[Nocebo, informed consent and doctor-patient communication]

Area of Science:

• Psychiatry
• Neuroscience
• Medical Ethics

Background:

• Nocebo effects, triggered by conditioning, observation, and expectations, contribute significantly to medical treatment side effects.
• These effects are particularly influenced by risk information provided during informed consent processes.
• Side effects and drop-outs are observed even in placebo groups within clinical trials, especially in neurology and psychiatry.

Purpose of the Study:

• To investigate the neurobiological mechanisms underlying nocebo effects, specifically nocebo-induced hyperalgesia.
• To identify brain regions and neurochemical systems involved in nocebo responses.
• To explore strategies for minimizing harm from risk information during informed consent.

Main Methods:

• Experimental investigation of neurobiological mechanisms, including functional imaging.
• Analysis of changes in dopamine, endorphin, and cholecystokinin systems.
• Comparative studies of patient groups receiving standard versus modified medical information.

Main Results:

• Specific brain regions and neurochemical systems (dopamine, endorphin, cholecystokinin) are implicated in nocebo-induced hyperalgesia.
• Nocebo effects are specific to the information provided and can manifest as the exact symptoms warned about.
• Risk information can be less damaging when presented without unnecessary repetition, with misunderstandings resolved, and alongside positive treatment aspects.

Conclusions:

• Informed consent is crucial, but careful communication of risks is essential to prevent nocebo effects.
• A trusting doctor-patient relationship is the most effective safeguard against harm from risk information.
• Lack of awareness or countermeasures for nocebo effects poses a serious threat and may constitute medical malpractice.