USMLE (Subject) / Psychiatry (Lesson)

USMLE First Aid

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• Child abuse Physical abuse: - Fractures (eg, ribs, long bone spiral, multiple in differents stages of healing)- Bruises (eg, trunk, ear, neck)- Burns (eg, cigarette, buttocks/thighs)- Subdural hematomas/retinal hemorrhages ("shaken baby syndrome")- During exam, children often avoid eye contact.- Red flags include history inconsistent with degree or type of injury (eg, 2-month-old rolling out of bed or falling down stairs), delayed medical care, caregiver story changes with retelling.- Abuser: Usually biological mother- 40% of deaths related to child abuse or neglect occur in children <1 year old. Sexual abuse:- Genital, anal, or oral trauma; STIs; UTIs- Abuser: Known to victim, usually male- Peak incidence 9-12 years old
• Neurotransmitter changes with disease Alzheimer: ↓ ACh, ↑ glutamate Anxiety: ↑ norepinephrine, ↓ GABA, 5-HT Depression: ↓ norepinephrine, 5-HT, dopamine Huntington disease: ↓ GABA, ACh, ↑ dopamine Parkinson disease; ↓ dopamine, ↑ ACh Schizophrenia: ↑ dopamine
• Rett syndrome X-linked dominant disorder seen almost exclusively in girls (affected males die in utero) Symptoms become apparent around ages 1-4- regression- loss of development- loss of verbal abilities- intellectual disability- ataxia- sterotyped hand-wringing
• Tourette syndrome - Onset before age 18.- Males > Females Characterized by both multiple motor & ≥1 vocal tics that persist for >1 year.- Motor: Facial grimacing, blinking, head/neck jerking, shoulder shrugging, tongue protrusion, sniffing- Vocal: Grunting, snorting, throat clearing, barking, yelling, coprolalia- Coprolalia (involuntary obscene speech) found in only 40% of patients. - Associated with OCD and ADHD. Treatment: psychoeducation, behavioral therapy- For intractable and distressing tics, high-potency antipsychotics (eg, haloperidol, fluphenazine), tetrabenazine (dopamine depleter), α2-agonists (eg, guanfacine, clonidine), or atypical antipsychotics may be used.
• Loss of orientation - alchohol - drugs - fluid/electrolyte imbalance - head trauma - hypoglycemia - infection - nutritional deficiencies
• Delirium "Waxing and waning" level of consciousness with acute onset. Reversible.- Rapid ↓ in attention span and level of arousal. Characterized by:- disorganized thinking- hallucinations (often visual)- misperceptions- disturbance in sleep-wake cycle- cognitive dysfunction- agitation - Usually 2° to other illness (eg, CNS disease, infection, trauma, substance abuse/withdrawal, metabolic/electrolyte disturbances, hemorrhage, urinary/fecal retention).- May be caused by medications (eg, anticholinergics), especially in the elderly. - Most common presentation of altered mental status in inpatient setting, especially in the intensive care unit and with prolonged hospital stays.  - EEG may show diffuse slowing. Treatment is aimed at identifying and addressing underlying condition. Use antipsychotics acutely as needed. Avoid benzodiazepines.
• Dementia ↓ in intellectual function without affecting level of consciousness - memory deficits- apraxia- aphasia- agnosia- loss of abstract thought- behavioral/personality changes - increased risk for dilirium  Irreversible causes: Alzheimer disease, Lewy body dementia, Huntington disease, Pick disease, cerebral infarct, Creutzfeldt-Jakob disease, chronic substance abuseReversible causes: hypothyroidism, depression, vitamin B12 deficiency, hydrocephalus, neurosyphilis - EEG usually normal
• Delusional disorder Diagnosed following one month of nonbizarre delusions that are usually focused around a particulat ropic e.g., infidelity of patient's wife Delusions are not attributable to another psychiatri disorder. Does not markedly impair the person's functioning in daily activities.
• Acting out Expressing unacceptable feelings and thoughts through actions. Example: A young boy throws a temper tantrum when he does not get the toy he wants.
