Table 3.

Treatment strategies for partial or non-response to initial treatment

Guideline	1st-line treatment	Next intervention
Korean Medication Algorithm Project for Depressive Disorder 2017 (nonpsychotic depression)	Non-response: Switching AD, Adding AD, Adding AAP Partial response: Adding AD, Adding AAP	Non-response: Adding AUG Partial response: Switching AD, Adding AUG
Korean Medication Algorithm Project for Depressive Disorder 2017 (psychotic depression)	Switching AAP, Adding AD, Switching AD	Adding AAP, Adding AUG, Adding TAP
American Psychiatric Association Practice Guideline for the Treatment of Patients with Major Depressive Disorder, Third Edition	Optimizing the initial treatment Changing to a different treatment Augmenting and Combining treatment	-
Canadian Network for Mood and Anxiety Treatments	Switching to a second-line or third-line antidepressant Switching to antidepressant with superior efficacy Adding an adjunctive medication (aripiprazole, quetiapine, risperidone)	Second-line adjunctive medications: brexpiprazole, bupropion, lithium, mirtazapine, modafinil, olanzapine, triiodothyronine Third-line adjunctive medications: TCAs, ziprasidone, methylphenidate, lisdexamfetamine
National Institute for Health and Clinical Excellence	Nonresponse: increase the dose of initial AD, switch to another AD Partial response: switch to another AD	-
Texas Medication Algorithm Project	Nonpsychotic: augmenting another agent, switching to another AD, combination treatment, MAOI, TCA, TCA+lithium Psychotic: TCA or SNRI combination with AP, lithium augmentation, switch to another AP	-
World Federation of Societies of Biological Psychiatry	Switching from an SSRI to venlafaxine or tranylcypromine Combination of an SSRI with an inhibitor of presynaptic autoreceptors (e.g., mirtazapine) Adding lithium to ongoing antidepressant Augmenting thyroid hormones Augmenting quetiapine or aripiprazole	-
Royal Australian and New Zealand College of Psychiatrists clinical practice guidelines for mood disorders	Combine pharmacotherapy and psychological therapy Increase dose of antidepressant medication Augment antidepressant medication with lithium and/or antipsychotic medication Combine antidepressants rTMS	-

AAP, atypical antipsychotic agent; AD, antidepressant; AP, antipsychotic agent; AUG, other augmenting medications (lithium, anticonvulsants, buspirone, pindolol, psychostimulant, ketamine, thyroid hormone, etc); MAOI, monoamine oxidase inhibitor; SNRI, serotonin-norepinephrine reuptake inhibitor; SSRI, selective serotonin reuptake inhibitor; TAP, typical antipsychotic agent; TCA, tricyclic antidepressant; rTMS, repetitive transcranial magnetic stimulation.