What are the DSM‑5 criteria for hypochondriasis (Illness Anxiety Disorder)?

DSM-5 Criteria for Illness Anxiety Disorder (Formerly Hypochondriasis)

In DSM-5, hypochondriasis was eliminated and replaced by two distinct diagnoses: Illness Anxiety Disorder (IAD) and Somatic Symptom Disorder (SSD), with the key distinction being the presence or absence of significant somatic symptoms. 1, 2, 3

Core Diagnostic Criteria for Illness Anxiety Disorder

Criterion A: Preoccupation with Having or Acquiring a Serious Illness

• The patient exhibits excessive preoccupation with having or acquiring a serious medical illness, despite minimal or absent somatic symptoms. 4, 3
• This preoccupation must be excessive and recurrent, representing pathological health anxiety rather than normative health concerns. 5

Criterion B: High Level of Health Anxiety

• The individual demonstrates a high level of anxiety about health, with heightened alarm about personal health status. 2, 3
• This anxiety is disproportionate to any actual medical risk or objective findings. 4

Criterion C: Excessive Health-Related Behaviors or Maladaptive Avoidance

• The patient engages in excessive health-related behaviors (e.g., repeatedly checking body for signs of illness, excessive medical consultations, reassurance-seeking). 6, 3
• OR exhibits maladaptive avoidance (e.g., avoiding medical appointments, hospitals, or health-related information). 6
• Research demonstrates that avoidance is a valid behavioral construct, with more severely avoidant patients showing higher symptom severity, functional impairment, and lower quality of life. 6

Criterion D: Duration

• The illness preoccupation must be present for at least 6 months. 4, 3
• The specific illness feared may change over this 6-month period. 3

Criterion E: Exclusionary Criteria

• The preoccupation is not better explained by another mental disorder such as Somatic Symptom Disorder, Panic Disorder, Generalized Anxiety Disorder, Body Dysmorphic Disorder, Obsessive-Compulsive Disorder, or Delusional Disorder (somatic type). 3

Specifiers for Care-Seeking Behavior

Care-seeking type: Medical care is frequently utilized. 1

Care-avoidant type: Medical care is rarely utilized. 1

Mixed type: The patient fluctuates between seeking and avoiding care (this is the most common presentation, occurring in 61% of IAD cases). 1

Key Distinction: IAD vs. Somatic Symptom Disorder

The critical differentiator is somatic symptom burden:

• IAD: Minimal or no somatic symptoms are present; the focus is on anxiety about potentially having a serious illness. 1, 2, 3
• SSD: Significant somatic symptoms are present and distressing, with excessive thoughts, feelings, or behaviors related to these symptoms. 1, 2, 3

Epidemiological Distribution

• Among patients with DSM-IV hypochondriasis, approximately 74% meet criteria for SSD and only 26% meet criteria for IAD under DSM-5. 2
• In health-anxious treatment-seeking samples, 45% meet SSD criteria, 47% meet IAD criteria, and 8% meet both. 1

Clinical Characteristics and Severity Differences

Patients with SSD demonstrate greater clinical severity compared to IAD:

• Higher health anxiety severity and somatic symptom burden. 1, 2
• More functional impairment and disability. 1
• Higher rates of comorbid disorders, particularly Major Depressive Disorder, Panic Disorder, and Agoraphobia. 1, 2
• Greater healthcare utilization, including more medical and psychologist visits. 1, 5

However, both IAD and SSD share similar core features:

• Comparable levels of hypochondriacal characteristics, illness behavior, somatic symptom attributions, and physical concerns. 2
• Similar response to Cognitive Behavioral Therapy (CBT). 2, 5

Diagnostic Reliability

IAD demonstrates excellent diagnostic reliability (kappa = 0.80), superior to DSM-IV hypochondriasis (kappa = 0.60). 1

Common Pitfalls and Clinical Considerations

Cultural Factors

• Somatic presentations predominate in non-Western cultures, potentially leading to underdiagnosis of IAD when DSM-5's emphasis on psychological worry is applied rigidly. 7
• Bilingual patients may emphasize somatic complaints in certain languages (e.g., Spanish) versus psychological symptoms in English. 8

Differential Diagnosis Challenges

• Rule out medical conditions that could explain the health concerns before diagnosing IAD. 3
• Distinguish from Generalized Anxiety Disorder: In GAD, worry is generalized across multiple life domains; in IAD, worry is specifically focused on health and illness. 8
• Distinguish from Panic Disorder: In panic disorder, anxiety centers on panic attacks themselves, not on having a serious underlying disease. 1
• Distinguish from Obsessive-Compulsive Disorder: While both may involve checking behaviors, OCD involves broader obsessions and compulsions beyond health concerns. 7

Personality Pathology

• Substantial comorbidity exists between personality pathology and IAD, particularly Avoidant and Dependent Personality Disorders. 9
• Personality traits of negative affectivity, detachment, and psychoticism are associated with greater functional impairment in hypochondriasis. 9

Treatment Implications

• Cognitive Behavioral Therapy (CBT) is the most effective treatment for IAD, with strong empirical support. 4, 3
• SSRIs are commonly prescribed medications for health anxiety. 10
• Poor follow-up rates are common (median 2 months in one study), highlighting the importance of engagement strategies. 10

Ongoing Diagnostic Controversies

The validity of splitting hypochondriasis into IAD and SSD remains debated:

• Some research suggests the distinction conveys little useful clinical information, as differences appear primarily related to severity rather than distinct pathophysiology. 2, 5
• The ICD-11 continues to classify hypochondriasis as an anxiety disorder, reflecting ongoing nosological uncertainty. 7
• Research using DSM-5 IAD criteria is still limited, and more validation studies are needed. 4