When is a patient with Major Depressive Disorder (MDD) considered to be in partial remission?

When to Diagnose MDD in Partial Remission

A patient with Major Depressive Disorder is diagnosed as being in partial remission when they demonstrate 25-50% improvement in depressive symptoms after adequate treatment (minimum approved dosage for at least 4 weeks), but continue to have residual symptoms that prevent full remission. 1

Defining Partial Remission

Partial remission (also called Partially Responsive Depression or PRD) can be diagnosed after even a single adequate treatment trial that produces 25-50% symptom improvement. 1 This distinguishes it from treatment-resistant depression (TRD), which requires less than 25% improvement after two adequate treatment trials. 1

Key Diagnostic Criteria

• Symptom improvement threshold: The patient must show 25-50% reduction in depressive symptom severity from baseline 1
• Adequate treatment exposure: Minimum approved dosage administered for at least 4 weeks 1
• Persistent residual symptoms: Despite improvement, the patient has not achieved full remission (MADRS >10 or HAM-D17 >7) 1
• Current episode focus: The partial response should be documented within the current depressive episode 1

Assessment Tools for Partial Remission

The Montgomery-Åsberg Depression Rating Scale (MADRS-10) is the preferred clinician-administered instrument, combined with the patient-reported Quick Inventory of Depressive Symptomatology Self-Report (QIDS-SR). 1

Measurement Standards

• Full remission cutoffs: MADRS ≤10 or HAM-D17 ≤7 1
• Response definition: ≥50% reduction in symptom severity 1
• Partial response definition: 25-50% reduction in symptom severity 1
• Do not use shortened scales: Full scales (MADRS-10, HAM-D17) should be used rather than abbreviated versions (MADRS-6, HAM-D6) for accurate assessment 1

Clinical Significance of Partial Remission

Residual symptoms in partial remission are powerful predictors of relapse, with relapse rates 3-6 times higher than in patients achieving full remission. 2 Approximately one-third of patients achieve only partial remission rather than full remission, making this a clinically common and important state. 2

Associated Morbidity

• Functional impairment: Patients with residual symptoms experience continued disability despite improvement 2, 3
• Increased healthcare utilization: More medical and psychiatric visits, increased public assistance needs 2
• Suicide risk: Higher rates of suicidal thoughts and attempts 2
• Chronicity risk: Partial remission is associated with progression to chronic depression 2
• Medical complications: Increased risk of stroke and coronary events 2

Documentation Requirements

Proper documentation must include dose administered, duration of treatment, objective measurement of symptom severity using validated scales, and assessment of medication adherence. 1, 4

Essential Documentation Elements

• Treatment history: Document the specific antidepressant(s) used, including generic and brand names 1
• Dosing verification: Confirm the dose met or exceeded minimum approved dosage 1, 4
• Duration confirmation: Verify at least 4 weeks of treatment at adequate dose 1, 4
• Baseline and follow-up scores: Use MADRS or HAM-D at baseline and after treatment to calculate percentage improvement 1, 4
• Adherence assessment: Document medication adherence through clinical documentation, pharmacy records, or plasma level monitoring when available 1

Common Pitfalls to Avoid

Do not diagnose partial remission if treatment was discontinued before 4 weeks without clear evidence of lack of response. 4 This represents an inadequate trial rather than partial remission.

Critical Considerations

• Exclude bipolar disorder: Screen for previous manic, hypomanic, or subthreshold bipolar symptoms, as these patients require different treatment approaches 1, 4
• Assess comorbidities: Personality disorders or substance use disorders with onset antecedent to MDD may confound the diagnosis 1
• Verify adherence: Many apparent cases of partial remission may represent non-adherence rather than true partial response 1
• Consider substance use: Severe substance use disorder not in remission should be addressed before confirming MDD partial remission 1

Treatment Implications

After documenting partial remission, consider dose optimization before switching medications, as this may achieve full remission. 4 If partial remission persists despite optimization, the patient may benefit from augmentation strategies, combination therapy, or psychotherapy. 5

Evidence for Psychotherapy

Psychotherapy targeting partial remission is associated with superior remission rates at post-treatment (OR 2.57) and at 6-month follow-up (OR 1.75), meaning patients are approximately twice as likely to achieve full remission. 5 However, long-term prophylactic effects remain unclear. 5