• Denial Avoiding the awareness of some painful reality. Example: A patient with cancer plans a full-time work schedule despite being warned of significant fatigue during chemotherapy.Example: A woman prepares dinner for her husband expecting him to come home, even though he died a month earlier.
• Displacement Redirection of emotions or impulses to a neutral person or object (vs projection). Example: A teacher is yelled at by the principle. Instead of confronting the principal directly, the teacher goes home and criticizes her husband's dinner selection.Example: A woman watching a movie featuring love scenes with a handsome actor goes out and seduces an unattractive man.Example: In family therapy, one whild in a family is often singled out and blamed for all the family's problems, i.e., treated as a scapegoat.
• Dissociation Temporary, drastic change in personality, memory, consciousness, or motor behavior to avoid emotional stress. Patient has incomplete or no memory of traumatic event. Example: A victim of sexual abuse suddenly appears numb and detached when she is exposed to her abuser.
• Fixation Partially remaining at a more childish level of development (vs regression). Example: A surgeon throws a tantrum in the operating room because the last case ran very late.
• Intellectualization Using facts and logic to emotionally distance oneself from a stressful situation. Example: In a therapy session, patient diagnosed with cancer focuses only on rates of survival.Example: A patient with a bone protruding from his leg focuses on the physics that allow such an event to occur.Example: A boy who, for the first time, is about to ask a girl out talks with his friend about the importance of mating rituals for the long-term survival of the species and the mechanisms by which societies arrange for these rituals.
• Isolation (of affect) Separating feelings from ideas and events. Example: Describing murder in graphic detail with no emotional response.
• Projection Attributing an unacceptable internal impulse to an external source (vs displacement). Example: A man who wants to cheat on his wife accuses his wife of being unfaithful.Example: A girl talks about her doll as having certain feelings, which are really what the girl feels.
• Rationalization Proclaiming logical reasons for actions actually performed for other reasons, usually to avoid self-blame. Example: After getting fired, claiming that the job was not important anyway.Example: A murderer saying, "Yes, I believe killing is wrong but I killed him because he really deserved it."Example: An alcoholic man tells his wife that he drinks because of stress at work.
• Reaction formation Replacing a warded-off idea or feeling with an (unconsciously derived) emphasis on its opposite (vs sublimation). Example: A patient with lustful thoughts enters a monastery.Example: A student who wanted to be a physician expresses relief and says, "This is the best news I've ever heard," after not being accepted into medical school.
• Regression Involuntarily turning back the maturational clock and going back to earlier modes of dealing with the world (vs fixation). Example: Seen in children under stress such as illness, punishment, or birth of a new sibling (eg, bedwetting in a previously toilet-trained child).Example: A husband speaks to his wife in "baby talk" when he is sick.Example: A man assumes a fetal position after a traumatic event.
• Repression Involuntarily withholding an idea or feeling from conscious awareness (vs suppression). Example: A 20-year-old does not remember going to counseling during his parents' divorce 10 years earlier.
• Mature defenses Sublimation: Replacing an unacceptable wish with a course of action that is similar to the wish but socially acceptable (vs reaction formation).Example: Teenager's aggressive urges toward his parents' high expectations are channeled into excelling in sports. Altruism: Alleviating negative feelings via unsolicited generosity, which provides gratification (vs reaction formation).Example: Mafia boss makes large donation to charity. Suppression: Intentionally withholding an idea or feeling from conscious awareness (vs repression); temporary.Example: Choosing not to worry about the big game until it is time to play. Humor: Appreciating the amusing nature of an anxiety-provoking or adverse situation.
• Vulnerable child syndrome Parents perceive the child as especially susceptible to illness or injury. - Usually follows a serious illness or life-threatening event. - Can result in missed school or overuse of medical services.
• Attention-deficit hyperactivity disorder - Onset before age 12. - At least 6 months of limited attention span and/or poor impulse control. - Characterized by hyperactivity, impulsivity, and/or inattention in multiple settings (school, home, places of worship, etc).- Normal intelligence, but commonly coexists with difficulties in school. - Often persists into adulthood. Treatment: stimulants (eg, methylphenidate) +/- cognitive behavioral therapy (CBT); alternatives include atomoxetine (noradrenaline uptake inhibitor), α2-agonists (guanfacine, clonidine).
