Harnessing the Placebo Effect: How Expectations Shape Response to Treatment


April 21, 2015
Harnessing the Placebo Effect: How Expectations Shape Response to Treatment
Dr. David Prescott – Acadia Hospital

The Placebo Response: Psychologists and other health professionals have long known that expectations play an important role in how people respond to any type of health treatment.  This is clearly illustrated by what scientists call the placebo response.  Some people, if given a harmless pill that they believe is a real medicine, show improvement even though they never received an actual drug.  It appears that people’s expectations that they would improve had a powerful effect.

How Powerful is the Placebo Response? For many years, scientists and researchers considered the placebo response a nuisance that had to be controlled in research studies.  But, more recently, researchers have begun to investigate how placebo responses work.  Studies that examine brain activity have shown that people who thought they were getting medicine to help reduce pain, even though they were getting a placebo, had less brain activity in regions of the brain associated with pain messages. 
Similarly, patients with depression who thought they were getting a medicine to help with symptoms, but who actually were receiving placebo, showed changes in brain centers associated with rewards and motivation.  Studies like this suggest that people’s brain chemistry actually changes when they believe that they are going to get better. 

How Does the Placebo Response Work? One current debate is whether the placebo response is the result of conscious beliefs or unconscious expectations.  That is, can people improve simply be developing positive beliefs about improvement, or is the effect more unconscious?  It may be that people only improve when they go through the act of taking a medication that they believe will help.  Or, psychologists and doctors may be able to find ways to help patients develop positive expectations about treatment that are just as powerful as giving them a ‘sugar pill.’ 

What are the Implications of the Placebo Response for Health and Mental Health Treatment?  The placebo response reminds us of the interconnectedness of the mind and the body.  As we seek better understanding of how our beliefs and expectations influence our ability to heal, our knowledge about the placebo response suggests that:
  • Healthcare Providers can Help Patients by Setting Positive (Yet Realistic) Expectations for Treatment:  The placebo response reminds healthcare providers that promoting realistic hope may have helpful properties beyond the identified treatment given to a patient.  Some research suggests that providers who were warm, caring and empathic elicited stronger placebo responses than those who are not.
  • Beliefs and Expectations for Improvement Appears to Help: While the effect may be modest, there is support for the idea that expecting to improve, be it from depression or Parkinson’s Disease, makes it more likely that you will improve. 
  • Mental, as well as physical, interventions help psychological and physical conditions. Psychologists and other mental health professionals have long known that mental interventions, for example psychotherapy, can help with psychological conditions.  However, interventions with the mind to help heal the body appear to be quite powerful.  Treatments for mental and physical disorders appear to be moving away from the mindset of focusing on either physical or cognitive interventions.  Rather, both approaches are viewed as having a role. 
For More Information:  Visit American Psychological Association Website www.apa.org