In medicine, the word remission refers to a temporary or permanent lessening or complete absence of disease symptoms.
One commonly accepted definition of remission used in depression research studies is having a score of seven or below on the HAM-D-17 (17-item Hamilton Rating Scale for Depression).
Complete and sustained remission of symptoms is the ultimate goal of depression treatment.
In the STAR*D (Sequenced Treatment Alternatives to Relieve Depression) study, 70% of patients achieved complete remission of their symptoms by the time they reached their fourth level of treatment. A level of treatment was considered to be a change in their medication regimen, either switching to a different antidepressant or adding an additional one.
"Questions and Answers about the NIMH Sequenced Treatment Alternatives to Relieve Depression (STAR*D) Study — All Medication Levels." National Institute of Mental Health. November 2006. National Institutes of Health. Accessed: June 28, 2012.