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USMLE Step 3 (Fach) / Psychiatry (Lektion)

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• Sleepwalking disorder Non-REM sleep arousal disorder (no memory of dream) Epidemiology:- Discrete episodes are common (up to 7% of adults and 30% of children), but the disorder is rare.- Associated with sleep deprivation, irregular sleep schedules, some medications Etiology: idiopathic or genetic (inherited in 80% of cases) Risk factors:- Stress or fatigue- Obstructive sleep apnea- Nocturnal seizures- Fever- Drugs (e.g., lithium) Clinical features:- Recurrent episodes during the first third of the sleep cycle, including sitting up, walking, or eating (rarely, violence)- Blank stare and difficulty arousing patient during the episode- Followed by amnesia of the event Treatment:- Education and reassurance- Ensuring safe sleep environment to reduce the risk of physical harm or wandering outdoors- In refractory cases, benzodiazepines
• Sleep terror disorder Non-REM sleep arousal disorder (no memory of dream) Epidemiology: Discrete episodes of sleep terrors are relatively common (up to 2% of adults and 20% of children), but the disorder is rare. Etiology: unknown; thought to be genetic (family history) Risk factors:- Stress or fatigue- Obstructive sleep apnea- Nocturnal seizures- Fever- Drugs (e.g., lithium) Clinical features:- Screaming or crying suddenly upon awakening- Intense fear and agitation- Tachypnea, diaphoresis, tachycardia during episodes- Difficulty arousing patients during episodes; patients will often return to sleep and not remember the episode the next day Treatment:- Education and reassurance (disorder is usually self-limited)- Remove dangerous objects from bedroom to reduce risk of self-injury- In refractory cases, benzodiazepines
• REM sleep behavior disorder REM sleep arousal disorder (patient remembers the dream) Epidemiology:- Prevalence: (∼0.5%)- Sex: ♂ > ♀- Usually in older patients (> 50 years) Risk factors: associated with narcolepsy, psychiatric medications, and neurodegenerative disorders   Clinical features:- Physically acting out dreams during sleep (sometimes leading to injury to self or others)- Alert and orientated after awakening Treatment:- Remove dangerous objects from the bedroom to reduce risk of self-injury- If applicable, discontinue causative medications- Benzodiazepines (e.g., clonazepam)- Melatonin receptor agonist
• Nightmare disorder REM sleep arousal disorder (patient remembers the dream) Epidemiology:- Prevalence: up to 2% of adults, most common in early adulthood- Sex: ♀ > ♂ Risk factors: post-traumatic stress disorder (PTSD) Clinical features:- Recurrent frightening dreams during the second half of sleep cycle (middle of the night or early in the morning)- Patient remembers the dream after awakening- Causes functional impairment or distress Treatment:- Reassurance if the disorder is mild- Imagery rehearsal therapy: involves modifying a recurrent nightmare by writing it down and rehearsing new endings that make nightmares less frightening when they occur again- Antidepressants if associated with PTSD
• Oppositional defiant disorder (ODD) Anger, irritable mood, and defiant behavior toward authority figures that significantly impairs social and/or academic functioning Epidemiology:- Onset is usually during late preschool or elementary school years- Before puberty ♂ > ♀; after puberty ♂ = ♀- Frequent comorbidity of ADHD, anxiety, mood disorders, and/or learning disorders Etiology: associated with genetic, environmental, psychological, and/or social factors (e.g., abuse, exposure to toxins, positive family history, neglectful parents, family instability) Diagnostic criteria (according to DSM-5):≥ 4 of the following symptoms for ≥ 6 months when interacting