at school, despite understanding and being able to speak. This has been ongoing for over a month. What is the diagnosis?
➔ Selective Mutism (consistent failure to speak in specific social settings despite speaking in others for ≥1 month → think Selective Mutism)
- Note: A kid stops speaking after moving to a new school → think Selective Mutism (common scenario)
- It is an Anxiety disorder.
- Treatment: Behavioral therapy (first line)
- Differentiate from:
→ Autism Spectrum Disorder: Delayed language development, social communication deficits in all settings (not situation-specific).
→ Social Anxiety Disorder: Fear of social scrutiny, but speech is not selectively absent — they may speak with effort or distress.
7. A 10-year-old boy presents with a history of repetitive throat clearing and blinking for the past 18 months. His symptoms are worse during times of stress and are partially suppressible. What is the diagnosis?
➔ Tourette Syndrome (Stereotyped motor and vocal tics lasting >1 year (e.g., blinking + throat clearing) → think Tourette Syndrome.)
- Note: A kid who annoys the teacher by repeatedly moving his limbs (motor tic) + making noises like throat clearing (vocal tic) → classic for Tourette on the USMLE.
- Symptoms typically begin before age 18 and fluctuate in severity.
- Treatment:
→ First-line is behavioral therapy (habit reversal).
→ For severe tics, consider antipsychotics (e.g., risperidone).
8. A 6-month-old infant rolls over and has started to sit with support. What language milestones should be present at this age?
➔ Babbling
Infant Developmental Milestones (0–12 months)
| Domain | Milestones by Age |
|---|---|
| Motor | Rolls over (~4 months), Sits with support (~6 months), Stands (~10 months) |
| Social | Social smile (~2 months), Stranger anxiety (~9 months) |
| Language | Babbling (~6 months), Says “Mama”/“Dada” (~10 months) |
9. A 2-year-old boy walks, climbs stairs, and kicks a ball. What is normal social behavior at this age?
➔ Parallel play
Toddler Developmental Milestones (12–36 months)
| Domain | Milestones by Age |
|---|---|
| Motor | Walks (12 months), Climbs stairs (18 months), Kicks ball (24 months) |
| Social | Rapprochement (24 months), Parallel play (24–36 months) |
| Language | 200 words (2 years), 300 + words (3 years) |
10. A 4-year-old girl rides a tricycle and plays with other kids in a group. What language milestone is appropriate for her age?
➔ Tells simple stories
Toddler Developmental Milestones (12–36 months)
| Domain | Milestones by Age |
|---|---|
| Motor | Tricycle (3 yr), Hops (4 yr), Ties shoes (5 yr). |
| Social | Cooperative play (4 yr). |
| Language | Understand 1000 words (3 yr), Can tell detailed stories (4 yr). |
11. A child gets a sticker after behaving well in class and starts behaving better overall. What behavioral principle is being applied?
➔ Positive reinforcement (Good behavior + reward → which leads to ↑ behavior → this is Positive reinforcement)
Operant Conditioning (Skinner – Voluntary learning)
| Type | Meaning | Example |
|---|---|---|
| Positive Reinforcement | Add something good → aims to ↑ behavior | Giving a child a sticker for good behavior |
| Negative Reinforcement | Remove something bad → aims to ↑ behavior | Turning off a loud noise when seatbelt is fastened |
| Positive Punishment | Add something bad → aims to ↓ behavior | Giving detention for talking in class |
| Negative Punishment | Take away something good → aims to ↓ behavior | Taking away video games for misbehavior |
- Note: Easy Rule of Thumb:
→ Reinforcement = Increases behavior
→ Punishment = Decreases behavior
→ Positive = Add something
→ Negative = Take something away
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Psychotic disorders
12. A 25-year-old man hears voices commenting on his actions and believes others can read his thoughts. These symptoms have been present for over 7 months. What is the diagnosis?
➔ Schizophrenia
- Note: Schizophrenia: ≥6 months, requires ≥2 Symptoms (at least 1 must be from the first three points)
1. Delusions
2. Hallucinations (mostly auditory)
3. Disorganized speech
4. Disorganized/catatonic behavior
5. Negative symptoms (flat affect, anhedonia)
- Treatment: Atypical antipsychotics (e.g., risperidone).
- If you are choosing schizophrenia, make sure the symptoms are present for ≥6 months:
→ If symptoms are present for 1-6 months → think Schizophreniform Disorder.
→ If symptoms are present for less than 1 month → think Brief Psychotic Disorder.
13. A 30-year-old woman has had auditory hallucinations for 8 months. She also had a major depressive episode that lasted 2 months. The depression has resolved since a month ago, but the auditory hallucinations continue. What is the diagnosis?
