Ch10: Depression, Anxiety & PTSD（抑郁症、焦虑症与创伤后应激障碍）

Preparatory Mindset

The "Big Three" adult mental disorders — depression, anxiety, PTSD — are the focus of this chapter (CM exam tested). The lecture (10 Depression anxiety PTSD, 5.6KB) covers DSM-5 criteria, subtypes, and treatment. The exam tests: DSM-5 Mood & Anxiety disorders criteria, PTSD criteria, the cognitive triad of depression, anxiety disorder types, and the multimodal treatment approach (medication + psychotherapy).

Exam mindset: know the DSM-5 depression criteria (≥5 of 9 symptoms for ≥2 weeks including depressed mood or anhedonia), anxiety disorder taxonomy (GAD, panic, social anxiety, specific phobia), and PTSD criteria (trauma + re-experiencing + avoidance + arousal + ≥1 month).

Core Concepts

1. Depression (MUST KNOW)

• Definition: people with depression experience persistent feelings of sadness and hopelessness and lose interest in activities they once enjoyed
• Somatic symptom: chronic pain, digestive issues
• To be diagnosed: symptoms must be present for at least 2 weeks

2. DSM-5 Major Depressive Disorder (MUST KNOW — 9 symptoms, ≥5, ≥2 weeks, must include #1 or #2)

1. Depressed mood most of the day, nearly every day
2. Markedly diminished interest or pleasure (anhedonia) in all, or almost all, activities
3. Significant weight loss when not dieting or weight gain
4. A slowing down of thought and a reduction of physical movement (psychomotor retardation)
5. Fatigue or loss of energy nearly every day
6. Feelings of worthlessness or excessive or inappropriate guilt
7. Diminished ability to think or concentrate, or indecisiveness
8. Recurrent thoughts of death, suicidal ideation, or suicide attempt
9. Insomnia or hypersomnia

• Mnemonic: SIG-E-CAPS — Sleep, Interest, Guilt, Energy, Concentration, Appetite, Psychomotor, Suicide
• Subtypes: melancholic, atypical, psychotic, seasonal (winter — SAD), peripartum
• Bipolar disorder: alternating mania/hypomania with depression (Bipolar I = mania; Bipolar II = hypomania)

3. Anxiety disorders (MUST KNOW)

- Generalized Anxiety Disorder (GAD): excessive worry about multiple things for ≥6 months; restlessness, fatigue, difficulty concentrating, muscle tension, sleep disturbance - Panic Disorder: recurrent panic attacks (sudden onset of intense fear, peak in minutes); 4+ symptoms (palpitations, sweating, trembling, shortness of breath, chest pain, nausea, dizziness, derealization, fear of dying, paresthesia); anticipatory anxiety leads to agoraphobia (fear of places where escape is difficult) - Social Anxiety Disorder (Social Phobia): fear of social scrutiny → anxiety, blushing, avoidance - Specific Phobia: fear of a specific object/situation (animals, heights, blood) - Agoraphobia: fear of places where escape is difficult (open spaces, crowds, public transport) - Separation Anxiety Disorder, Selective Mutism - Substance/Medication-induced anxiety disorder

• Definition: a type of mental health condition where people respond to certain things/situations with fear and dread; physical signs (pounding heart, sweating)
• Types (DSM-5):

4. Anxiety symptoms (4 categories)

• Cardiovascular: palpitations, tachycardia, chest pain
• Respiratory: shortness of breath, hyperventilation
• GI: nausea, abdominal pain, diarrhea
• Neurological: tremor, dizziness, paresthesia, derealization
• Cognitive: fear of losing control, fear of dying

5. PTSD (Posttraumatic Stress Disorder) (MUST KNOW)

- Intrusion (re-experiencing): flashbacks, nightmares, intrusive thoughts, distress on exposure to cues - Avoidance: of thoughts, feelings, people, places associated with the trauma - Negative alterations in cognition & mood: guilt, shame, distorted beliefs, emotional numbness, dissociation - Hyperarousal: sleep disturbances, irritability, hypervigilance, startle response, concentration difficulty

• Trauma exposure: actual/threatened death, serious injury, or sexual violence (combat, assault, accident, disaster)
• DSM-5 criteria (≥1 month):
• Acute stress disorder: <1 month
• Complex PTSD: prolonged trauma + emotional dysregulation, interpersonal difficulties (in ICD-11)
• Risk factors: severity, prior trauma, female sex, low SES, lack of support
• Comorbidities: depression, substance use, suicide risk