• Malingering Symptoms are intentional, motivation is intentional. Patient consciously fakes, profoundly exaggerates, or claims to have a disorder in order to attain a specific 2˚ (external) gain (eg, avoiding work, obtaining compensation).  - Poor compliance with treatment or follow-up of diagnostic tests.- Complaints cease after gain (vs factitious disorder).
• Factitious disorders Symptoms are intentional, motivation is unconscious. Patient consciously creates physical and/or psychological symptoms in order to assume "sick role" and to get medical attention and sympathy (1˚ [internal] gain). Factitious disorder imposed on self: Also known as Munchausen syndrome. Chronic factitious disorder with predominantly physical signs and symptoms. Characterized by a history of multiple hospital admissions and willingness to undergo invasive procedures. More common in women and healthcare workers. Factitious disorder imposed on another: Also known as Munchausen syndrome by proxy. Illness in a child or elderly patient is caused or fabricated by the caregiver. Motivation is to assume a sick role by proxy. Form of child/elder abuse.
• Somatic symptom and related disorders Symptoms are unconscious, motivation is unconscious. Category of disorders characterized by physical symptoms causing significant distress and impairment. Symptoms not intentionally produces or feigned. More common in women. - Somatic symptom disorder- Conversion disorder- Illness anxiety disorder
• Somatic symptom disorder Variety of bodily complaints (eg, pain, fatigue) lasting for months to years. - Associated with excessive, persistent thoughts and anxiety about symptoms. - May co-occur with medical illness. Treatment: regular office visits with the same physician in combination with psychotherapy
• Conversion disorder Also known as functional neurologic symptom disorder. - Loss of sensory or motor function (eg, paralysis, blindness, mutism), often following an acute stressor.- Patient may be aware of but indifferent toward symptoms ("la belle indifference"). - More common in females, adolescents, and young adults.
• Narcolepsy Disordered regulation of sleep-wake cycles characterized by excessive daytime sleepiness (despite feeling rested upon waking) and "sleep attacks" (rapid-onset, overwhelming sleepiness).  Caused by ↓ hypocretin (orexin) production in lateral hypothalamus. Strong genetic component. Also associated with:- Hypnagogic (just before going to sleep) or hypnopompic (just before awakening) hallucinations.- Nocturnal and narcoleptic sleep episodes that start with REM sleep (sleep paralysis).- Cataplexy (loss of all muscle tone following strong emotional stimulus, such as laughter) in some patients. Treatment: good sleep hygiene (scheduled naps, regular sleep schedule), daytime stimulants (eg, amphetamines, modafinil) and nighttime sodium oxybate (sodium salt of gamma-hydroxybutyric acid, GHB).
• Autism spectrum disorder Characterized by poor social interactions, social communication deficits, repetitive/ritualized behaviors, restricted interests. - Must present early in childhood.- More common in boys. - May be accompanied by intellectual disability; rarely accompanied by unusual abilities (savants). - Associated with ↑ head/brain size.
• Conduct disorder Repetitive and pervasive behavior violating the basic rights of others or societal norms.- Aggression & cruelty toward people & animals- Destruction of property, settinf fires- Serious violation of rules (truancy, running away)- Deceitfulness &/or theft (lying, stealing) - After age 18, often reclassified as antisocial personality disorder. Treatment for both: psychotherapy such as CBT
• Disruptive mood dysregulation disorder Severe and recurrent temper outbursts out of proportion to situation.- Child is constantly angry and irritable between outbursts. - Onset before age 10. Treatment: stimulants, antipsychotics, CBT.
• Oppositional defiant disorder Enduring pattern of hostile, defiant behavior toward authority figures in the absence of serious violations of social norms.- Argues with adults, defies authority figures, refuses to follow rules- Deliberately annoys others- Blames others for own mistakes or misbehavior- Easily annoyed, angered, resentful, or vindictive Treatment: psychotherapy such as CBT.
