Commentary: Harm, Truth, and the Nocebo Effect.

Nocebo effects occur when an individual experiences undesirable physiological reactions caused by doxastic states that are not a treatment's core or characteristic features.1 As Scott Gelfand2 points out, there are numerous studies that have shown that the disclosure of a treatment's side effects to a patient increases the risk of the side effects. From an ethical point of view, nocebo effects caused by the disclosures of side effects present a challenging problem. On the one hand, clinicians' duty to inform patients of the consequences (including possible side effects) of their treatments is critical in ensuring that patients' autonomy is respected. Patients cannot act autonomously if relevant information is withheld from them (without their consent, perhaps). On the other hand, clinicians also ought to minimize harm to patients.