with ≥ 1 individual who is not a sibling (e.g., teachers, parents):- Frequent loss of temper- Easily annoyed- Resentful or angry mood- Argumentative with authority figures- Defies rules or refuses to comply with requests from authority figures- Deliberately annoying- Blames others for one's own mistakes- ≥ 2 episodes of vindictive or spiteful behavior within the past 6 months Disruptive mood dysregulation disorder should be ruled out.The disturbance should negatively impact the individual's functioning or cause distress to other individuals. Treatment: psychotherapy (individual and family), parent management training, social-skills programs Prognosis: often precedes the onset of conduct disorder
• Conduct disorder A repetitive and persistent pattern of disruptive behavior that violates the basic rights of others or age-appropriate societal norms or rules Epidemiology:- Onset during childhood or adolescence- ♂ > ♀ Etiology: associated with genetic, environmental, psychological, and/or social factors (e.g., abuse, exposure to toxins, positive family history, neglectful parents, family instability) Diagnostic criteria (according to DSM-5):- Aggression toward people and animals (e.g., bullying, physical fights, use of weapons)- Destruction of property (e.g., fire setting)- Deceitfulness or theft- Serious rule violation (e.g., truancy, running away from home)- The disturbance in behavior lasts ≥ 12 months and significantly impairs social, academic, and/or occupational functioning.- The diagnosis is only applied to patients < 18 years of age. Treatment:- CBT, parent management training, social skills programs- Pharmacotherapy (e.g., psychostimulants in comorbid ADHD, antipsychotic medications or mood stabilizers in cases of severe aggression) Prognosis: Individuals with CD are at increased risk of developing antisocial personality disorder in adulthood.
• Substance use disorder Pathologic collection of cognitive, behavioral, and physiological symptoms related to the use of a substance Epidemiology:- Sex: ♂ > ♀- Alcohol and nicotine use is most common Criteria:1. Impaired control2. Social impairment3. Risky use4. Pharmacologic indicators- Drug tolerance- Drug withdrawal
• Alcohol use disorder Epidemiology- Prevalence: US lifetime prevalence is ∼ 29%- More common in Native Americans and Alaska Natives than in other US ethnicities- Peak incidence: 21-34 years- Sex: ♂ > ♀ (2.5:1)  Associated comorbidities:- Childhood ADHD- Conduct disorder- Personality disorders (most commonly borderline personality disorder)- Anxiety, mood disorders (e.g., depression, bipolar disorder), and psychosis- Other substance-related disorders (e.g., stimulants, sedatives, cannabis, and other)- Cognitive dysfunction Diagnostics:- Screening: AUDIT-C and CAGE test- Acute alcohol intoxication: high BAC - Chronic alcohol intoxication→ Liver damage: ↑ γ-GT, ↑ ALT, ↑ AST (AST is only higher than ALT when liver parenchyma is significantly damaged)→ Carbohydrate-deficient transferrin (CDT) → Malnutrition and bone marrow damage: ↓ Folic acid, ↓ vitamin B12 (cobalamin), ↓ vitamin B1 (thiamine), ↓ vitamin B6 (pyridoxine), ↓ vitamin D, ↓ vitamin K, megaloblastic anemia (↓ Hb, ↑ MCV), thrombocytopenia   Treatment:- Counseling on alcohol abuse- Psychosocial support (e.g., Alcoholics Anonymous)- Pharmacotherapy (to promote alcohol cessation)→ Naltrexone (first-line agent): reduces cravings for alcohol  → Disulfiram: exacerbates intoxication symptoms and induces negative conditioning  → Acamprosate: blocks central glutamate receptors and reduces cravings for alcohol→ Topiramate or gabapentin: for patients who do not tolerate or respond to other medications- Vitamin supplementation: Vitamin B1 (thiamine), Vitamin B6 (pyridoxine), Vitamin B12 (hydroxocobalamin), Folic acid  