6. Etiology / biopsychosocial model

• Biological: genetic predisposition, neurotransmitter dysregulation (serotonin, norepinephrine, dopamine, GABA, glutamate), HPA axis dysregulation, structural brain changes (amygdala, hippocampus, prefrontal cortex)
• Psychological: early adversity, negative cognition (Beck's cognitive triad), learned helplessness (Seligman)
• Social: stressful life events, chronic stress, lack of support, trauma

7. Treatment (MUST KNOW)

- Pharmacotherapy: SSRIs (first-line, e.g., sertraline, escitalopram), SNRIs (venlafaxine, duloxetine), TCAs (imipramine, amitriptyline — cardiac toxicity in overdose), MAOIs (rare, dietary restrictions) - Psychotherapy: CBT (most evidence-based), IPT (interpersonal therapy), behavioral activation, MBCT (relapse prevention), psychodynamic, & for severe depression: ECT (electroconvulsive therapy) - TMS (transcranial magnetic stimulation), ketamine (treatment-resistant) - Suicide risk assessment: ideation, plan, means, timing, protective factors

- Pharmacotherapy: SSRIs/SNRIs (first-line for long-term), benzodiazepines (short-term, risk of dependence), buspirone, pregabalin - Psychotherapy: CBT (exposure, cognitive restructuring), exposure therapy (systematic desensitization), relaxation, mindfulness

- Trauma-focused CBT (TF-CBT), EMDR (eye movement desensitization and reprocessing), prolonged exposure (PE), cognitive processing therapy (CPT), narrative exposure therapy - SSRIs (sertraline, paroxetine — FDA-approved for PTSD) - Brief eclectic psychotherapy, group therapy

• Depression:
• Anxiety:
• PTSD:

8. Cognitive triad of depression (Beck)

• Negative view of self ("I am inadequate")
• Negative view of the world ("The world is hostile")
• Negative view of the future ("Things will never get better")
• Treatment: identify and dispute these distorted thoughts

9. Suicidal patient (MUST KNOW)

• Risk assessment: SI (ideation), plan, means, intent, timing, prior attempt; protective factors: reasons for living, support, religion/spirituality
• SAFE: S — Specify the plan; A — Available means; F — Frequency of thoughts; E — Escape plan
• Intervention: remove means, hospitalize if needed, start SSRI, therapy, follow-up, family involvement

High-Yield Points

• Depression: ≥5 of 9 symptoms for ≥2 weeks including depressed mood or anhedonia (Mnemonic: SIG-E-CAPS)
• Anxiety types: GAD (6 months), panic (4+ symptoms + agoraphobia), social anxiety, specific phobia, agoraphobia
• PTSD criteria: trauma + intrusion + avoidance + negative cognitions + hyperarousal (≥1 month)
• First-line pharmacotherapy: SSRIs (depression, anxiety, PTSD)
• Benzodiazepines: short-term for anxiety; tolerance & dependence risk
• CBT: evidence-based for depression, anxiety, PTSD
• Beck's cognitive triad: negative self, world, future
• Suicide risk: SI, plan, means, intent, prior attempt; remove means
• ECT: for severe/treatment-resistant depression
• EMDR & trauma-focused CBT: for PTSD
• Anxiety symptoms: 4 categories (cardiovascular, respiratory, GI, neurological)

Topic Summary

Depression (DSM-5 Major Depressive Disorder) requires ≥5 of 9 symptoms for ≥2 weeks, including depressed mood or anhedonia (mnemonic: SIG-E-CAPS — Sleep, Interest, Guilt, Energy, Concentration, Appetite, Psychomotor, Suicide). Anxiety disorders include GAD (≥6 months of excessive worry), Panic Disorder (recurrent panic attacks with 4+ symptoms ± agoraphobia), Social Anxiety Disorder, specific phobias, and agoraphobia. PTSD follows exposure to trauma with ≥1 month of intrusive re-experiencing, avoidance, negative cognitions/mood, and hyperarousal. Etiology is biopsychosocial — biological (genetic, serotonin/norepinephrine/GABA dysregulation, HPA axis), psychological (Beck's cognitive triad, learned helplessness), social (stress, trauma, lack of support). Treatment: SSRIs are first-line for depression, anxiety, and PTSD; CBT is the most evidence-based psychotherapy; anxiety also uses benzodiazepines (short-term) and exposure therapy; PTSD also uses EMDR, prolonged exposure, and cognitive processing therapy (CM exam tested). Suicidal patients need safety planning (remove means, hospitalization), risk assessment, and ongoing follow-up.