➔ Schizoaffective Disorder (Psychotic symptoms (hallucinations) for ≥2 weeks in the absence of mood symptoms + history of mood episode → think Schizoaffective Disorder.)
- Note: Diagnostic clue:
→ Psychosis is present both with and without mood symptoms.
→ Schizoaffective Disorder = Schizophrenia + Mood Episode, with ≥2 weeks of psychosis occurring alone. - Make sure you can differentiate Schizoaffective from both Schizophrenia and Mood disorder with psychotic features:
→ Schizophrenia: Mood symptoms may be present but are brief and not prominent.
→ Mood disorder with psychotic features: Psychosis is only present when the mood symptoms are very severe. - USMLE Tip:
→ If psychosis persists after mood symptoms resolve → Schizoaffective
→ If psychosis only occurs during mood episodes → Mood disorder with psychotic features
Mood and Anxiety Disorders
14. A 32-year-old woman reports low energy and feelings of guilt for the past three months. She also complains of poor sleep, low appetite, and trouble concentrating. What is the diagnosis?
➔ Major Depressive Disorder (MDD)
- Note: Major depressive disorder (MDD) → ≥2 weeks of SIG E CAPS:
→ Sleep disturbance
→ Interest loss (anhedonia)
→ Guilt/worthlessness
→ Energy loss
→ Concentration difficulties
→ Appetite/weight changes
→ Psychomotor retardation/agitation
→ Suicidal ideation
- Treatment:
→ First-line: SSRIs, Cognitive Behavioral Therapy (CBT)
→ Treatment-resistant: Electroconvulsive Therapy (ECT)
15. A 40-year-old man with depression does not respond to SSRIs. He reports mood reactivity, sleeping too much, overeating, and feeling like his limbs are heavy. What type of depression does he most likely have?
➔ Atypical Depression (Mood reactivity + hypersomnia + hyperphagia + leaden paralysis (heavy limbs) → classic signs of Atypical Depression)
- Note: Leaden paralysis = limbs feel heavy (is a key feature for USMLE)
- Treatment: SSRIs, MAO inhibitors (if SSRIs fail).
16. A 28-year-old man is brought to the emergency department for extreme energy, decreased sleep, impulsive spending, and grandiosity. Since 8 days ago, he has slept only 3 hours each night, but feels energetic. What is the diagnosis?
➔ Bipolar I Disorder ( ≥1 week of manic symptoms + functional impairment → think Bipolar I Disorder)
- Note: Manic symptoms (DIG FAST):
→ Distractibility
→ Indiscretion (risky behavior: e.g., spending sprees, sex)
→ Grandiosity
→ Flight of ideas
→ Activity increase
→ Sleep need decreased
→ Talkativeness - Bipolar I Disorder:
→ Diagnosis requires ≥1 manic episode, with or without depressive episodes
→ Manic episode : ≥1 week of abnormally elevated/irritable mood + functional impairment
→ Even a single manic episode is enough to diagnose Bipolar I, regardless of depression history. - Differentiate from:
→ Bipolar II: Requires hypomania (≥4 days, no marked impairment) + at least one depressive episode
→ We need both Hypomanic and depressive episodes for the diagnosis of Bipolar II.
17. A 52-year-old woman continues to experience intense sadness, social withdrawal, and loss of daily functioning 13 months after her husband passed away. What is the most likely diagnosis?
➔ Prolonged Grief Disorder (Persistent grief lasting >12 months with functional impairment → think Prolonged Grief Disorder (also called Complicated Grief))
- Note: In the USMLE, you must be able to differentiate Normal grief from prolonged grief and MDD:
→ Normal grief: Resolves within 6 months and includes sadness, guilt, and hallucinations of the deceased.
→ Prolonged grief disorder: >12 months, persistent sadness that impairs daily life.
→ MDD is persistent, impairs functioning, and often includes feelings of worthlessness and suicidal ideation unlike Grief which is typically time-limited, with preserved self-esteem and occasional positive emotions.
18. A woman becomes tearful, anxious, and overwhelmed 3 days after giving birth. She sleeps poorly and feels emotionally labile. What is the most likely diagnosis?
➔ Postpartum Blues (Onset 2–3 days postpartum + tearfulness + emotional lability → think Postpartum Blues)
- Note: Postpartum Blues (Most common peripartum mood disorder):
→ Onset: 2–3 days post-delivery
→ Duration: Resolves within 14 days
→ Symptoms: Tearfulness, fatigue, depressed affect.
→ Treatment: Supportive, monitor for MDD.
