Patient Perceptions Affect Antidepressant Efficacy

Many patients are prescribed selective serotonin reuptake inhibitors (SSRIs) to treat depression and anxiety; however, the efficacy of these drugs has been questioned, in part because of their delayed effect on symptoms.

A new study published by EBioMedicine suggests that the way SSRIs are described to patients may influence their efficacy in managing symptoms.

It has been debated whether SSRIs have the therapeutic properties necessary to treat patients and whether its effects observed in clinical testing could be related to different perceptions of the drugs, according to the authors.

In blind clinical trials, patients may experience side effects from the drugs and conclude they are receiving the treatment. However, the authors report that it has yet to be discovered how much perception affects the efficacy of SSRIs.

In the new study, the authors investigated patient outcomes for those given correct information about escitalopram, an SSRI, compared with those who receive incorrect information.

Patients with social anxiety disorder were treated with the same dose of the drug for 9 weeks, but 1 cohort received correct information about the efficacy of the drug. The other cohort was told they were taking an active placebo, which elicits similar side effects but without clinical benefits, according to the authors.

“Our results show that the number of responders was 3 times higher when correct information was given than when patients thought they were treated with an ineffective active placebo, even though the pharmacological treatment was identical,” said study author Vanda Faria, PhD.

Additionally, imaging tests showed that the SSRI changed brain activity based on whether the patients expected to see improvements or not. The authors discovered differences between the activation of the posterior cingulate cortex and the coupling between the region and the amygdala among patients, according to the study.

“This may reflect an interaction between cognition and emotion as the brain changes differently with medication pending on the patient’s expectancies,” said study co-author Malin Gingnell, MD.

These results suggest that the efficacy of SSRIs may be swayed by expectations of the drugs. The authors note that the findings highlight the importance of patient-prescriber communication, according to the study.

“We don’t think SSRIs are ineffective or lack therapeutic properties for anxiety but our results suggest that the presentation of the treatment may be as important as the treatment itself,” said lead researcher Tomas Furmark, who led the study.