Expectations Can Affect Treatment Efficacy
A 2017 article by Vanda Faria and colleagues in the journal EBioMedicine reports that when patients with social anxiety disorder were told they were being treated with an active drug, they had a response rate three times higher than patients who were given the same drug but told it was an inactive placebo. The researchers suggest that the way treatments are presented to patients affects whether they work.
In the study by Faria and colleagues, patients with social anxiety were given the selective serotonin reuptake inhibitor (SSRI) antidepressant escitalopram for nine weeks. Some were told they had received escitalopram, while some were told they had received a placebo. Not only did those who were told they were taking escitalopram see greater reductions in their anxiety, they also showed more connectivity between the posterior cingulate and the amygdala, a region that is crucial to mediating anxiety.
This finding is in line with other research that has found that patients’ thoughts and expectations during treatment can affect the efficacy of that treatment.
Researcher Isaac Marks found that patients with obsessive compulsive disorder (OCD) with fear of contamination who were told to avoid things they feared, such as touching a toilet seat, did not fare any better than those taking placebo pills. However, those taking SSRIs who tried new behaviors like touching a toilet seat learned that they could do so without a major fear response, and their phobias improved.
Several studies have shown that expectations of antidepressant efficacy have a big effect on whether patients with unipolar depression improve after beginning treatment with SSRIs. Bret R. Rutherford and colleagues reviewed findings on expectancy in major depressive disorder in a 2010 article in the journal Current Psychiatry Review.
When patients are presented with a drug and encouraged to believe it will work, they may gain the confidence to try out new behaviors or ways of looking at things, whether that means exploring new social situations for someone with social anxiety, or feeling hopeful and breaking the habit of negative rumination for someone with depression. As the study by Faria and colleagues shows, expectations can even change patterns of brain connectivity.
Studies of repetitive transcranial magnetic stimulation (rTMS), in which electromagnets placed near the scalp stimulate electrical impulses in the brain, have shown that patients with depression who engage in positive thoughts and conversations with their rTMS provider during the stimulation improve more than those who sit passively. If a patient engages in their habitual negative ruminations during rTMS, these might even be cemented by the rTMS-induced release of glutamate and brain-derived neurotrophic factor (BDNF), which are both involved in learning and memory processes and what has been called experience-dependent neuroplasticity.
Thus, a patient’s thoughts and outlook during treatment may be important to the therapeutic outcomes achieved. While expectations may not be sufficient to produce an effect on their own, it does seem that thoughts and behaviors can improve a treatment’s efficacy.