Peripartum mood disturbances:
| Condition | Onset | Duration | Key Features |
|---|---|---|---|
| Postpartum Blues | 2–3 days | < 2 weeks | Tearful, labile mood, normal functioning |
| Postpartum Depression | Within 4 weeks | > 2 weeks | MDD criteria: anhedonia, guilt, suicidal ideation |
| Postpartum Psychosis | Days to weeks | Variable | Delusions, hallucinations, psychosis → emergency |
- Note: USMLE Tip:
→ Always screen for worsening symptoms. If symptoms persist >2 weeks or worsen, suspect Postpartum Depression.
19. A 30-year-old mother reports persistent sadness, fatigue, and disinterest in her newborn starting 3 weeks after delivery. She experiences guilt and poor concentration. What is the diagnosis?
➔ Postpartum Depression (Within 4 weeks postpartum + MDD symptoms → think Postpartum Depression)
- Note: Postpartum Depression:
→ Meets MDD criteria,
→ Onset: Within 4 weeks (can occur anytime in the first 12 months)
→ Treatment: CBT, SSRIs (first-line).
20. A 34-year-old woman hears a voice that tells her that the newborn is the devil, and she refuses to feed the child. Symptoms started within a week of delivery. What is the next best step?
➔ Hospitalization (New-onset hallucinations or delusions within days of delivery → think Postpartum Psychosis (Psychiatric emergency → Hospitalize immediately)
- Note: Postpartum Psychosis (Rare but dangerous):
→ Common scenario: Patient has a history of psychotic disorder, but stopped medication because of pregnancy.
→ Key clue: Delusions, hallucinations, thoughts of harming baby/self.
→ Treatment: Hospitalization + atypical antipsychotics, ECT if refractory.
21. A 25-year-old woman presents to the ER with palpitations and fear of dying. She has had two similar episodes in the last month and is anxious about when the next one will happen. What is the diagnosis?
➔ Panic Disorder (Recurrent, unexpected panic attacks + persistent fear of future attacks → think Panic Disorder)
- Note: Panic Disorder:
→ Symptoms: palpitations, chest pain, sweating, fear of dying, choking, and nausea that peak within 10 minutes.
→ Key clue: Ongoing worry about future attacks
→ Treatment: CBT, SSRIs; benzodiazepines for acute attacks.
| Disorder | Key Feature | Triggers | Duration | Treatment |
|---|---|---|---|---|
| Panic Disorder | Recurrent, unexpected panic attacks + persistent fear of next attack | None (attacks are spontaneous) | ≥1 month worry | CBT, SSRIs/SNRIs; benzos short-term |
| GAD | Chronic, excessive worry about multiple topics (e.g., health, work, money) | Diffuse, everyday concerns | ≥6 months | CBT, SSRIs/SNRIs |
| Specific Phobia | Intense fear of specific object/situation | Spiders, flying, heights, needles, etc. | ≥6 months | CBT with exposure therapy (first-line) |
| Social Anxiety Disorder | Fear of social embarrassment or humiliation in social or performance situations | Public speaking, social interactions | ≥6 months | CBT, SSRIs and beta-blockers (for performance only type) |
22. A 35-year-old man reports constant worry about finances and family for the past 8 months. He experiences fatigue, muscle tension, and difficulty sleeping. What is the diagnosis?
➔ Generalized Anxiety Disorder (Persistent, excessive worry about multiple domains for ≥6 months → think GAD)
- Note: GAD:
→ Symptoms (CRIMES): Concentration, Restlessness, Irritability, Muscle tension, Energy, Sleep disturbance.
→ Treatment: CBT, SSRIs, SNRIs (first-line).
23. A 22-year-old woman avoids flying due to extreme fear of crashing. The fear caused her to miss important events. What is the diagnosis?
➔ Specific Phobia (Irrational, excessive fear of a specific object or situation lasting ≥6 months → think Specific Phobia)
- Note: Treatment: Cognitive behavioral therapy with exposure to the feared object/situation.
24. A military veteran has nightmares, flashbacks, and avoids crowded areas. Symptoms began two months after returning from deployment. What is the most likely diagnosis?
➔ Post-Traumatic Stress Disorder (PTSD) (Trauma-related symptoms lasting >1 month, including re-experiencing, avoidance, mood changes, and hyperarousal → think PTSD)
- Note: Keywords: Hyperarousal + Avoidance of trauma reminders + Re-experiencing (nightmares, flashbacks) + Distress/mood changes. (HARD)
- Treatment:
→ CBT, SSRIs.
→ Prazosin for nightmares. - Note: If Symptoms <1 month → think Acute stress disorder.
25. A 19-year-old woman feels distressed by repeated intrusive thoughts about contamination and spends hours washing her hands each day. What is the diagnosis?
