Which disorder is marked by the patients’ inability to interpret bodily symptoms appropriately?

Illness anxiety disorder is characterized by an individual's excessive preoccupation with having or acquiring a serious illness, despite the absence of significant physical symptoms. Patients with this disorder tend to misinterpret normal bodily sensations as indicative of severe medical conditions, leading to heightened anxiety and distress. Their inability to accurately interpret bodily symptoms can manifest as frequent health-related worries and behaviors, such as repeatedly seeking medical evaluations or engaging in health rituals.

This disorder is distinct from other options. Capgras syndrome involves a delusional belief that a familiar person has been replaced by an identical impostor, which is unrelated to bodily symptom interpretation. Folie-à-deux, or shared psychotic disorder, entails a shared delusion between two closely associated individuals, without a focus on bodily symptoms. Ganser's syndrome is characterized by nonsensical or approximate answers to questions, often in the context of a mental health crisis or extreme stress, but also does not primarily involve misinterpretation of bodily sensations. Thus, the hallmark of illness anxiety disorder is the persistent and inappropriate interpretation of bodily symptoms as indicators of illness, making it the correct choice.