A 23-year-old man presents to an outpatient psychiatrist complaining of anxiety and a persistent feeling that “something terrible will happen to my family.” He describes 1 year of vague, disturbing thoughts about his family members contracting a “horrible disease” or dying in an accident. He believes that he can prevent these outcomes by washing his hands of “the contaminants” any time that he touches something and by performing praying and counting rituals each time that he has unwanted, disturbing thoughts. The thoughts and rituals have become more frequent recently, making it impossible for him to work, and he expresses feeling deeply embarrassed by them. Which of the following is the most effective treatment for this patient's disorder?

Cognitive behavioral therapy and fluoxetine

Psychodynamic psychotherapy and citalopram

Cognitive behavioral therapy and haloperidol

Cognitive behavioral therapy and clonazepam

Psychodynamic psychotherapy and aripiprazole

A 23-year-old woman is brought to the emergency department by her friend because of strange behavior. Two hours ago, she was at a night club where she got involved in a fight with the bartender. Her friend says that she was smoking a cigarette before she became irritable and combative. She repeatedly asked “Why are you pouring blood in my drink?” before hitting the bartender. She has no history of psychiatric illness. Her temperature is 38°C (100.4°F), pulse is 100/min, respirations are 19/min, and blood pressure is 158/95 mm Hg. Examination shows muscle rigidity. She has a reduced degree of facial expression. She has no recollection of her confrontation with the bartender. Which of the following is the most likely primary mechanism responsible for this patient's symptoms?

Stimulation of cannabinoid receptors

Inhibition of norepinephrine, serotonin, and dopamine reuptake

Stimulation of 5HT2A and dopamine D2 receptors

Inhibition of dopamine D2 receptors

A 75-year-old woman presents to her primary care physician with her son because she is convinced that people are stealing from her. Her son claims she has been misplacing her medications and money throughout the house. She recently lost her husband to old age and has become reclusive and no longer wants people to visit. Physical examination is unremarkable and the patient is oriented to person, time, and place. A mini-mental status examination (MMSE) is performed and she has difficulty recalling words after 5 minutes and also has problems with serial subtraction. Which of the following is the most likely diagnosis in this patient?

Histrionic personality disorder

A 28-year-old male presents to his primary care physician with complaints of intermittent abdominal pain and alternating bouts of constipation and diarrhea. His medical chart is not significant for any past medical problems or prior surgeries. He is not prescribed any current medications. Which of the following questions would be the most useful next question in eliciting further history from this patient?

"Can you tell me more about the symptoms you have been experiencing?"

"Does the diarrhea typically precede the constipation, or vice-versa?"

"Is the diarrhea foul-smelling?"

"Please rate your abdominal pain on a scale of 1-10, with 10 being the worst pain of your life"

"Are the symptoms worse in the morning or at night?"

Cognitive symptoms for USMLE Step 3: High-Yield Psychiatry Lessons

Cognitive Domains - The Thought Tangle

Core feature, strongly predicting real-world functioning (e.g., employment, social relationships). Often precedes the first psychotic episode and persists.

Key Deficits:
- Executive Function: ↓ planning, problem-solving, cognitive flexibility. Assessed via Wisconsin Card Sorting Test (WCST).
- Working Memory: ↓ ability to hold & manipulate information for short periods.
- Attention/Vigilance: ↓ sustained focus.
- Processing Speed: Slowed thinking and reaction time.

⭐ Cognitive impairment is a better predictor of poor long-term functional outcome than the severity of positive or negative symptoms.

Neuropsychological Tests for 6 Cognitive Domains

Neurobiology - Brain's Wiring Woes

Dopamine (Mesocortical Pathway): ↓ Dopamine activity at D1 receptors in the prefrontal cortex (PFC) is strongly linked to executive dysfunction and working memory deficits.
Glutamate (NMDA Receptor): Primary hypofunction is a core deficit, preceding dopamine dysregulation.
- Reduces excitatory signaling, impairing long-term potentiation (LTP), synaptic plasticity, and learning.
GABA Interneurons: ↓ firing of parvalbumin-containing inhibitory interneurons disrupts network gamma-wave synchrony, crucial for working memory and cognitive coordination.
Structural Correlates: Enlarged ventricles and reduced cortical volume (hippocampus, prefrontal cortex) reflect neuronal loss and connectivity issues.

⭐ Phencyclidine (PCP), an NMDA receptor antagonist, can induce a state that closely mimics the full spectrum of schizophrenic symptoms, including severe cognitive impairment, providing strong evidence for the glutamate hypothesis.

Dopamine and glutamate pathways in schizophrenia

Assessment & Impact - Sizing Up the Struggle

Formal Assessment:
- MCCB (MATRICS Consensus Cognitive Battery): Gold standard for clinical trials; comprehensive.
- BACS (Brief Assessment of Cognition in Schizophrenia): Shorter, practical for clinical settings.
- MoCA (Montreal Cognitive Assessment): Useful as a general screen for cognitive deficits.
Functional Impact:
- Cognitive deficits are a core feature, not just a medication side effect.
- Strongly predict day-to-day dysfunction (e.g., employment, social life).
- Often the most debilitating aspect and primary driver of long-term disability.

⭐ Cognitive impairment is a stronger predictor of poor real-world functioning than the severity of positive or negative symptoms.

Cognitive Test Scores: Patients vs. Controls

Management - Retraining the Brain

Cognitive Remediation Therapy (CRT) is a behavioral intervention to improve cognitive deficits, enhancing real-world functioning.

Goal: Target enduring cognitive symptoms often unresponsive to antipsychotics.
- Improves attention, processing speed, working memory, and executive functions.
Methods:
- Repetitive, computer-based "brain training" exercises.
- Strategy coaching to translate cognitive gains to daily life.
- Often integrated with vocational rehabilitation and social skills training.
Two Main Approaches:
- Restorative: Aims to restore lost cognitive functions through drills.
- Compensatory: Teaches strategies to bypass or minimize deficits.

Cognitive Remediation Impact on Work Quality

⭐ High-Yield: The primary goal of CRT isn't just to improve test scores, but to enhance real-world outcomes like independent living and employment. Its efficacy is highest when combined with vocational rehabilitation.

High‑Yield Points - ⚡ Biggest Takeaways

Cognitive symptoms are a core feature of schizophrenia, strongly predicting poor functional outcomes.

Executive dysfunction is prominent, affecting planning, problem-solving, and abstract thought.

Deficits in working memory, attention, and processing speed are common and persistent.

These symptoms often exist before the first psychotic episode and are relatively resistant to antipsychotic treatment.

Impaired social cognition hinders the ability to understand social cues and intentions, impacting relationships.

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