➔ Obsessive-Compulsive Disorder (OCD) (Intrusive obsessions causing anxiety, followed by compulsive behaviors to reduce that anxiety → think OCD)
- Note: Symptoms cause distress, time consumption, or impair function
- Treatment:
→ CBT, SSRIs (first-line)
- OCD patient is bothered by the thoughts/behaviors and wants to stop vs Obsessive Compulsive personality disorder (OCPD) patient believes their habits are helpful and sees no problem with them, e.g., “it helps me work better”)
26. A 20-year-old woman frequently checks the mirror and is preoccupied with the size of her nose, though others find it normal. He avoids social events due to this belief. What is diagnosis?
➔ Body Dysmorphic Disorder (Preoccupation with perceived defects → repetitive appearance-checking → think Body Dysmorphic Disorder)
- Note: Key feature is patient avoiding social events due to fear of looking ugly.
- Common in eating disorders.
- Treatment: CBT.
Personality Disorders
27. A 30-year-old man prefers to live alone, avoids all social contact, and shows no interest in romantic relationships. What is the diagnosis?
➔ Schizoid Personality Disorder (Persistent detachment from social relationships + limited emotional expression + no desire for intimacy → think Schizoid Personality Disorder)
- Note: In Schizoid personality (Cluster A): the patient has Social withdrawal, doesn’t want an emotional relationship VS Avoidant personality (Cluster C): the Patient wants relationships but fears rejection.
28. A 25-year-old man wears strange clothing, claims magical powers, and speaks in an odd, tangential manner. He has no close friends and lives a socially isolated life. What is the diagnosis?
➔ Schizotypal Personality Disorder (Social isolation + eccentric behavior + odd beliefs and speech patterns → think Schizotypal Personality Disorder)
- Note: Key feature is wearing weird clothes.
- Schizotypal (weird + magical thinking) vs Schizoid (emotionally flat + no magical beliefs)
29. A 19-year-old man is arrested for theft and assault. He shows no remorse and has a history of conduct disorder as a child. What is the diagnosis?
➔ Antisocial Personality Disorder( ≥18 years old + history of Conduct Disorder before age 15 + violation of others’ rights/lack of remorse → think ASPD)
- Note: If patient present with these symptoms but <18 years → think Conduct Disorder
30. A 24-year-old woman reports unstable relationships and intense fear of abandonment by her current boyfriend. She says her boyfriend is the best person in the world, but her ex-boyfriend was evil. What is the diagnosis?
➔ Borderline Personality Disorder (Emotional instability, fear of abandonment, and black-and-white thinking (known as splitting) → think Borderline Personality Disorder)
- Note: Keyword: Unstable relationships.
- Key feature is Splitting = black-and-white thinking about others (idealization vs devaluation)
- Treatment: Dialectical behavior therapy (DBT).
31. A 35-year-old woman stays in an abusive relationship because she feels helpless alone. She constantly seeks advice and reassurance from others. What is the diagnosis?
➔ Dependent Personality Disorder ((Excessive need to be taken care of → leading to submissive and clingy behavior → think Dependent Personality Disorder)
- Note: Keyword: Stuck in abusive relationship due to fear of being alone
32. A 40-year-old man is excessively focused on rules, order, and control. He insists on completing tasks “perfectly,” even if it delays work. What is the diagnosis?
➔ Obsessive-Compulsive Personality Disorder (OCPD) (Chronic pattern of perfectionism and control that interferes with flexibility → think OCPD)
- Note: Differentiate from OCD:
- OCPD: Ego-syntonic (behaviors align with self-image; patient sees them as helpful)
- OCD: Ego-dystonic (obsessions/compulsions are distressing and recognized as irrational)
33. A man is upset with his boss and later shouts at his wife over dinner. What defense mechanism is this?
➔ Displacement (Redirecting emotions to a neutral target → think Displacement
- Note: Common scenario: A Frustrated teacher shouts at his wife instead of the principal.
34. An aggressive child starts playing competitive sports and channels their energy into winning games. What defense mechanism is this?
➔ Sublimation (Aggressive impulses redirected into socially acceptable activities → think Sublimation)
- Note: Common scenarios: aggressive child → does sports.
35. A teenager angry about strict rules repeatedly breaks curfew and gets into fights instead of talking about their feelings. What is the defense mechanism?
➔ Acting out (Expressing unconscious emotional conflicts through impulsive actions rather than verbalizing feelings → think Acting out)
- Note: Common scenarios:
→ Rebellious behavior (breaking rules, fighting)
→ Skipping therapy, substance use, risky behavior after emotional stress
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Other Psychiatric Disorders
36. A middle-aged man is found wandering in another city with no memory of who he is or how he got there. What is the diagnosis?
