Researchers have identified a positron emission tomography imaging agent that could identify the patients that are more likely to benefit from a drug designed to treat major depressive disorder, according to a study published this month in The Journal of Nuclear Medicine.
The C-DASB tracer targets a protein, 5-HTT, found in the part of a person’s brain that is responsible for emotional processing, called the amygdala. Escitalopram, a selective serotonin reuptake inhibitor, is indicated for people with depression, but it doesn’t work for all patients. Scanning a person’s brain to measure their 5-HTT level could help doctors determine if a patient will benefit from treatment with escitalopram, the researchers reported.
“MDD is a heterogeneous disorder, which makes it extremely difficult to treat effectively,” lead author Mala Ananth, of Stony Brook University, said in prepared remarks. “Optimizing treatment is challenging and is performed by trial and error, which could result in weeks of ineffective treatment, placing a burden on patients.”
The study involved 31 healthy individuals and 26 MDD patients who were not taking medication prior to the study’s launch. All study participants received a PET scan using C-DASB and people in the MDD group received eight weeks of therapy with escitalopram.
“Using PET, we quantified the protein target of SSRIs, the serotonin transporter 5-HTT. Our results indicate that patients who found relief following escitalopram treatment had less 5-HTT protein before treatment began,” Ananth explained.
“Psychiatry currently has no objective markers to determine whether a treatment will be effective. PET imaging can fill that gap and can be used to quantify biological features that indicate a successful course of treatment. Further, these features shed light on the neurobiology of MDD needed to develop novel and more targeted therapeutics.” the researcher added.