Placebo: a brief updated review

Area of Science:

• Medical Science
• Clinical Psychology
• Pharmacology

Background:

• The placebo and nocebo effects are well-documented phenomena across diverse medical conditions.
• These effects manifest with various interventions, including oral medications, manual therapies, surgery, and invasive procedures.
• The ethical considerations of using placebos in clinical trials are actively debated.

Purpose of the Study:

• To offer an updated overview of placebo/nocebo effects.
• To explore the potential applications of placebos in clinical practice.
• To serve as an introductory resource for further literature exploration.

Main Methods:

• Literature review of findings published in the last two decades.
• Analysis of the psycho-neurobiological underpinnings of placebo effects.
• Examination of factors influencing placebo response, including the doctor-patient relationship.

Main Results:

• Placebo effects can mimic drug actions pharmacokinetically and pharmacodynamically, and are associated with adverse nocebo effects.
• Placebos can modulate the efficacy of concomitant drug treatments.
• The doctor-patient relationship is a significant factor influencing placebo response, alongside placebo-specific characteristics.

Conclusions:

• The psycho-neurobiological basis of placebo is increasingly understood, though further research is necessary.
• Clinical placebo effects typically range from weak to moderate in intensity.
• Placebo should be considered a therapeutic option in clinical practice, either alone or adjunctively, and its use merits regulatory guidance from health authorities like European ones to enhance patient care.