Course and Prognosis
Illness Anxiety Disorder can occur at any age but there may be a history of health-related concerns dating back to adolescence upon careful medical history taking. Risk of Hypochondriasis does not appear to be influenced by education levels or income. Very little information is available regarding the longitudinal course of the illness. The few available studies show that over half of people with Illness Anxiety Disorder will experience persisting and functionally impairing symptoms over time without appropriate intervention. While spontaneous resolution of symptoms does occur in a minority of individuals, treatment should be considered for all because spontaneous resolution occurs unpredictably (i.e., no clear predictive factors have yet been identified).
Differential Diagnosis (or, When Is It Really Hypochondriasis?)
Prior to interviewing the patient, it is good practice to review the case records and investigations of the patient to date (if available), to help ensure that medical disorders have not been overlooked and in order to help prepare one’s approach towards the patient. Do not rely on statements from other clinicians that the basis of the patient’s presentation is clearly "psychiatric" in nature. Keep in mind that some medical conditions can have a psychiatric presentation—e.g., multiple sclerosis and (para)thyroid dysfunction. Having considered this beforehand, the clinician is in a position to provide appropriate firm reassurance and avoid succumbing to requests for unnecessary investigations, which can serve to perpetuate Illness Anxiety Disorder rather than to alleviate it. Even if Illness Anxiety Disorder is confirmed, periodically review the patient’s symptoms and presentation in the event that medical conditions have indeed developed.
In addition to considering the possibility of underlying medical disorders, it is important also to differentiate Illness Anxiety Disorder from these other psychiatric conditions:
- • Somatic Symptoms Disorder. This DSM-5 term encompasses individuals formerly diagnosed with Somatization Disorder. The hallmark of Somatic Symptoms Disorder is excessive focus on a plethora of bodily symptoms (e.g., aches, pains, rumblings) that often change over time; the individual will fixate on talking about these, and their impact on day-to-day life, rather than expressing concern that a specific disorder has been missed. The key to differentiating these conditions lies partly in sensitive exploration of the patient’s experiences and whether they have any particular worries about what the cause of the symptoms might be.
- • Chronic Fatigue Disorder. This is not a psychiatric disorder as such but shares parallels with Somatic Symptoms Disorder above, and can be confused for Illness Anxiety Disorder. Core features are joint pain, muscle pain, lymph node tenderness, headache, sore throat, poor sleep, general malaise persisting >24 hours after exertion, and subjective memory problems (four or more of these required for diagnosis).
- • Generalized Anxiety Disorder. People with this condition have excessive anxieties about a variety of events and activities occurring as part of day-to-day life. Examples include pervasive and disproportionate concerns about job responsibilities, health and finances, and the health of family members. The clinician should try to differentiate between patient concerns over their perceived physical health as it relates to having
or obtaining an illness versus concerns over work, school, relationships, etc.
- • Social Anxiety Disorder (or Social Phobia). Individuals fear and avoid situations when they may be exposed to the scrutiny of others (public speaking, being in bars/restaurants, meeting new people). They fear negative evaluation by others. Exposure to given situations nearly always provokes anxiety and/or avoidance. The underlying concerns relate to external cues rather than internal somatic experiences.
- • Panic Disorder. The distinguishing feature of Panic Disorder as compared to Illness Anxiety Disorder is the occurrence of discrete periods (abrupt onset, peaking within 10 minutes) of intense fear and/or discomfort and physiological sensations (e.g., tachycardia, shallow rapid breathing leading, sweating, dizziness). These discrete events may at the time be perceived to be a medically significant event (e.g., a heart attack). After one or more panic episodes, the patient tends to worry about panic attacks recurring and associated embarrassment plus loss of control, rather than seeking medical attention because they believe specific medical disorders have been missed.
- • Body Dysmorphic Disorder (BDD). Here, the individual is preoccupied with the belief that he or she has one or more defects in their outward physical appearance rather than having a labeled medical condition. In Illness Anxiety Disorder, sufferers are worried that an internal disorder is not “noticeable” to others (i.e., is being overlooked), while in BDD, subjects believe their perceived deficits are very noticeable to others and consequently attempt to avoid exposure. Excessive checking and reassurance seeking nonetheless commonly occur in both conditions.
- • Obsessive Compulsive Disorder (OCD). There are many parallels between Illness Anxiety Disorder and OCD: both involve recurrent intrusive thoughts and compulsions undertaken in a rigid way and/or in response to these thoughts. A diagnosis of OCD is more appropriate when the nature of obsessions and compulsions generalize to other domains besides the belief that there is an unrecognized serious medical disorder. It can be helpful to use the Yale-Brown Obsessive Compulsive Scale (YBOCS) symptom checklist to help detect the presence of symptom types more likely to be due to OCD (see OCD chapter).
The Whiteley Index is a 14-item self-complete questionnaire, which poses a variety of questions in binary form (“no” or “yes”). A total score of 5 or more on the Whiteley Index is strongly suggestive of Hypochondriasis. This is quite a useful instrument for quick screening.
The Hypochondriasis Yale-Brown Obsessive Compulsive Scale Modified (H-YBOCS-M: Appendix C) is a clinician-administered scale and is recommended for tracking response to treatment. It considers illness thoughts / worries, illness-related behaviors, and illness-related unhealthy avoidance (i.e., three domains rather than the two in the original YBOCS used for OCD). Within each domain there are six questions, each scoring 0-4 with higher scores indicating greater severity. This generates a total score (range 0-72) and three sub-scale scores (each range 0-24). There is an additional item in the H-YBOCS-M quantifying insight (0-4) though this is not utilized in the summary scores. As a rough guide, total Hypochondriasis severity scores can be categorized as: no Hypochondriasis (0), minimal Hypochondriasis (1-12), moderate Hypochondriasis (13-41), severe Hypochondriasis (42-56), and extreme Hypochondriasis (57-72). We recommend that treatment response be defined as a 35% or greater reduction in total severity score as this has been shown to be an indicator of treatment response in clinical research trials of similar conditions.