Swedish researchers have found that believing in the value of antidepressant medication appears to influence their benefits.
Experts believe the findings suggest that the way in which the treatment is described to the patient can be as important as the treatment itself. Moreover, the discovery may help to explain why selective serotonin reuptake inhibitors (SSRIs) work for some individuals but not for others.
Uppsala University researchers said that clinicians and researchers have debated the benefits of SSRIs. Clinicians argue that SSRIs may lack specific therapeutic properties and that their beneficial effects observed in clinical trials could be explained by different expectancies in the drug and placebo groups.
Even in a in a double-blind study in which participants are not informed if they are taking a placebo or an antidepressant, the participant may come to realize that he or she has been given the drug instead of placebo because of the experienced side effects. This knowledge may in turn result in increased expectations of improvement and a better effect is reported.
Researchers at Uppsala University’s Department of Psychology discovered that when participants were informed that they were given an antidepressant, they reported better symptom relief. Researchers used the SSRI escitalopram (Lexapro) to demonstrate the considerably better effects when a participant was given with correct as compared to incorrect verbal information.
Study results appear in the journalÂ EBioMedicine.
In the randomized study, all patients with social anxiety disorder were treated with the same dosage of escitalopram for nine weeks, but only one group was correctly informed about the drug and its effectiveness.
The other group was led to believe they were treated with a so-called “active placebo with similar side effects as the SSRI but no clinical effect.
“Our results show that the number of responders was three 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 author Dr. Vanda Faria.
Apparently, the knowledge or belief that antidepressant will be successful results in brain changes; MRI neuroimaging showed that the SSRI had different effects on brain activity when associated with expectations of improvement or not.
There were differences between the two groups in activations of the posterior cingulate cortex and the coupling between this region and the amygdala, the small brain structure central to fear and anxiety.
“This may reflect an interaction between cognition and emotion as the brain changes differently with medication pending on the patient’s expectancies,” said co-author Dr. Malin Gingnell.
The results suggest a marked placebo component related to expectancies in SSRI treatment, underscoring the importance of the communication between prescriber and patient.
“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 Dr. Tomas Furmark, who led the study.
Source: Uppsala University