Polygenic risk scores predict response to ECT for major depressive disorder

A polygenic liability for major depressive disorder and bipolar disorder contributes to improvements following electroconvulsive therapy (ECT), reports a study. This provides evidence of a genetic factor for clinical response to ECT.

“These liabilities may be considered along with clinical predictors in future prediction models of ECT outcomes,” said the researchers, who invited patients with least one treatment series recorded in the Swedish National Quality Register for ECT between 2013 and 2017 to provide a blood sample for genotyping.

A total of 2,320 individuals (median age 51 years, 62.8 percent women) who had received an ECT series for a major depressive disorder (77.1 percent unipolar depression), who had a registered treatment outcome, and whose polygenic risk scores (PRSs) could be calculated were included.

The effect of PRS on Clinical Global Impressions improvement scale (CGI-I) score after each ECT series was estimated using ordinal logistic regression.

Greater PRS for major depressive disorder significantly correlated with less improvement on the CGI-I (odds ratio [OR] per standard deviation [SD], 0.89, 95 percent confidence interval [CI], 0.82‒0.96; R²=0.004), while greater PRS for bipolar disorder correlated with better improvement on the CGI-I (OR per SD, 1.14, 95 percent CI, 1.05‒1.23; R²=0.005) after ECT.

Of note, PRS for schizophrenia did not correlate with improvement.

The results were similar in an overlapping sample (n=1,207) with data on response and remission obtained from the self-rated version of the Montgomery-Åsberg Depression Rating Scale, except that PRS for schizophrenia also correlated with remission.

“Identifying biomarkers associated with response to electroconvulsive therapy (ECT) may aid clinical decisions,” they noted.