Table 3.

Operational definition suggested for the initial stage of treatment‐resistant depression (TRD)

Operational criteria	Quality of evidence	Level of agreement
TRD should be defined by the failure to achieve response to two adequately dosed and evidence supported trials of antidepressant medications	GRADE‐high	83%, 10/12
Nonresponse should be defined as less than 50% symptom reduction	GRADE‐high	83%, 10/12
The minimal length of antidepressants trial should be defined as 4–6 weeks	GRADE‐high	83%, 10/12

Abbreviation: GRADE, grading, assessment, development, and evaluation.