Module 4: Anxiety disorders

Section 1: DSM-5 Information

1. Conceptual Foundation & Core Distinctions

• Fear vs. Anxiety: DSM-5 explicitly differentiates fear from anxiety1:

  • Fear: The emotional response to a real or perceived imminent threat, associated with surges of autonomic arousal necessary for fight-or-flight, thoughts of immediate danger, and escape behaviors1.

  • Anxiety: The anticipation of future threat, associated with muscle tension, vigilance in preparation for future danger, and cautious or avoidant behaviors1.

• General Duration Threshold: Anxiety disorders require symptoms to be persistent, typically lasting 6 months or more, to distinguish pathological states from transient, stress-induced fears23.

2. Generalized Anxiety Disorder (GAD) (F41.1 / 300.02)

• Diagnostic Criteria:

  • Criterion A: Excessive anxiety and worry (apprehensive expectation), occurring more days than not for at least 6 months, about a number of events or activities (such as work or school performance)45.

  • Criterion B: The individual finds it difficult to control the worry46.

  • Criterion C: The anxiety and worry are associated with three (or more) of the following 6 symptoms (with at least some symptoms present for more days than not for the past 6 months). Note: Only one item is required in children4more_horiz:

    1. Restlessness or feeling keyed up or on edge46.

    2. Being easily fatigued46.

    3. Difficulty concentrating or mind going blank46.

    4. Irritability46.

    5. Muscle tension46.

    6. Sleep disturbance (difficulty falling or staying asleep, or restless, unsatisfying sleep)46.

  • Criterion D: Causes clinically significant distress or functional impairment67.

  • Criterion E & F: Not attributable to substance/medication or medical condition, and not better explained by another mental disorder6more_horiz.

• Epidemiology & Etiology: 12-month prevalence is ~0.9% in adolescents and 2.9% in US adults9. Females are twice as likely as males to be diagnosed (2:1 ratio)210. Approximately one-third of the risk is genetic, overlapping strongly with neuroticism and major depressive disorder11.

3. Social Anxiety Disorder (Social Phobia) (F40.10 / 300.23)

• Diagnostic Criteria:

  • Criterion A: Marked fear or anxiety about one or more social situations in which the individual is exposed to possible scrutiny by others (e.g., social interactions, being observed, performing)1213. In children, anxiety must occur in peer settings, not just with adults1213.

  • Criterion B: Fears acting in a way or showing anxiety symptoms that will be negatively evaluated (humiliated, embarrassed, rejected, or offending others)1214.

  • Criterion C: Social situations almost always provoke fear or anxiety1415.

  • Criterion D: Situations are actively avoided or endured with intense fear/anxiety1415.

  • Criterion E: Fear/anxiety is out of proportion to actual threat and sociocultural context1516.

  • Criterion F: Persistent, typically lasting 6 months or more1516.

  • Criterion G–J: Causes distress/impairment; not attributable to substance, medical condition, or another mental disorder16more_horiz.

• Specifier: Performance only — assigned if the fear is restricted to speaking or performing in public1819.

• Epidemiology: 12-month US prevalence is ~7%20. Onset is typically in early adolescence (median age ~13 years). High comorbidity with Avoidant Personality Disorder2122.

4. Specific Phobia (300.29)

• Diagnostic Criteria:

  • Criterion A: Marked fear or anxiety about a specific object or situation (e.g., flying, heights, animals, receiving an injection, seeing blood)2324.

  • Criterion B: Phobic stimulus almost always provokes immediate fear or anxiety2325.

  • Criterion C: Actively avoided or endured with intense fear/anxiety2325.

  • Criterion D & E: Out of proportion to actual danger; persistent, typically lasting 6 months or more23more_horiz.

  • Criterion F & G: Causes distress/impairment; not better explained by another mental disorder25more_horiz.

• Subtype Specifiers:

  • Animal (F40.218)2930

  • Natural environment (F40.228; e.g., heights, storms, water)2930

  • Blood-injection-injury (F40.230–F40.233)2930

  • Situational (F40.248; e.g., airplanes, elevators, enclosed places)2930

  • Other (F40.298; e.g., choking, vomiting)2930

• Unique Physiological Marker: Blood-injection-injury phobia uniquely produces a biphasic vasovagal response (initial brief acceleration of heart rate and elevation of blood pressure followed by a rapid deceleration of heart rate and drop in blood pressure, frequently causing syncope/fainting)31.

