One hour after undergoing an uncomplicated laparoscopic appendectomy, a 22-year-old man develops agitation and restlessness. He also has tremors, diffuse sweating, headache, and nausea with dry heaves. One liter of lactated ringer's was administered during the surgery and he had a blood loss of approximately 100 mL. His urine output was 100 mL. His pain has been controlled with intravenous morphine. He was admitted to the hospital 3 days ago and has not eaten in 18 hours. He has no history of serious illness. He is a junior in college. His mother has Hashimoto's thyroiditis. He has experimented with intravenous illicit drugs. He drinks 3 beers and 2 glasses of whiskey daily during the week and more on the weekends with his fraternity. He appears anxious. His temperature is 37.4°C (99.3°F), pulse is 120/min, respirations are 19/min, and blood pressure is 142/90 mm Hg. He is alert and fully oriented but keeps asking if his father, who is not present, can leave the room. Mucous membranes are moist and the skin is warm. Cardiac examination shows tachycardia and regular rhythm. The lungs are clear to auscultation. His abdomen has three port sites with clean and dry bandages. His hands tremble when his arms are extended with fingers spread apart. Which of the following is the most appropriate next step in management?

Administer intravenous lorazepam

Administer 5% dextrose in 1/2 normal saline

Administer intravenous naloxone

Administer intravenous propranolol

Administer intravenous dexamethasone

A mental health volunteer is interviewing locals as part of a community outreach program. A 46-year-old man discloses that he has felt sad for as long as he can remember. He feels as though his life is cursed and if something terrible can happen to him, it usually will. He has difficulty making decisions and feels hopeless. He also feels that he has had worsening suicidal ideations, guilt from past problems, decreased energy, and poor concentration over the past 2 weeks. He is otherwise getting enough sleep and able to hold a job. Which of the following statement best describes this patient's condition?

The patient has double depression.

The patient may have symptoms of mania or psychosis.

The patient is likely to show anhedonia.

The patient likely has paranoid personality disorder.

The patient should be started on an SSRI.

A 30-year-old man is brought to the emergency department by the police after starting a fight at a local bar. He has several minor bruises and he appears agitated. He talks incessantly about his future plans. He reports that he has no history of disease and that he is "super healthy" and "never felt better". His temperature is 38.0°C (100.4°F), pulse is 110/min, respirations are 16/min, and blood pressure is 155/80 mm Hg. On physical examination reveals a euphoric and diaphoretic man with slightly dilated pupils. An electrocardiogram is obtained and shows tachycardia with normal sinus rhythm. A urine toxicology screen is positive for cocaine. The patient is held in the ED for observation. Which of the following symptoms can the patient expect to experience as he begins to withdraw from cocaine?

Increased sympathetic stimulation

A 24-year-old woman comes to the physician because she feels sad and has had frequent, brief episodes of crying for the last month. During this period, she sleeps in every morning and spends most of her time in bed playing video games or reading. She has not been spending time with friends but still attends a weekly book club and continues to plan her annual family reunion. She stopped going to the gym, eats more, and has gained 4 kg (8.8 lb) over the past 4 weeks. Three weeks ago, she also started to smoke marijuana a few times a week. She drinks one glass of wine daily and does not smoke cigarettes. She is currently unemployed; she lost her job as a physical therapist 3 months ago. Her vital signs are within normal limits. On mental status examination, she is calm, alert, and oriented to person, place, and time. Her mood is depressed; her speech is organized, logical, and coherent. She denies suicidal thoughts. Which of the following is the most likely diagnosis?

Persistent Depressive Disorder (Dysthymia)

A 67-year-old man comes to the physician for a routine examination. He does not take any medications. He drinks 6 to 7 bottles of beer every night, and says he often has a shot of whiskey in the morning “for my headache.” He was recently fired from his job for arriving late. He says there is nothing wrong with his drinking but expresses frustration at his best friend no longer returning his calls. Which of the following is the most appropriate initial response by the physician?

I'm sorry that your friend no longer returns your calls. What do you think your friend is worried about?

I'm sorry to hear you lost your job. I am concerned about the amount of alcohol you are drinking.

I'm sorry to hear you lost your job. Drinking the amount of alcohol that you do can have very negative effects on your health.

I'm sorry that your friend no longer returns your calls. It seems like your drinking is affecting your close relationships.

I'm sorry that your friend no longer returns your calls. Do you feel that your drinking has affected your relationship with your friend?

A 23-year-old woman is brought to the physician by her father because of irritability, mood swings, and difficulty sleeping over the past 10 days. A few days ago, she quit her job and spent all of her savings on supplies for a “genius business plan.” She has been energetic despite sleeping only 1–2 hours each night. She was diagnosed with major depressive disorder 2 years ago. Mental status examination shows pressured speech, a labile affect, and flight of ideas. Throughout the examination, she repeatedly states “I feel great, I don't need to be here.” Urine toxicology screening is negative. Which of the following is the most likely diagnosis?

