Adults with Major Depressive Disorder who report blunted emotion that is evidenced by responses on the Oxford Depression Questionnaire will add lumateparone to their current treatment once daily for 8 weeks. Primary endpoint will be change fom baseline to week 8 on the Oxford Depression Questionnaire (ODQ). Secondary endpoints will be change from baseline to week 8 on CGI-I and CGI-S as well as change from baseline to week 8 on quality of life as measured by Q-LES-Q-SF.