➔ Dissociative Amnesia with Fugue (Sudden travel + inability to recall personal information → think Dissociative Amnesia with Fugue)
- Note: Key terms:
→ Dissociative Amnesia: Inability to recall important autobiographical info, usually trauma-related
→ Dissociative fugue: Dissociative Amnesia + sudden travel. - Differentiate from:
→ Dissociative Identity Disorder: Presence of ≥2 distinct identities + amnesia for daily events (often with severe childhood trauma)
37. An elderly woman with mild Alzheimer’s becomes acutely confused, disoriented, and talks to her husband, who passed away 2 years ago. What is the most likely diagnosis?
➔ Delirium (Acute onset of confusion, disorientation, and hallucinations (e.g., talking to deceased husband) in a patient with baseline dementia → think superimposed Delirium)
- Note: Most common case in USMLE is an elderly with mild dementia who developed new-onset Delirium → next step is to look for a source of acute disease (like UTI)
- Treatment: Treat underlying cause + Avoid anticholinergics, benzodiazepines, opioids.
- Delirium vs. Dementia
→ Delirium → Acute waxing/waning consciousness, disorientation, hallucinations.
→ Dementia → Chronic progressive cognitive decline, intact alertness early on.
38. A young woman develops sudden paralysis of her legs following a traumatic breakup. The neurological exam is normal, and she seems unconcerned by the symptoms. What is the diagnosis?
➔ Conversion Disorder (Psychological stressor → followed by sudden loss of motor or sensory function → think Conversion disorder)
- Note: Key feature is “La belle indifférence” (lack of concern for symptoms).
- Neurological exam is normal
39. A 30-year-old woman persistently fears that she has cancer, despite multiple normal physical exams and labs. She is frequently anxious and visits different doctors for reassurance. What is the diagnosis?
➔ Illness Anxiety Disorder (Preoccupation with having a serious illness despite reassurance → think Illness Anxiety Disorder (Hypochondriasis))
- Note: Treatment:
→ Regularly scheduled visits with the same provider
→ Address underlying anxiety (CBT is first-line) - Differentiate from:
→ Somatic Symptom Disorder: Patient has distressing somatic symptoms (vs. IAD which is fear without symptoms)
→ Conversion Disorder: Neurologic symptoms after stressor, not fear of illness
40. A 45-year-old woman is preoccupied with chronic severe abdominal pain. She frequently visits doctors despite reassurance and normal lab results. What is the diagnosis?
➔ Somatic Symptom Disorder (Excessive thoughts, anxiety, or behaviors related to ≥1 distressing physical symptom, with persistent medical help-seeking despite normal findings → think Somatic Symptom Disorder)
- Note: Symptoms are not intentionally produced (Unconscious symptoms & motivation)
- VS Malingering: Patient consciously fakes symptoms for external gain (e.g., money, avoiding work)
- VS Factitious Disorder: Patient consciously fakes symptoms to assume the sick role — for psychological gain, not external rewards
- Treat Symptom Disorders with regular follow-ups, CBT, and minimizing unnecessary tests
41. A 32-year-old nurse had blood in her urine for three months. Multiple evaluations show no sign of disease. A coworker reports seeing her mixing other patients’ blood with her urine sample. What is the diagnosis?
➔ Factitious Disorder (Imposed on Self) (Intentional symptom production for internal gain (e.g., attention, being in the patient role); no external incentives → think Factitious Disorder)
- Note: Factitious Disorder: Intentional symptoms, but unconscious motivation (internal “sick role” gain).
- Factitious Disorder Imposed on Self (Munchausen syndrome):
→ The individual deliberately produces or fakes symptoms in themselves to assume the sick role
→ leads to repeated hospital visits and unnecessary procedures. - Factitious Disorder Imposed on Another (Munchausen by proxy):
→ A caregiver intentionally causes or fabricates illness in a dependent (e.g., child or elder) to gain attention or sympathy.
→ This is considered a form of abuse. - VS If the patient had an external gain, the diagnosis would be → Malingering.
42. A 16-year-old girl has a BMI of 16, fears gaining weight, and severely restricts her food intake. She exercises excessively and reports secondary amenorrhea. What is the most likely diagnosis?
➔ Anorexia Nervosa (BMI <18.5 + intense fear of weight gain + restrictive behaviors despite being underweight → think Anorexia Nervosa)
- Note: Complications: Hypokalemia, osteoporosis, amenorrhea (↓ GnRH, ↓ LH/FSH, ↓ estrogen).