• Delirium Clinical features:- The main symptom is an acute (hours to days) alteration in the level of awareness and attention.- Illusions- Hallucinations- Deficits in memory- Reversal of the sleep-wake cycle- Emotional lability- Agitation, combativeness- The severity of symptoms fluctuates throughout the day and worsens in the evening (termed sundowning).- The duration of symptoms depends on the underlying illness. Diagnostics:- If the cause of delirium is not obvious based on the patient history and physical findings:→ Start with complete blood count, serum glucose, electrolytes, and urinalysis.→ If medication or substance use is suspected: urine toxicology or serum drug levels→ If a metabolic etiology is suspected: serum creatinine, BUN, liver function tests, arterial blood gas→ If pneumonia is suspected: chest x-ray→ If a cardiac etiology (e.g., myocardial infarction, arrhythmia) is suspected: ECG- If the patient has focal neurological deficits or the initial workup is negative, further tests may include:→ Neuroimaging (CT, MRI)  → Lumbar puncture: to rule out meningitis/encephalitis  → EEG: usually shows diffuse slowing of background activity in patients with delirium; also useful in patients with a history of head trauma, stroke, or brain lesions- Further diagnostics that may be considered:→ Blood culture→ HIV; syphilis serology→ Thyroid function tests→ Vitamin B12, folate, and thiamine levels→ Depression screen Treatment:- Identify and treat the underlying cause.- Discontinue the causative medications (e.g., benzodiazepines and anticholinergics).- Manage agitation initially with nonpharmacologic strategies A- dminister antipsychotics if the patient is agitated and/or poses harm to themselves or others.→ Haloperidol is used most commonly; however, it should not be used in patients with delirium that is due to alcohol or benzodiazepine withdrawal because it lowers the seizure threshold.→ Alternative: atypical antipsychotics (e.g., olanzapine)- Maintain adequate hydration and nutrition.- Reduce pain, preferably with nonopioid medications.- Prevent aspiration, incontinence, and skin breakdown.Benzodiazepines are deliriogenic. Do not treat delirious patients with benzodiazepines unless the delirium is due to alcohol or benzodiazepine withdrawal, in which case haloperidol is contraindicated because it lowers the seizure threshold!
• Neuroleptic malignant syndrome (NMS) Life-threatening neurological disorder usually associated with antipsychotics that is characterized by a tetrad of features (fever, muscle rigidity, autonomic instability, and mental status changes) as well as rhabdomyolysis and elevated creatine kinase Etiology:- Reaction to antipsychotic drugs (especially high-potency antipsychotics), other agents that affect the CNS (e.g., carbamazepine, lithium, venlafaxine), or certain antiemetics (e.g., metoclopramide, promethazine)- Genetic predisposition Clinical features:- Onset usually occurs within 2 weeks of the first dose.- Muscle rigidity, akinesia, tremor- Hyperthermia- Autonomic instability (tachycardia, labile blood pressure, tachypnea, diaphoresis, dysrhythmias)- Mental status change: confusion, delirium, reduced vigilance, stupor Diagnostics:- ↑↑ Creatine kinase- Leukocytosis- ↑ Transaminases- Metabolic acidosis- Myoglobinuria- Electrolyte abnormalities (hypocalcemia, hyperkalemia, hyponatremia or hypernatremia)- Low serum iron concentration Treatment:- Discontinuation of the antipsychotic drug!- Supportive measures (e.g., ICU care) Pharmacotherapy:- Dantrolene (ryanodine receptor antagonist): prevents the release of calcium from the sarcoplasmic reticulum of striated muscle → reduced muscle rigidity and hyperthermia- Alternatives: bromocriptine, apomorphine, or amantadine- Benzodiazepines can be administered to treat psychomotor agitation. 
