A pessimistic outlook can be unknowingly detrimental to your health outcomes, as personalities predisposed to negativity may experience the nocebo effect more acutely.

Source: https://www.forbes.com/sites/traversmark/2023/12/10/a-psychologist-explains-the-nocebo-effect-and-how-to-avoid-it/

Health anxiety can also be complicated by the nocebo effect, which operates in the opposite direction of the more familiar placebo effect.

Source: https://www.theguardian.com/commentisfree/2023/oct/29/health-anxiety-can-be-all-consuming-accepting-uncertainty-is-an-important-step