6.1 Psychiatry & Behavioral Medicine

Psychiatry & Behavioral Medicine

Behavioral health accounts for 7% of the PANRE blueprint — approximately 17 of the 240 scored questions. Because recertifying physician assistants (PAs) practice across primary care, urgent care, and inpatient settings, the National Commission on Certification of Physician Assistants (NCCPA) tests recognition, first-line management, and safety, not subspecialty psychiatry. Expect single-best-answer vignettes that hinge on a screening tool, a diagnostic time criterion, a drug class, or a contraindication.

This section concentrates on the patterns that recur every cycle. Master the diagnostic time thresholds, the first-line drug for each disorder, and the high-stakes adverse effects, and you will capture nearly all of the points available here.

Why This Topic Matters

• Mood and anxiety disorders are among the most common conditions seen in any PA's panel, so the blueprint over-samples them within the 7%.
• Suicide-risk and acute agitation items are written as must-not-miss safety questions; a single wrong disposition choice can be the difference on a borderline scaled score.
• Psychopharmacology overlaps with the Cardiovascular and Emergent-Topics content, so this material compounds across the exam.

Mood Disorders

Major Depressive Disorder (MDD)

Diagnosis requires ≥ 5 of 9 symptoms for ≥ 2 weeks, with at least one being depressed mood or anhedonia (loss of interest). The mnemonic SIG E CAPS captures the symptom set: Sleep change, loss of Interest, Guilt, low Energy, Concentration deficit, Appetite change, Psychomotor change, Suicidality.

• First-line pharmacotherapy: an SSRI (for example, sertraline, escitalopram). Serotonin-norepinephrine reuptake inhibitors (SNRIs) are reasonable alternatives.
• Onset of effect: 4–6 weeks at a therapeutic dose before judging response. Counsel patients that early activation may precede mood improvement.
• Black-box warning: increased suicidality risk in patients under 25 during initiation — schedule close follow-up.

Bipolar Disorder

• Bipolar I requires at least one manic episode (≥ 1 week of elevated/irritable mood plus increased activity, often with psychosis or hospitalization).
• Bipolar II requires a hypomanic episode plus a major depressive episode and never a full manic episode.
• First-line: lithium, valproate, or an atypical antipsychotic. Do not give an antidepressant alone — it can precipitate a manic switch.
• Lithium monitoring: narrow therapeutic index; check levels, renal function, and thyroid function. Toxicity presents with tremor, ataxia, confusion, and is potentiated by dehydration, thiazides, NSAIDs, and ACE inhibitors.

Anxiety, Trauma & Obsessive-Compulsive Disorders

Benzodiazepine caution: effective for acute anxiety but carry tolerance, dependence, and — in older adults — fall and delirium risk. They are not first-line maintenance therapy. Avoid combining with opioids (additive respiratory depression).

Psychotic Disorders

Schizophrenia

Requires ≥ 6 months of continuous disturbance, including ≥ 1 month of active-phase symptoms (delusions, hallucinations, disorganized speech). Schizophreniform disorder uses the same active symptoms but lasts 1–6 months; brief psychotic disorder lasts 1 day to 1 month with eventual full return to baseline.

• First-line: second-generation (atypical) antipsychotics (for example, risperidone, aripiprazole) — lower extrapyramidal risk than first-generation agents.
• Clozapine is reserved for treatment-resistant schizophrenia and requires absolute neutrophil count monitoring because of agranulocytosis risk; it also carries myocarditis and seizure risk.

Antipsychotic Adverse Effects (High-Yield)

• Extrapyramidal symptoms (EPS): acute dystonia (treat with diphenhydramine or benztropine), akathisia, parkinsonism, and tardive dyskinesia (late, often irreversible).
• Neuroleptic malignant syndrome (NMS): fever, lead-pipe rigidity, autonomic instability, altered mentation, elevated creatine kinase. This is a medical emergency — stop the agent, provide aggressive supportive care, and consider dantrolene or bromocriptine.
• Metabolic syndrome: weight gain, dyslipidemia, and hyperglycemia with atypicals (olanzapine and clozapine are highest risk) — monitor weight, glucose, and lipids.

Substance Use Disorders

Screen with a validated tool and look for the withdrawal syndromes the PANRE loves to test:

• Alcohol withdrawal: tremor and anxiety at 6–24 hours; seizures at 12–48 hours; delirium tremens at 48–96 hours (autonomic instability, confusion — potentially fatal). Treat with benzodiazepines and thiamine; give thiamine before glucose to prevent Wernicke encephalopathy.
• Opioid overdose: miosis, respiratory depression, depressed mental status — reverse with naloxone. Opioid withdrawal is highly uncomfortable but not typically life-threatening; manage symptomatically and offer buprenorphine or methadone for opioid use disorder.
• Benzodiazepine withdrawal: can mimic alcohol withdrawal, including seizures — taper rather than stop abruptly.
• Stimulant intoxication: agitation, mydriasis, hypertension, hyperthermia, chest pain — supportive care and benzodiazepines; avoid beta-blocker monotherapy in cocaine toxicity (unopposed alpha concern).

Pharmacotherapy for alcohol use disorder: naltrexone or acamprosate first-line; disulfiram for highly motivated, supervised patients.

Somatic Symptom, Eating & Neurodevelopmental Disorders

Somatic Symptom & Related Disorders

• Somatic symptom disorder: one or more distressing somatic symptoms plus excessive thoughts/behaviors about them for > 6 months. Manage with a single consistent primary clinician, regular scheduled visits, and CBT — not repeated testing.
• Illness anxiety disorder: preoccupation with having a serious illness despite minimal somatic symptoms.
• Conversion (functional neurological) disorder: neurologic symptoms incompatible with recognized disease.
• Factitious disorder is intentional symptom production for the sick role; malingering is intentional for external gain (not a psychiatric diagnosis).

Eating Disorders

• Anorexia nervosa: restriction leading to low body weight, intense fear of weight gain, body-image disturbance. Watch for refeeding syndrome (hypophosphatemia) when nutrition is restarted — advance calories slowly and monitor electrolytes.
• Bulimia nervosa: binge-purge cycles with normal or above-normal weight; look for hypokalemia, dental erosion, parotid swelling, and Russell sign. SSRIs (fluoxetine) are evidence-based; bupropion is contraindicated because of seizure risk.

Attention-Deficit/Hyperactivity Disorder (ADHD)

Symptoms must be present before age 12, in ≥ 2 settings, and cause functional impairment. First-line treatment is a stimulant (methylphenidate or amphetamine class); obtain a cardiovascular history before starting. Atomoxetine or alpha-2 agonists are non-stimulant alternatives.

Suicide Risk & Psychopharmacology Safety

Suicide-Risk Assessment

Directly ask about ideation, plan, intent, access to means, and prior attempts. Higher-risk features include a specific plan, access to lethal means, prior attempt, recent loss, substance use, and male sex with advancing age. A patient with active ideation plus plan or intent requires immediate safety measures: continuous observation, removal of means, and psychiatric evaluation before any disposition. Do not discharge a high-risk patient on the strength of a verbal "contract for safety" alone.

Cross-Cutting Drug-Safety Pearls

SSRI discontinuation syndrome: flu-like symptoms, dizziness, and sensory disturbances after abrupt stop — taper, especially short-half-life agents like paroxetine.