- Treatment: Nutritional rehab, psychotherapy, Olanzapine (if severe).
43. A malnourished patient with anorexia nervosa is started on nutritional therapy. Two days later, she develops weakness, arrhythmias, and seizures. Labs show ↓ phosphate, ↓ potassium, and ↓ magnesium. What is the most likely diagnosis?
➔ Refeeding Syndrome (Sudden shift to anabolism causes insulin surge, driving electrolytes (PO₄³⁻, K⁺, Mg²⁺) into cells → Refeeding Syndrome)
- Note: Leads to ↓ PO₄³⁻, ↓ K⁺, ↓ Mg²⁺ → causing arrhythmias, rhabdomyolysis, seizures.
- Prevention: Refeed slowly + monitor electrolytes closely
44. A 20-year-old college student reports recurrent binge eating episodes followed by self-induced vomiting. Her BMI is 23. On exam, she has enlarged parotid glands and calluses on her knuckles. What is the diagnosis?
➔ Bulimia Nervosa (Recurrent binge eating + compensatory behaviors (vomiting, laxatives) + normal or slightly elevated BMI → think Bulimia Nervosa)
- Note: If purging is with vomiting complications may include Metabolic alkalosis, hypokalemia, dorsal hand calluses (Russell sign), parotid hypertrophy (↑ amylase).
- Bulimia Nervosa has normal or slightly elevated BMI VS Anorexia Nervosa where the BMI is <18.5
- Treatment: CBT, SSRIs (fluoxetine).
45. A 26-year-old man reports frequent episodes of eating large amounts of food rapidly while feeling out of control. He does not purge afterward. His BMI is 30. What is the most likely diagnosis?
➔ Binge-Eating Disorder (Recurrent binge eating without compensatory behaviors + BMI > 25 → think Binge-Eating Disorder)
- Note: Most common eating disorder.
- Purging or compensatory behavior (vs Bulimia)
- Treatment: CBT (first-line), SSRIs.
46. A 6-year-old boy has episodes of screaming at night. He sits up in bed, appears terrified, but has no memory of the event the next morning. What is the most likely diagnosis?
➔ Sleep terror disorder (Child + Abrupt arousal from sleep with terror + no memory → think Sleep Terror Disorder)
- Note: Occurs during N3 (slow-wave sleep, non-REM) → so the patient has no memory of the event.
- Triggers: Fever, emotional stress, lack of sleep.
- In sleep terror disorder patients has no memory of the event VS Nightmare disorder patients remembers the dream (occurs during REM sleep)
47. A 7-year-old girl is wetting the bed at least three times a week. She has never achieved nighttime dryness. What is the first-line treatment?
➔ Behavioral modification (Child >5 yrs + never dry at night + ≥2x/week for 3 months → think Primary Enuresis → first-line treatment is behavioral strategies)
- Note: Treatment:
→ Behavioral modification (e.g. rewarding)
→ if refractory→ bedwetting alarm or desmopressin (ADH analog). - If there’s a history of overnight dryness and the patient starts wetting the bed again → this suggests secondary enuresis → Look for diseases, like urinary tract infection.
48. A 20-year-old man reports falling asleep during the day despite a full night’s sleep. He describes brief hallucinations before falling asleep and episodes of sudden muscle weakness when laughing. What is the most likely diagnosis?
➔ Narcolepsy (Daytime sleepiness + cataplexy (episodes of sudden muscle weakness when laughing) + hypnagogic hallucinations → think Narcolepsy)
- Note: It is caused by ↓ Orexin (hypocretin) in the lateral hypothalamus.
- Treatment: Scheduled naps and modafinil are first line
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Psychiatric Emergencies & Substance Use
49. A 60-year-old man with COPD says he enjoys smoking and doesn’t see a need to quit. What is the most appropriate next step in management?
➔ Ask the patient have you noticed changes in symptoms (This patient is in the precontemplation stage of behavior change → so Encourage introspection)
- Note: In behavioral change, we want to motivate patients to move on to the next step, not tackle all the steps in one visit.
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50. A 29-year-old man taking sertraline for depression and recently started on linezolid for an infection presents with confusion, high fever, sweating, and muscle twitching. On exam, he has hyperreflexia and an inducible clonus. What is the treatment?