5. Panic Disorder (F41.0 / 300.01)

• Diagnostic Criteria:

  • Criterion A: Recurrent unexpected panic attacks3233.

  • Criterion B: At least one attack has been followed by 1 month (or more) of one or both of the following3435:

    1. Persistent concern or worry about additional panic attacks or their consequences (e.g., losing control, heart attack, "going crazy")34more_horiz.

    2. A significant maladaptive change in behavior related to the attacks (e.g., avoidance of exercise or unfamiliar situations)3637.

  • Criterion C & D: Not attributable to substance/medical condition or another mental disorder36more_horiz.

• Unlinking from Agoraphobia: In DSM-5, Panic Disorder and Agoraphobia are unlinked into two separate, independent diagnoses339. If an individual meets criteria for both, both codes are assigned3more_horiz.

6. Panic Attack Specifier

• Definition: An abrupt surge of intense fear or intense discomfort that reaches a peak within minutes, during which time 4 (or more) of 13 symptoms occur3242:

  1. Palpitations, pounding heart, or accelerated heart rate3242.

  2. Sweating3242.

  3. Trembling or shaking3242.

  4. Sensations of shortness of breath or smothering3242.

  5. Feelings of choking3242.

  6. Chest pain or discomfort3242.

  7. Nausea or abdominal distress3242.

  8. Feeling dizzy, unsteady, light-headed, or faint3242.

  9. Chills or heat sensations3242.

  10. Paresthesias (numbness or tingling sensations)3442.

  11. Derealization (unreality) or depersonalization (detached from self)3442.

  12. Fear of losing control or "going crazy"3442.

  13. Fear of dying3442.

• Application: Panic Attack is not a standalone mental disorder42. It serves as a cross-cutting descriptive specifier (e.g., "Posttraumatic Stress Disorder with panic attacks") across any DSM-5 diagnostic class4243.

7. Agoraphobia (F40.00 / 300.22)

• Diagnostic Criteria:

  • Criterion A: Marked fear or anxiety about two (or more) of the following five situations4445:

    1. Using public transportation (automobiles, buses, trains, planes)4445.

    2. Being in open spaces (parking lots, marketplaces, bridges)4445.

    3. Being in enclosed places (shops, theaters, cinemas)4445.

    4. Standing in line or being in a crowd4445.

    5. Being outside of the home alone4445.

  • Criterion B: Fears or avoids these situations because of thoughts that escape might be difficult or help might not be available in the event of developing panic-like or other incapacitating/embarrassing symptoms44more_horiz.

  • Criterion C–G: Situations almost always provoke fear/anxiety; actively avoided or requires companion; out of proportion; persistent for 6 months or more; causes distress/impairment4647.

Section 2: ICD-10 Information

1. Structural Overview (Block F40–F48)

• Chapter V Block F40–F48: Entitled Neurotic, stress-related and somatoform disorders48.

• Phobic Anxiety Disorders (F40): Anxiety is evoked predominantly or exclusively in well-defined, non-dangerous situations, leading to characterist avoidance49.

• Other Anxiety Disorders (F41): Manifestations of anxiety are primary and not restricted to any particular environmental situation50.

2. Phobic Anxiety Disorders (F40)

• F40.0 Agoraphobia:

  • Clinical Cluster: Fears of leaving home, entering shops, crowds, public places, or traveling alone51.

  • Hierarchical Subtypes:

    • F40.00 Agoraphobia without history of panic disorder52

    • F40.01 Agoraphobia with panic disorder (Panic disorder is viewed as secondary/linked to the agoraphobic fear)5152.

• F40.1 Social Phobias:

  • Clinical Picture: Fear of scrutiny by other people leading to avoidance of social situations52. Often presents with secondary somatic manifestations: blushing, hand tremor, nausea, or urgency of micturition52. May progress to panic attacks within social settings52.

• F40.2 Specific (Isolated) Phobias:

  • Clinical Picture: Phobias restricted to highly specific situations (animals, heights, thunder, darkness, flying, enclosed spaces, blood/injury)53.

3. Other Anxiety Disorders (F41)

• F41.0 Panic Disorder [Episodic Paroxysmal Anxiety]:

  • Core Feature: Recurrent severe attacks of anxiety (panic) that are not restricted to any particular situation or set of circumstances and are therefore unpredictable50.