• Separation anxiety disorder Overwhelming fear of separation from home or attachment figure lasting ≥4 weeks. - Can be normal behavior up to age 3-4. - Commonly experience physical symptoms (eg, headaches, stomach aches, nausea) when separtion occurs or is anticipated.- Repeated nightmares involving the theme of separation.- May lead to factitious physical complaints to avoid school. Treatment: CBT, play therapy, family therapy.
• Depersonalization/derealization disorder Dissociative disorder. Persistent feelings of detachment or estrangement from one's own body, thoughts, perceptions, and actions (depersonalization) or one's environment (derealization). Intact reality testing (vs psychosis).
• Dissociative amnesia Inability to recall important personal information, usually subsequent to severe trauma or stress.
• Dissociative identity disorder Formerly known as multiple personality disorer. Presence of 2 or more distinct identities or personality states.- More common in women. - Associated with history of sexual abuse, PTSD, depression, substance abuse, borderline personality, somatoform conditions. - May be accompanied by dissociative fugue (abrupt travel or wandering associated with traumatic circumstances).
• Psychosis Distorted perception of reality characterized by delusions, hallucinations, and/or disorganized thought/speech. - Can occur in patients with medical illness, psychiatric illness, or both.
• Delusions Presentation of psychosis. Unique, false, fixed, idiosyncratic beliefs that persist despite the facts and are not typical of patient's culture or religion (eg, thinking aliens are communicating with you). Types include:- erotomanic- grandiose- jealous- persecutory- somatic- mixed- unspecified
• Disorganized thought Presentation of psychosis. Speech may be:- incoherent ("word salad")- tangential, eg, in answer to the question "Where are you from", a response "My dog is from England. They have good fish and chips there. Fish breathe through gills."- derailed ("loose associations"), eg, "The next day when I'd be going out you know, I took control, like uh, I put bleach on my hair in California."
• Schizophrenia Chronic mental disorder with periods of psychosis, disturbed behavior and thought, and decline of functioning lasting ≥6 months (including prodrome and residual symptoms). - Associated with ↑ dopaminergic activity, ↓ dendritic branching.- Associated with frequent cannabis use.- Lifetime prevalence – 1.5% (males>females, African Americans=Caucaisans). - Presents earlier in men (late teens to early 20s vs late 20s to early 30s in women).- Patients at ↑ risk for suicide. Diagnosis requires ≥2 of the following symptoms for ≥1 month, and at least 1 of these should include #1-3:1. Delusions2. Hallucinations – often auditory3. Disorganized speech4. Disorganized or catatonic behavior5. Negative symptoms (affective flattening, avolition, anhedonia, asociality, alogia - lack of speech) - Ventriculomegaly on brain imaging Treatment: atypical antipsychotics (eg, risperidone) are first line.- Negative symptoms often persist after treatment, despite resolution of positive symptoms. Brief psychotic disorder – ≥1 positive symptom(s) lasting <1 month, usually stress related.Schizophreniform disorder – ≥2 symptoms, lasting 1-6 months.Schizoaffective disorder – Meets criteria for schizophrenia in addition to major mood disorder (major depressive or bipolar). To differentiate from major mood disorder with psychotic features, patients must have >2 weeks of psychotic symptoms without major mood episode.
• Delusional disorder Fixed, persistent, false belief system lasting >1 month. - Functioning otherwise not impaired (eg, a women who genuinely believes she is married to a celebrity when, in fact, she is not). - Can be shared by individuals in close relationships (folie a deux).
• Manic episode Distinct period of abnormally and persistently elevated, expansive, or irritable mood and abnormally and persistently ↑ activity or energy lasting ≥1 week.- Often disturbing to patient and causes marked functoinal impairment and oftentimes hospitalization. Diagnosis requires hospitalization or at least 3 of the following:- Distractibility- Impulsivity/Indiscretion – seeks pleasure without regard to consequences (hedonistic)- Grandiosity – inflated self-esteem- Flight of ideas – racing thoughts- ↑ goal-directed activity/psychomotor agitation- ↓ need for sleep- Talkativeness or pressured speech
• Hypomanic episode Similar to manic episode except mood disturbance is not severe enough to cause marked impairment in social and/or occupational functioning or to necessitate hospitalization. - No psychotic features. - Lasts ≥4 consecutive days.