➔ Cyproheptadine (patient taking SSRI + MAOI → leads to ↑ serotonin → leads to Serotonin Syndrome → treat with Cyproheptadine)
- Note: Serotonin syndrome (5-HT excess):
3 A’s → ↑ Activity (clonus, hyperreflexia), Autonomic instability (diaphoresis, hyperthermia), Altered mental status. - Treatment:
→ Discontinue serotonergic agents + supportive care
→ Cyproheptadine (5-HT₂ antagonist). - In serotonin syndrome there is Clonus + hyperreflexia VS In Neuroleptic malignant syndrome where there is lead pipe rigidity
51. A patient on haloperidol presents with fever, rigidity, confusion, and elevated CK. What is the diagnosis?
➔ Neuroleptic malignant syndrome (NMS) (Antipsychotic (dopamine blockade) → lead-pipe rigidity + fever + ↑ CK → think Neuroleptic Malignant Syndrome)
- Note: Classic Features: Fever, Encephalopathy ,Vitals unstable, Enzymes ↑ (especially CK), Rigidity (FEVER)
- Keyword: Lead-pipe rigidity (sustained, not velocity-dependent)
- Treatment:
→ Discontinue offending antipsychotic (mandatory)
→ Dantrolene (inhibits ryanodine receptor (RYR1)→ preventing calcium release in skeletal muscle → leading to ↓ rigidity & hyperthermia)
→ Bromocriptine (dopamine agonist).
52. A young man is started on a new antipsychotic and presents with painful muscle spasms and neck stiffness. What is the treatment?
➔ Benztropine or diphenhydramine.(Antipsychotic →lead to muscle spasms + neck stiffness + oculogyric crisis → think Acute dystonia)
- Note: Treatment: Benztropine (anticholinergic) or diphenhydramine (antihistaminic).
53. A hospitalized alcoholic begins to tremble, hallucinate, and become confused two days after admission. What is the most likely diagnosis ?
➔ Delirium tremens (Alcoholic + 2–4 days after last drink → develops tremors + hallucinations + confusion → think Delirium tremens)
- Note: A common presentation is alcoholic patient who has been hospitalized for the past 2 days
- Treated with: Benzodiazepines.
- Note: All forms of alcohol withdrawal symptoms are treated with benzodiazepines.
- Early signs of Alcohol withdrawal include tremors, Anxiety, and Insomnia
54. A patient is found unconscious with pinpoint pupils and slow respiration. What is the emergency treatment?
➔ Naloxone (Miosis + Respiratory depression + CNS depression → think Opioid overdose → treat with Naloxone)
- Note: Opioid overdose:
→ Keyword: pinpoint pupils.
→ Treatment: Naloxone (opioid antagonist).
55. A man has dilated pupils, paranoia, and says “ants are crawling” on his skin. What substance is he likely intoxicated with?
➔ Cocaine (↑ sympathetic activity + mydriasis + tactile hallucinations → think Cocaine intoxication)
- Note: Keywords for cocaine withdrawal include: Depression, hypersomnia, suicidality
- Note: Cocaine intoxication can cause chest pain, hypertension, tachycardia, and STEMI.
56. A young adult presents with red eyes, dry mouth, slowed reflexes, and excessive eating. What is the most likely substance?
➔ Cannabis (Conjunctival injection + increased appetite → think Cannabis intoxication)
57. A violent man with vertical nystagmus feels no pain and is extremely agitated. What is the most likely diagnosis?
➔ PCP intoxication (Violent behavior + ↑ pain tolerance + nystagmus (vertical) → think PCP intoxication)
- Note: Trauma is common due to violent behavior + lack of pain sensation.
| Substance | Intoxication | Withdrawal |
|---|---|---|
| Alcohol | Ataxia, slurred speech | Tremors, seizures, delirium tremens |
| Benzodiazepines | Ataxia, minor respiratory depression | Seizures, rebound anxiety |
| Opioids | Pinpoint pupils, respiratory depression | Mydriasis, yawning, flu-like symptoms |
| Cocaine | Mydriasis, paranoia, hallucinations (tactile) | Depression, hypersomnia |
| Amphetamines | Meth mites (tactile hallucinations), hyperthermia | “Crash”—depression, |
| Cannabis | Euphoria, conjunctival injection, increased appetite) | Anxiety, depression |
| LSD | Visual hallucinations, depersonalization | Flashbacks (rare) |
| MDMA (Ecstasy) | Hyperthermia, serotonin syndrome | Depression, fatigue |
| PCP | Violent behavior, nystagmus (vertical), analgesia | Agitation, anxiety, |
| Inhalants | Common in adolescents. Euphoria, disinhibition, slurred speech, rash around mouth | Irritability, headaches |
58. A chronic alcoholic presents with confusion, ataxia, and nystagmus. What is the diagnosis?
➔ Wernicke encephalopathy (Alcoholism + confusion + ataxia + eye findings → think Wernicke encephalopathy)
- Note: Wernicke-Korsakoff Syndrome
→ Cause: Thiamine (B₁) deficiency (common in alcoholics).