  • Exclusion Rule: Panic disorder should not be given as the primary diagnosis if the patient has a depressive disorder at the time the attacks start, or if panic attacks occur strictly within agoraphobic situations (coded under F40.01)5054.

• F41.1 Generalized Anxiety Disorder:

  • Core Feature: Anxiety that is generalized and persistent, but not restricted to any particular environmental circumstances ("free-floating")54.

  • Diagnostic Features: Dominant symptoms are variable but must include persistent manifestations of autonomic arousal (nervousness, trembling, muscle tension, sweating, lightheadedness, palpitations, dizziness, epigastric discomfort)54. Duration requirement in diagnostic guidelines is at least 6 months.

• F41.2 Mixed Anxiety and Depressive Disorder:

  • Core Feature: Assigned when symptoms of both anxiety and depression are present, but neither is clearly predominant, and neither type of symptom is severe enough individually to justify a standalone diagnosis55.

Section 3: Side-by-Side Comparison Table

Section 4: Narrative Comparison & High-Yield Summary

Narrative Analysis

1. The Decoupling of Panic Disorder and Agoraphobia: The most significant conceptual divergence between DSM-5 and ICD-10 lies in the structural relationship between Panic Disorder and Agoraphobia. DSM-5 unlinked the two conditions based on epidemiological and genetic data showing that a substantial proportion of individuals experience agoraphobia without preceding panic attacks3. Consequently, DSM-5 treats Panic Disorder and Agoraphobia as distinct, independent diagnoses that are dual-coded when both criteria sets are met3more_horiz. ICD-10 maintains the classical hierarchical linkage, categorizing Panic Disorder with Agoraphobia under F40.01 and reserving standalone Panic Disorder (F41.0) strictly for situations where panic occurs outside agoraphobic settings50more_horiz.

2. Panic Attack as a Cross-Cutting Specifier: DSM-5 elevated the Panic Attack to a universal, cross-cutting descriptive specifier that can be attached to any mental or medical condition (e.g., Major Depressive Disorder with panic attacks) to denote heightened clinical severity, suicide risk, and treatment resistance4243. ICD-10 views panic attacks primarily as the constituent unit of Panic Disorder (F41.0) or as a severe acute symptom manifestation of phobic avoidance5054.

3. GAD Diagnostic Architecture & Autonomic Arousal: DSM-5 standardized GAD diagnosis around excessive worry and 3 out of 6 central physical/cognitive symptoms (restlessness, fatigue, concentration deficit, irritability, muscle tension, sleep disturbance), reducing the required threshold to 1 symptom in children4more_horiz. In contrast, ICD-10 places strong emphasis on autonomic hyperarousal (e.g., sweating, tachycardia, tremors, epigastric distress), requiring at least one mandatory autonomic symptom alongside generalized tension54.

4. Subthreshold Entities: ICD-10 provides a dedicated, highly utilized primary care code for F41.2 Mixed anxiety and depressive disorder for subthreshold co-occurring anxiety and depression55. DSM-5 lacks a direct Section II equivalent, requiring clinicians to code such presentations under Other Specified Anxiety Disorder or Adjustment Disorder with mixed anxiety and depressed

High-Yield Discrepancy Summary for Exam Retention

• Panic & Agoraphobia Decoupling:

  • DSM-5: Unlinked; two independent diagnoses (Panic Disorder + Agoraphobia)3more_horiz.

  • ICD-10: Linked; coded as F40.01 Agoraphobia with panic disorder5152.

• Panic Attack Specifier:

  • DSM-5: Universal specifier applicable across all DSM-5 chapters4243.

  • ICD-10: Symptom entity within F41.0 or phobias5054.

• GAD Child Symptom Threshold:

  • DSM-5: Requires only 1 of 6 physical/cognitive symptoms in children46.

  • ICD-10: Standard criteria apply across age groups (autonomic arousal required)54.

• GAD Autonomic Requirement:

  • DSM-5: Autonomic symptoms are associated features, not mandatory for criteria set57.

  • ICD-10: Mandatory inclusion of autonomic arousal symptoms54.

• Social Anxiety Specifier:

  • DSM-5: Includes Performance only specifier1819.

  • ICD-10: No performance-only specifier in F40.152.

• Mixed Anxiety-Depression:

  • DSM-5: No standalone Section II code (use Other Specified Anxiety Disorder)5859.

  • ICD-10: Standalone primary category F41.2