Two Gene Variations Predict Citalopram Response
Good outcome more likely in patients who carry a newly and a previously identified marker
MONDAY, Aug. 13 (HealthDay News) -- A newly identified marker -- a variation in the GRIK4 gene -- may help identify depressed patients who are more likely to respond to citalopram, researchers report in the August issue of the American Journal of Psychiatry.
Silvia Paddock, Ph.D., of the Karolinska Institute in Stockholm, Sweden, and colleagues performed a new analysis of data from the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study and studied the association between treatment response and 768 markers that were genotyped in the full set of 1,816 eligible patients.
In addition to a previously identified marker in the serotonin 2A receptor gene, HTR2A, the researchers identified a marker in the GRIK4 gene that codes for the kainic acid-type glutamate receptor KA1. The investigators found that patients who carried both of these marker alleles were 23 percent more likely to respond to citalopram than patients who did not carry either of these alleles.
"These results suggest a role for glutamate as well as for serotonin in modulating the response to at least one selective serotonin reuptake inhibitor, citalopram," states the author of an accompanying editorial. "They also raise the exciting possibility of pretreatment identification of patients more or less likely to experience response to a given medication."