→ Symptoms:
– Wernicke encephalopathy → Confusion, ataxia, ophthalmoplegia.
– Korsakoff syndrome → Irreversible memory loss, confabulation.
→ Treatment: IV thiamine (before glucose!).
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Pharmacology
59. A schizophrenia patient started on haloperidol complains of inner restlessness and an inability to sit still. What is the treatment?
➔ Propranolol (Symptoms suggestive of Akathisia)
- Note: Extrapyramidal symptoms (EPS) – Common in first-generation antipsychotics:
- Acute dystonia (muscle spasm) → treated with Benztropine.
- Akathisia (restlessness) → treated with β-blockers.
- Parkinsonism (bradykinesia) → treated with Benztropine.
- Tardive dyskinesia (oral/facial chorea) → Valbenazine or deutetrabenazine
60. A long-term haloperidol user has involuntary facial movements and tongue smacking. What is the most likely diagnosis?
➔ Tardive dyskinesia (It is a late-onset, irreversible side effect of first-generation antipsychotics)
- Note: Management:
→ Switching to a second-generation antipsychotic like clozapine
→ VMAT inhibitors (deutetrabenazine and valbenazine).
61. A schizophrenia patient on clozapine presents with fever and neutropenia. What is the next step?
➔ Stop clozapine and start antibiotics (Symptoms indicate Clozapine-induced agranulocytosis)
- Note: Clozapine (Second-generation antipsychotic) → can lead to Agranulocytosis → so we need to monitor WBCs!).
- Other Side Effects of second-generation antipsychotics:
→ Weight gain, diabetes, and hyperlipidemia (mostly in olanzapine).
62. A bipolar patient on a mood stabilizer reports polyuria and tremor. What drug caused this complication?
➔ Lithium (It causes nephrogenic diabetes insipidus, tremor, hypothyroidism)
- Note: Lithium:
→ Uses: Bipolar disorder (acute mania, maintenance)
→ Side Effects:
– Hypothyroidism.
– Ebstein anomaly (teratogenic).
– Nephrogenic DI (polyuria).
– Tremor.
63. A patient being treated for depression complains of inability to orgasm. What is the cause?
➔ SSRI-induced sexual dysfunction
- Note: SSRIs (First-line for Depression, Anxiety)
→ Include Fluoxetine, sertraline, paroxetine, citalopram.
→ Take 4-6 weeks to work.
→ Side Effects: Sexual dysfunction, SIADH, serotonin syndrome.
64. A fibromyalgia patient started on new medication now has elevated blood pressure. What class of medication is this?
➔ SNRI (serotonin-norepinephrine reuptake inhibitor) (Depression medication → leading to ↑ BP → think SNRI)
- Note: SNRIs
→ Include Venlafaxine, duloxetine.
→ Use: Depression, fibromyalgia.
→ Side Effects: ↑ BP.
65. A suicidal patient is found unconscious. EKG shows wide QRS and QT prolongation. What medication likely caused this toxicity?
➔ Tricyclic antidepressant (TCA) overdose (Depression medication → leading to Coma + Cardiotoxicity + Convulsions ‘3Cs’ → think Tricyclic antidepressant (TCA) overdose)
- Note: TCAs
→ Amitriptyline, nortriptyline, imipramine.
→ Use: Neuropathic pain, migraines.
→ Side Effects: QT prolongation, anticholinergic toxicity. - Treatment of overdose: Bicarb (prevents arrhythmia)
66. A man trying to quit smoking asks for a medication that reduces cravings. What do you recommend?
➔ Varenicline (It is a partial nicotinic receptor agonist → reduces cravings)
- Note: Smoking cessation options:
→ Nicotine replacement (gum, patch).
→ Varenicline (partial nicotinic agonist)
→ Bupropion (antidepressant, reduces cravings)
67. A heroin user wants long-term medication to prevent cravings and reduce relapse. What is the best option?
➔ Methadone or buprenorphine
Opioid Use Disorder – Key Treatments:
| Medication | Type | Use |
|---|---|---|
| Methadone | Full opioid agonist | Long-acting → prevents withdrawal/cravings (requires clinic) |
| Buprenorphine | Partial opioid agonist | Safer, office-based treatment |
| Naltrexone | Opioid antagonist | For relapse prevention (must be opioid-free first) |
| Naloxone | Opioid antagonist | For acute overdose reversal |
🏁 Final Thoughts
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Disclaimer
Version 1.0 May 2025. No part of this document may be reproduced or distributed without written permission. For personal study only. Medical information herein is for educational purposes and does not constitute clinical advice. Always confirm with current guidelines and your institution’s policies.
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