Impact of Dopamine and Placebo on SSRIs

Levels of dopamine and the placebo effect may determine if treatment with SSRIs (selective serotonin reuptake inhibitors) would work for patients with social anxieties as per a study at the Uppsala University, published in Translational Psychiatry. The study shows the drug effect was four times higher for patients with high expectations of the medication as compared with patients with low expectations.

The SSRIs work by influencing the levels of serotonin in the brain – an effective medication for treating depression and anxiety. However, the study found that dopamine also greatly has an impact on the improvements.

SSRIs and Efficacy

It is evident from previous studies that the placebo effect has a major impact on the anti-anxiety effect of the SSRI drug escitalopram. The present study, however, related the improved drug (SSRI) efficacy to dopamine rather than to the serotonin transporters.

“The results showed that almost four times as many patients responded to the treatment when correct information about the drug was given. This is consistent with previous research showing that expectations affect treatment outcome,” says researcher Olof Hjorth, Uppsala University.

In addition, when using the positron emission tomography (PET) brain scan, it was shown that the SSRI drug had the same effect on serotonin and blocked about 80% of serotonin transporters in study groups.

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“The results indicate that positive expectations arising in the relationship between doctor and patient affect dopamine and enhance the effect of SSRI treatment,” says Professor Tomas Furmark, who led the study.

Source-Medindia