Illness Anxiety Disorder is an anxiety-based mental disorder characterized by persistent and excessive concern that one has, or will develop, a serious illness. The most striking feature of this condition is that, despite the absence of an objectively demonstrable disease, the individual misinterprets bodily sensations and experiences a constant perception of threat regarding their health status. Classified under Somatic Symptom and Related Disorders in the DSM-5, this disorder is the redefined form of the condition formerly referred to as “hypochondriasis.” Illness Anxiety Disorder typically emerges in an individual’s 20s or 30s and may follow a chronic course.
This disorder may affect not only the individual’s relationship with health services but also all areas of life. Reduced functioning, frequent visits to health institutions, tension in social relationships, and a marked decline in quality of life are commonly encountered. Individuals often consult multiple specialists and undergo repeated tests; however, even when results are normal, a significant reduction in anxiety levels is not observed.
Illness Anxiety Disorder DSM-5 Diagnostic Criteria
According to the DSM-5, the following criteria must be met in order to diagnose Illness Anxiety Disorder:
- The individual has a marked concern about having or acquiring a serious illness.
- Somatic symptoms are absent or, if present, are only mild; however, the individual’s health-related anxiety is excessive relative to this condition.
- Health-related anxiety causes a high level of anxiety, and the individual shapes health behaviors (e.g., repeatedly seeking medical evaluation or avoiding health information) according to this anxiety.
- The preoccupation with having an illness persists for at least 6 months; during this period, the specific illness feared may change.
- The symptoms are not better explained by another mental disorder (e.g., Somatic Symptom Disorder, Obsessive-Compulsive Disorder, Somatization Disorder, etc.).
The DSM-5 divides the disorder into two subtypes:
- Care-Seeking Type: The individual frequently visits physicians and undergoes numerous examinations.
- Care-Avoidant Type: The individual avoids health institutions due to fear of possibly having an illness.
Symptoms of Illness Anxiety Disorder
In individuals with Illness Anxiety Disorder, the following symptoms may be observed:
- Interpreting normal bodily sensations as signs of illness (e.g., perceiving one’s heartbeat as evidence of heart disease),
- Distrust in medical test results,
- Searching the internet for health-related information (cyberchondria),
- Not being reassured despite comforting explanations from close others,
- Generating persistent thoughts about the possibility of becoming ill,
- Experiencing intense anxiety without prominent physical findings,
- Organizing daily life around health-related thoughts.
These symptoms impair both the individual’s psychological stability and their social and occupational functioning. Over time, depressive symptoms and a decrease in overall life satisfaction may emerge.
Causes (Etiology) of Illness Anxiety Disorder
A biopsychosocial model is taken as the basis for the development of Illness Anxiety Disorder. Rather than a single cause, the combination of biological predispositions, psychological learning processes, and environmental factors plays a role in the emergence of the disorder.
1. Genetic and Neurobiological Factors:
- It is more frequently observed in individuals with a family history of anxiety disorders or somatic complaint disorders.
- It has been suggested that dysregulation in serotonin and norepinephrine systems may contribute to the disorder by affecting anxiety regulation.
- Functional brain imaging studies have shown increased activity in the anterior cingulate cortex and the insula in individuals with illness anxiety (Starcevic, 2014; Barsky & Ahern, 2004).
2. Learned Behaviors and Cognitive Tendencies:
- Exposure during childhood to parental behaviors excessively focused on illness,
- Experiencing a serious illness at an early age or witnessing a fatal illness in close surroundings,
- Negative automatic thoughts (e.g., “If I have chest pain, I must be having a heart attack”) and selective attention (focusing only on bodily sensations).
3. Cultural and Social Factors:
- An overload of illness-related information through the media,
- Frequent use of medical terminology in daily life,
- A tendency to undergo continuous medical testing due to easy access to health services.
Risk Factors for Illness Anxiety Disorder
- Having previously been diagnosed with an anxiety disorder or depression,
- Recent medical events or illnesses,
- Traumatic life experiences (e.g., loss of a parent, abuse),
- Growing up with parents who exhibit high levels of health anxiety,
- Ambiguous or insufficient explanations provided by physicians.
Awareness of these factors may facilitate early diagnosis, particularly in primary care settings.
How Is It Diagnosed?
The diagnostic process involves a detailed interview conducted by a psychiatrist or clinical psychologist. During DSM-5-based assessment, the following elements are taken into account:
- The intensity of health-related anxiety,
- The presence or absence of somatic symptoms,
- The functional impact of anxiety on daily life,
- The relationship with the health care system (excessive utilization or avoidance behaviors),
- In differential diagnosis, conditions such as Somatic Symptom Disorder, Generalized Anxiety Disorder, Obsessive-Compulsive Disorder, and Major Depressive Disorder must be ruled out.
If there is suspicion of an organic disease, only necessary tests should be performed, and repeated unnecessary investigations should be avoided.
Treatment of Illness Anxiety Disorder
Illness Anxiety Disorder is a mental disorder that can respond positively to treatment with appropriate approaches. The treatment process should be planned individually and carried out in a multidimensional manner. The main treatment methods are listed below:
1. Psychotherapy
Cognitive Behavioral Therapy (CBT) is the primary treatment method for this disorder. Clinical studies have shown that CBT both reduces anxiety levels and decreases reassurance-seeking behaviors (Hedman et al., 2016).
During CBT:
- Misinterpretation of bodily sensations is addressed,
- Cognitive distortions are corrected,
- Coping skills for avoidance and checking behaviors are developed,
- Exposure and response prevention (ERP) techniques may be utilized.
2. Pharmacotherapy
- SSRI antidepressants are effective in reducing anxiety symptoms.
- If depressive symptoms are present, pharmacotherapy is particularly recommended.
- Pharmacotherapy generally yields better outcomes when combined with psychotherapy.
3. Psychoeducation
During treatment, the aim is to provide the patient with accurate information about the nature, course, and treatment process of the disorder. In addition, informing family members may help prevent behaviors that reinforce excessive reassurance or avoidance.
Effects on Daily Life
Individuals with Illness Anxiety Disorder may experience severe functional impairments in daily life. Due to persistent health-focused thoughts:
- Work performance may decline,
- Social relationships may weaken,
- Daily activities may be restricted (e.g., avoiding exercise),
- Sleep and eating patterns may deteriorate,
- The economic burden of unnecessary medical testing may increase.
Over time, depression and social isolation may develop. Therefore, if left untreated, serious deterioration in the individual’s quality of life may occur.
Illness Anxiety Disorder is a common yet often undiagnosed mental disorder that highlights the complex interaction between body and mind. With early diagnosis and appropriate treatment, the individual’s quality of life may be significantly improved. The combined use of psychoeducation, CBT, and, when necessary, pharmacotherapy may yield positive long-term outcomes. Awareness of this disorder among health professionals can pave the way for important improvements at both the individual and system levels.