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• Serotonin syndrome A life-threatening condition caused by serotonergic overactivity Cause: can be caused by any drug that increases serotonin levels- Psychiatric drugs: MAOIs, SSRIs, SNRIs, TCAs, vortioxetine, vilazodone, trazodone- Other drugs: tramadol, ondansetron, MDMA, dextromethorphan, meperidine, St. John's wort, triptans, linezolid- Increased risk with:→ Concurrent use of two or more serotonergic drugs→ Switching from one serotonergic drug to another without tapering Clinical features:- Classic triad: neuromuscular excitability, autonomic dysfunction, altered mental status- General: diaphoresis, hyperthermia- Cardiovascular: hypertension, tachycardia  - Gastrointestinal: nausea, vomiting, diarrhea- Psychiatric: delirium, psychomotor agitation, anxiety- Neurological: hypertonia (especially in the lower extremities), hyperreflexia, myoclonus, tremor, horizontal ocular clonus, ataxia, mydriasis, seizure, coma Treatment:- Immediate discontinuation of serotonergic drugs- Supportive care:→ Antihypertensives, fluid replacement→ Benzodiazepines for sedation→ Cyproheptadine: H1, 5-HT1A, and 5-HT2A receptor antagonistsUsed for cases of serotonin syndrome that do not respond to supportive care→ Cooling measures: ice packs and cold compresses
• Alcohol use (abuse) screening CAGE Have you felt you should cut down on your drinking?Have others annoyed you by criticizing your drinking?Have you ever felt bad or guilty about your drinking?Have you ever taken a drink first thing in the morning (eye-opener) to steady your nerves? Single-item screening How many times in the past year have you had 5 (4 for women) or more drinks in a day? AUDIT-C How often do you drink alcohol?How many drinks do you have on a typical day when you are drinking?How often do you have 6 (4 for women) or more drinks on 1 occasion? AUDIT 10-item screen assessing frequency, number of drinks & psychosocial consequences
• Histrionic personality disorder - Pattern of excessive emotionality & attention-seeking behavior since early adulthood - Inappropriate, sexually seductive or provocative behavior; uses appearance to draw attention - Shallow, shifting, dramatic emotions - Impressionistic, vague speech - Suggestible (easily influenced) - Considers relationships more intimate than they really are
• Stages of change model Precontemplation = Not ready to change: patient does not acknowledge negative consequences- Encourage patient to evaluate consequences of current behavior- Explain & personalize the risk- Recommending action is premature Contemplation = Thinking of changing: patient acknowledges consequences but is ambivalent- Encourage evaluation of pros & cons of behavior change- Promote new, positive behaviors Preparation = Ready to change: patient decides to change- Encourage small initial steps- Reinforce positive outcome expectations  Action = Making change: patient makes specific, overt changes- Help identify appropriate change strategies & enlist social support- Promote self-efficacy for dealing with obstacles Maintenance = Changes integrated into patient’s life; focus on relapse prevention- Follow-up support; reinforce intrinsic rewards- Develop relapse prevention strategies Identification = Behavior is automatic: changes incorporated into sense of self- Praise changes
• Contraindications to kidney donation - Age <18- Lack of mental ability to make an informed decision- Uncontrolled hypertension, HIV infection, diabetes mellitus- Active or partially treated cancer- Acute infection- High suspicion of donor coercion- High suspicion of illegal financial exchange from recipient to donor- Uncontrolled psychiatric illness- Active substance abuse
• Assessment & management of suicidality Assessment: SAD PERSONS- Sex- Age- Depression- Previous attempt- EtOH (or other substance) use- Rational thought loss (psychosis)- Social support lacking- Organized plan- No spouse or significant other- Sickness or injury Management:- High imminent risk (ideation, intent & plan)→ Ensure safety: Hospitalize immediately (involuntarily if necessary)→ Remove personal belongings & objects in room that may present self-harm risk→ Constant observation & security may be required to hold against will- High non-imminent risk (ideation, intent, but no plan to act in near future)→ Ensure close follow-up→ Treat modifiable risk factors (underlying depression, psychosis, substance abuse, pain)→ Recruit family or friends to support patient→ Reduce access to potential means (secure firearms, medications)
