Avoidance in hypochondriasis.

Area of Science:

• Psychiatry
• Clinical Psychology
• Behavioral Science

Background:

• The DSM-5 introduced illness anxiety disorder, incorporating avoidance as a behavioral response to illness fears.
• Prior diagnostic criteria for hypochondriasis lacked an explicit focus on maladaptive avoidance.
• Empirical support for maladaptive avoidance as a necessary or useful diagnostic criterion is limited.

Purpose of the Study:

• To investigate the empirical validity of maladaptive avoidance as a diagnostic criterion for hypochondriasis.
• To determine if avoidance is a useful indicator in the diagnosis of hypochondriasis.
• To compare the fit of different statistical models in assessing avoidance.

Main Methods:

• 195 individuals meeting DSM-IV hypochondriasis criteria were assessed using structured interviews and self-report measures.
• Maladaptive avoidance was measured using the Hypochondriasis - Yale Brown Obsessive Compulsive Scale - Modified (HYP-YBC-MOD) subscale.
• Continuous latent trait, categorical latent class, and hybrid factor mixture models were compared to evaluate avoidance's utility.

Main Results:

• A two-class factor mixture model provided the best fit for the data.
• Class 1 (n=147) showed higher avoidance severity than Class 2 (n=48).
• The more avoidant group reported greater hypochondriacal symptom severity, functional impairment, anxiety, and lower quality of life.

Conclusions:

• Avoidance appears to be a valid behavioral construct in the context of hypochondriasis.
• These findings support the inclusion of avoidance as a useful component in the DSM-5 diagnosis of illness anxiety disorder.
• The results have implications for understanding and diagnosing somatic symptom disorder.