• Bipolar disorder Bipolar I defined by presence of at least 1 manic episode +/- a hypomanic or depressive episode (may be separated by any length of time). Bipolar II defined by presence of a hypomanic and a depressive episode (no history of manic episodes). - Patient's mood and functioning usually normalize between episodes. - Use of antidepressants can destabilize mood.- High suicide risk. Treatment: mood stabilizers (eg, lithium, valproic acid, carbamazepine, lamotrigine), atypical antipsychotics. Cyclothymic disorder – milder form of bipolar disorder lasting ≥2 years, fluctuating between mild depressive and hypomanic symptoms.
• Major depressive disorder Episodes characterized by at least 5 of the 9 diagnostic symptoms lasting ≥2 weeks (symptoms must include patient-reported depressed mood or anhedonia). Screen for history of manic episodes to rule out bipolar disorder. Diagnostic symptoms:- Depressed mood- Sleep disturbances- Anhedonia (loss of interest)- Guilt or feelings of worthlessness- Energy loss and fatigue- Concentration problems- Appetite/weight changes- Psychomotor retardation or agitation- Suicidal ideations Patients typically have the following sleep changes:- ↓ slow-wave sleep, ↓ REM latency- ↑ REM early in sleep cycle, ↑ total REM sleep- Repeated nighttime and early-morning awakenings (terminal insomnia) Treatment: CBT and SSRIs are first line. SNRIs, mirtazapine, bupropion can also be considered. Electroconvulsive therapy (ECT) in treatment-resistant patients. Persistent depressive disorder (dysthymia) – often milder, ≥2 depressive symptoms lasting ≥2 years, with no more than 2 months without depressive symptoms. MDD with seasonal pattern – formerly known as seasonal affective disorder. Lasting ≥2 years with ≥2 major depressive episodes associated with seasonal pattern and absence of nonseasonal depressive episodes. Atypical symptoms common (eg, hypersomnia, hyperphagia, leaden paralysis).
• Depression with atypical features Characterized by mood reactivity (able to experience improved mood in response to positive events, albeit briefly), "reversed" vegetative symptoms (hypersomnia, hyperphagia), leaden paralysis (heavy feeling in arms and legs), long-standing interpersonal rejection sensitivity. - Most common subtype of depression. Treatment: CBT and SSRIs are first line. MAO inhibitors are effective but not first line because of their risk profile.
• Postpartum mood disturbances Onset during pregnancy or within 4 weeks of delivery. Maternal (postpartum) blues: 50-85% incidence rate. Characterized by depressed affect, tearfulness, and fatigue starting 2-3 days after delivery. Usually resolves within 10 days. - Treatment: supportive. Follow up to assess for possible postpartum depression. Postpartum depression: 10-15% incidence rate. Characterized by depressed affect, anxiety, and poor concentration for ≥2 weeks. - Treatment: CBT and SSRIs are first line. Postpartum psychosis: 0.1-0.2% incidence rate. Characterized by mood-congruent delusions, hallucinations, and thoughts of harming the baby or self. Risk factors include history of bipolar or psychotic disorder, first pregnancy, family history, recent discontinuation of psychotropic medication. - Treatment: hospitalization and initiation of atypical antipsychotic; if insufficient, ECT may be used.
• Grief The five stages of grief per Kubler-Ross model (may occur in any order):- Denial- Anger- Bargaining- Depression- Acceptance - Other normal grief symptoms: shock, guilt, sadness, anxiety, yearning, and somatic symptoms that usually occur in waves.- Simple hallucinations of the deceased person are common (eg, hearing the deceased speaking).- Any thoughts of dying are limited to joining the deceased (vs pathological grief).- Duration varies widely; usually within 6-12 months. - Pathologic grief is persistent and causes functional impairment. Can meet criteria for major depressive episode.
• Electroconvulsive therapy Rapid-acting method to treat resistant or refractory depression, depression with psychotic symptoms, and acute suicidality.- Induces grand mal seizure while patient is anesthetized. Adverse effects: disorientation, temporary headache, partial anterograde/retrograde amnesia usually resolving in 6 months. - No absolute contraindications.- Safe in pregnany and elderly individuals.

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