• Treatment-resistant depression Nonresponder – consider switching- Monotherapy with a different antidepressant- Psychotherapy- Electroconvulsive therapy- Repetitive transcranial magnetic stimulation Partial responder – consider augmentation- Second-line antipsychotic- Antidepressant with different mechanism of action- Lithium- Thyroid hormone- Psychotherapy
• Common drugs affecting lithium levels Drugs that ↑ lithium levels:- Thiazide diuretics- NSAIDs, except aspirin- ACE inhibitors & ARBs- Antibiotics (eg, tetracycline, metronidazole) Drugs that may ↑ or ↓ lithium levels:- Loop diuretics (eg, furosemide)- Calcium channel blockers (eg, verapamil) Drugs that ↓ lithium levels:- Potassium-sparing diuretics- Theophylline
• Suicide assessment – ideation, intent & plan Evaluate ideation:- Wish to die, not wake up (passive)- Thoughts of killing self (active)- Frequency, duration, intensity, controllability Evaluate intent:- Strength of intent to attempt suicide; ability to control impulsivity- Determine how close patient has come to acting on a plan (rehearsal, aborted attempts)- Evaluate plan Specific details: - Method, time, place, access to means (eg, weapons, pills), preparations (eg, gathering pills, changing will)- Lethality of method- Likelihood of rescue
• Suicide risk & protective factors Risk factors:- Psychiatric disorders, prior suicide attempts- Hopelessness  - Never married, divorced, separated- Living alone- Elderly white man- Unemployed or unskilled- Physical illness- Family history of suicide, family discord- Access to firearms- Substance abuse, impulsivity Protective factors:- Social support/family connectedness- Pregnancy- Parenthood- Religion & participation in religious activities
• Catatonia Clinical features:- Immobility or excessive purposeless activity - Mutism, stupor (decreased alertness & response to stimuli)- Negativism (resistance to instructions & movement)- Posturing (assuming positions against gravity)- Waxy flexibility (initial resistance, then maintenance of new posture)- Echolalia, echopraxia (mimicking speech & movements) Management:- Benzodiazepines (lorazepam)- Electroconvulsive therapy
• Lithium toxicity Etiology:- Overdose- Volume depletion- Reduced glomerular filtration- Drug interactions→ Thiazide diuretics→ NSAIDs (not aspirin)→ ACE inhibitors Features:- Acute→ GI: Nausea, vomiting, diarrhea→ Neurologic findings occur much later- Chronic→ Neurologic: Ataxia, confusion, agitation, neuromuscular excitability (tremor) Management:- Lithium levels every 2-4 hours- Intravenous hydration- Bowel irrigation (asymptomatic acute overdose)→ Hemodialysis: > 4 mEq/L→ > 2.5 mEq/L with symptoms or renal failure→ Increasing level despite intravenous fluids
• Refeeding syndrome Complication in treatment of anorexia nerosa Pathophysiology: very rapid increase in daily food intake can cause massive insulin release → increased displacement of magnesium, potassium, and phosphate (shift from extracellular to intracellular) → ↓ phosphate, ↓ potassium, ↓ magnesium Clinical features: edema, tachycardia (torsades de pointes), epileptic seizures, ataxia, rhabdomyolysis Treatment: electrolyte substitution Prophylaxis: monitor electrolyte levels, limit initial dietary intake to 1000-1500 kcal/day
• Alcohol withdrawal syndrome Mild withdrawal:- Anxiety, insomnia, tremors, diaphoresis, palpitations, gastrointestinal upset, intact orientation- Onset since last drink (hr): 6-24 Seizures:- Single or multiple generalized tonic-clonic- Onset since last drink (hr): 12-48 Alcoholic hallucinosis:- Visual, auditory, or tactile; intact orientation; stable vital signs- Onset since last drink (hr): 12-48 Delirium tremens:- Confusion, agitation, fever, tachycardia, hypertension, diaphoresis, hallucinations- Onset since last drink (hr): 48-96
• Schizoaffective disorder DSM-5 criteria:- Major depressive or manic episode concurrent with symptoms of schizophrenia- Lifetime history of delusions or hallucinations for ≥ 2 weeks in the absence of major depressive or manic episode- Mood episodes are prominent & recur throughout illness- Not due to substances or another medical condition Differential diagnosis:- Major depressive or bipolar disorder with psychotic features:  Psychotic symptoms occur exclusively during mood episodes- Schizophrenia:  Mood symptoms may be present for relatively brief periods
• Treatment of end-of-life depression Methylphenidate

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