About This Page
This is a clinician-written, evidence-based summary aligned to the USMLE Step 2 CK Content Outline. It is intended for medical students preparing for USMLE Step 2 CK. Management reflects current ACC/AHA, USPSTF, and APA guidelines. Always cross-reference with UpToDate, institutional protocols, and clinical judgment.
The Bottom Line
- USPSTF: screen all adults, including pregnant/postpartum persons and older adults, for major depressive disorder when systems exist for diagnosis and treatment
- USPSTF: screen adults age 19-64, including pregnant/postpartum persons, for anxiety disorders; evidence is insufficient for routine anxiety screening age >=65
- PHQ-2 is a quick initial depression screen; PHQ-9 assesses severity and includes suicidality item 9
- GAD-2 or GAD-7 screens for generalized anxiety symptoms; positive screens require diagnostic assessment
- Suicidal ideation, psychosis, mania, inability to care for self, or danger to others requires urgent safety evaluation
Overview
Depression and anxiety screening identifies common, treatable mental health disorders that often present in primary care with somatic symptoms, sleep disturbance, fatigue, pain, or poor chronic disease control. Screening is not diagnosis: a positive PHQ-9 or GAD-7 must be followed by clinical assessment, differential diagnosis, suicide risk assessment when indicated, and access to evidence-based treatment. Step 2 CK frequently tests the next best step after a positive screen, the meaning of PHQ-9 item 9, and red flags requiring emergency evaluation.
Epidemiology
Major depressive disorder and anxiety disorders are common causes of disability in the United States. Risk is increased by prior mental illness, family history, postpartum state, chronic pain, substance use, trauma, intimate partner violence, serious medical illness, social isolation, housing insecurity, and unemployment. Depression is frequently comorbid with cardiovascular disease, diabetes, obesity, alcohol use disorder, and tobacco use. Perinatal depression and anxiety affect both maternal and infant outcomes.
Screening Features and Red Flags
Symptoms
Depression core symptoms: depressed mood and/or anhedonia plus sleep, appetite, energy, concentration, guilt, psychomotor, and suicidal symptoms
Anxiety symptoms: excessive worry, restlessness, muscle tension, irritability, poor sleep, panic attacks, and impaired functioning
Somatic presentations: fatigue, headache, abdominal pain, chest pain, dizziness, insomnia, or chronic pain without clear organic explanation
Suicidal ideation with intent, plan, access to lethal means, prior attempt, intoxication, psychosis, or hopelessness is an emergency
Mania symptoms: decreased need for sleep, grandiosity, pressured speech, risky behavior — screen for bipolar disorder before antidepressant monotherapy
Postpartum intrusive thoughts, psychosis, command hallucinations, or thoughts of harming infant require urgent evaluation
Signs
Flat affect, tearfulness, psychomotor slowing, agitation, poor eye contact, or impaired concentration may be observed
Disorganized behavior, hallucinations, delusions, catatonia, intoxication, or severe self-neglect signals higher acuity
Weight change, sleep disturbance, tachycardia, tremor, or thyroid enlargement may suggest medical mimics or contributors
Bruising or fearful affect may suggest intimate partner violence and should prompt private safety screening
Screening Tools and Diagnostic Follow-up
First-line
PHQ-2 / PHQ-9PHQ-2 asks about depressed mood and anhedonia. PHQ-9 assesses severity and functional impact; item 9 screens for self-harm thoughts and requires follow-up if positive
GAD-2 / GAD-7Validated tools for anxiety symptom screening and severity monitoring. Positive screen requires diagnostic interview and assessment of impairment
Suicide risk assessmentAssess ideation, intent, plan, means, prior attempts, substance use, psychosis, protective factors, and immediate safety
Second-line
Medical mimic assessmentTSH, CBC, CMP, pregnancy test, B12, substance use assessment, medication review, or sleep disorder evaluation when clinically suggested
Bipolar screeningAsk about manic/hypomanic episodes before starting antidepressants, especially with family history, early-onset depression, or antidepressant activation
Functional and comorbidity assessmentWork, school, relationships, self-care, alcohol/substance use, trauma, IPV, and chronic disease interaction
Specialist
Psychiatry referralFor suicidality, psychosis, bipolar disorder, severe depression, treatment resistance, perinatal complexity, eating disorder, or diagnostic uncertainty
Emergency evaluationActive suicidal intent/plan, homicidal ideation, inability to maintain safety, psychosis, mania with dangerous behavior, or severe postpartum symptoms
Screening Pathway and Initial Management
USPSTF Depression and Anxiety Screening Recommendations 20231
Who to screen
- Depression: screen adults, including pregnant/postpartum persons and older adults, when systems exist for diagnosis, treatment, and follow-up
- Anxiety: screen adults age 19-64, including pregnant/postpartum persons
- Older adults age >=65: evidence is insufficient for routine anxiety screening, but evaluate symptoms when present
- Positive screen is not diagnosis; confirm with clinical assessment
2
Initial treatment options
- Mild depression/anxiety: psychotherapy, guided self-management, exercise, sleep intervention, and close follow-up may be appropriate
- Moderate to severe depression or anxiety: psychotherapy, SSRI/SNRI, or combined treatment depending on patient preference and severity
- Avoid benzodiazepines as first-line chronic anxiety therapy; they carry dependence, fall, and cognitive risks
- Address alcohol, tobacco, sleep apnea, chronic pain, IPV, and social stressors
3
Safety planning
- If suicidal thoughts present: assess plan, intent, means, prior attempts, substance use, psychosis, and supports
- Remove or secure lethal means when risk is present
- Create a written safety plan and arrange rapid follow-up for non-imminent risk
- Hospitalize or emergency evaluate if imminent risk or inability to maintain safety
4
Follow-up and measurement-based care
- Repeat PHQ-9/GAD-7 to monitor response
- Assess adherence, adverse effects, activation/mania, sexual dysfunction, GI symptoms, and sleep
- Antidepressants often take several weeks for meaningful effect; continue treatment after remission to reduce relapse
- Coordinate with therapy, psychiatry, primary care, and community supports
Complications
- Suicide and self-harm: Highest-acuity complication requiring immediate assessment when present
- Functional impairment: Work loss, relationship strain, poor self-care, and disability
- Medical comorbidity: Worse diabetes, cardiovascular disease, chronic pain, insomnia, and substance use outcomes
- Medication complications: SSRI sexual dysfunction, GI upset, serotonin syndrome risk with interacting drugs, and manic switch in bipolar disorder
- Perinatal harms: Poor prenatal care, preterm birth association, impaired bonding, and postpartum safety concerns when severe
USMLE Step 2 CK Exam Tips
- 1Positive PHQ-9 item 9 requires suicide risk assessment — do not ignore it as just a score component
- 2Screening is appropriate only if systems exist for diagnosis, treatment, and follow-up
- 3Before antidepressant monotherapy, ask about mania/hypomania to avoid precipitating mania in bipolar disorder
- 4Depression screening includes pregnant and postpartum patients
- 5Anxiety screening under USPSTF is for adults 19-64; evidence is insufficient for routine screening age >=65
- 6Active suicidal plan/intent/access to means = emergency evaluation or hospitalization
- 7Benzodiazepines are not first-line long-term treatment for generalized anxiety disorder
- 8Somatic symptoms with normal workup can still represent depression/anxiety, but red flags require medical evaluation
practicetest your knowledge on depression & anxiety screeningApply what you've learnt with USMLE Step 2 CK-style questions from the iatroX Q-Bank — preventive medicine and beyond.
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