Hypochondriasis Risk Increases with Genetic Relatedness in Large Cohort

Hypochondriasis, characterized by a distressing preoccupation with having a serious illness, imposes a significant burden on patients and the healthcare system. While the International Classification of Diseases 11th Revision (ICD-11) now groups this condition with obsessive-compulsive and related disorders, its etiology remains poorly understood compared to other psychiatric phenotypes [1, 2]. Clinical observations show that health-related anxieties often emerge in childhood and persist into adulthood, frequently co-occurring with depression and generalized anxiety [3, 4]. Research into transgenerational transmission suggests children may acquire these fears through vicarious learning (the process of acquiring a fear response by observing another person's reaction to a stimulus) or parental modeling of illness behaviors [5]. A population-based cohort study of 5,809,325 individuals recently clarified the role of genetics, finding that full siblings of patients with hypochondriasis have a 9.5-fold increased risk (95% CI, 5.1 to 17.5) of receiving the same diagnosis [6]. This risk follows a gradient of genetic relatedness, with hazard ratios of 5.6 (95% CI, 2.1 to 14.9) for half siblings and 2.6 (95% CI, 1.4 to 4.9) for cousins, indicating that the disorder is both familial and likely heritable [6].