Attention-deficit hyperactivity disorder

A 26-year-old female college student is brought back into the university clinic for acting uncharacteristically. The patient presented to the same clinic 6 weeks ago with complaints of depressed mood, insomnia, and weightloss. She had been feeling guilty for wasting her parent’s money by doing so poorly at the university. She felt drained for at least 2 weeks before presenting to the clinic for the first time. She was placed on an antidepressant and was improving but now presents with elevated mood. She is more talkative with a flight of ideas and is easily distractible. Which of the following statements is most likely true regarding this patient’s condition?

Her diagnosis of unipolar depression is incorrect.

The patient may have psychotic features.

The patient may have a history of mania.

Antidepressants are inappropriate.

Her new symptoms need to last at least 7 days.

Substance-induced mood disorders — USMLE Lesson

Core Concepts - Diagnostic Blueprint

Core Feature: A prominent and persistent mood disturbance (e.g., depression, elevated/irritable mood) directly linked to a substance.
DSM-5 Criteria:
- Temporal Link: Symptoms develop during or within 1 month of substance intoxication or withdrawal.
- Causality: Evidence from history, physical exam, or labs confirms the substance is capable of producing the mood symptoms.
- Exclusion: The disturbance is not better explained by an independent mood disorder (e.g., symptoms didn't precede substance use).
- Symptoms do not occur exclusively during a delirium.
- Causes clinically significant distress or functional impairment.

⭐ If mood symptoms persist for a substantial period (e.g., > 1 month) after substance use has stopped, consider an independent mood disorder as the more likely diagnosis.

Causative Agents - The Usual Suspects

Substance-induced mood symptoms must be distinguished from primary mood disorders. The key is the temporal relationship between substance use and mood changes. Symptoms often resolve after cessation.

Substance Class	Manic / Hypomanic States	Depressive States
Stimulants (Cocaine, Amphetamines)	Intoxication	Withdrawal
Depressants (Alcohol, Benzodiazepines)	(Rarely) Intoxication	Intoxication & Withdrawal
Hallucinogens (PCP, LSD)	Intoxication (often with psychosis)	(Less common)
Corticosteroids, Antidepressants	Can induce mania	Withdrawal (Steroids)

Depression: CRASH (Cocaine withdrawal, Reserpine, Alcohol, Steroids, Hypertensives)
Mania: MAD (Medications, Antidepressants, Drugs of abuse)

⭐ Antidepressant monotherapy can unmask or induce mania in up to 15% of patients with undiagnosed Bipolar I Disorder.

Diagnosis & Workup - Clinical Detective Work

Core Principle: Establish a clear temporal relationship between substance use (intoxication or withdrawal) and the onset or exacerbation of mood symptoms.
Clinical Evaluation:
- History: The cornerstone. Meticulously document the type, amount, and frequency of substance use. Crucially, map the timeline of use against the mood disturbance.
- Collateral Information: Obtain history from family or friends, as patient reports may be unreliable.
Diagnostic Testing:
- Labs: Urine Drug Screen (UDS), Blood Alcohol Content (BAC), LFTs, and TSH to exclude other etiologies.

⭐ Key differentiator: If mood symptoms persist for > 1 month after substance cessation, it strongly suggests an independent, primary mood disorder.

Management - The Recovery Plan

Primary Goal: Discontinue the offending substance.
Supportive Care: Essential during withdrawal. Monitor vital signs and ensure patient safety, paying close attention to suicide risk.
Symptomatic Treatment:
- Agitation/Anxiety: Short-term benzodiazepines (e.g., lorazepam).
- Persistent Mood Symptoms: If severe or persisting post-cessation, consider a short course of antidepressants or mood stabilizers.

⭐ Mood symptoms that persist beyond 4 weeks (1 month) after substance cessation suggest an independent, primary mood disorder.

The core feature is the temporal relationship between substance use (intoxication or withdrawal) and the onset of mood symptoms.

Symptoms must be in excess of what is expected from intoxication or withdrawal and warrant independent clinical attention.

Common culprits include alcohol, cocaine, amphetamines, PCP, and corticosteroids.

Symptoms should improve after cessation of the substance; if they persist (typically >1 month post-cessation), consider a primary mood disorder.

Treatment prioritizes stopping the offending agent and providing supportive care.

Unlock the full lesson and continue reading

Signup to continue reading this lesson and unlimited access questions, flashcards, AI notes, and more

Scan to download app

UNLOCK FREE ACCESS