Clinical Psychiatry

Secondary mood syndrome

ICD-10F06.3Organic mood [affective] disorders
DSM-5-TRF06.3xDepressive Disorder Due to Another Medical Condition

1. Definition and nosology

Secondary mood syndrome (ICD-11: 6E62; DSM-5-TR: F06.3x Mood Disorder Due to Another Medical Condition) — depressive, manic, or mixed mood episodes as a direct physiological consequence of another medical condition.

2. History

The term “Organic Affective Disorder” belongs to the 20th century; current clinical practice has moved toward the biopsychosocial model.

3. Epidemiology

  1. Depressive symptoms are prevalent in chronic medical conditions; some meet criteria for clinical depressive episode.
  2. Steroid-induced mood disorders — high-dose prednisone 5–18% mania/hypomania, depression.
  3. Interferon-induced depression — 20–40% in HCV treatment.
  4. Post-stroke depression — 30%.

4. Etiology and pathogenesis

  • Endocrine — hypothyroid (depression), hyperthyroid (mania-like), Cushing, Addison.
  • Neurological — stroke (left frontal — depression, right — mania), Parkinson’s, MS, brain tumor, dementia, TBI.
  • Substance/medication — steroids, interferon, dopamine agonists, isotretinoin, β-blocker, anticonvulsant.
  • Metabolic — uremia, B12, folate.
  • Infectious — HIV, syphilis, COVID.
  • Autoimmune — lupus, Hashimoto.
  • Oncology — pancreatic cancer (classic depressive presentation), paraneoplastic.

5. Clinical features

  • Symptoms of depressive, manic, mixed, and hypomanic episodes.
  • Medical condition or substance-related temporal association.
  • Features not characteristic of classic affective disorder (late onset, atypical presentation).

6. Diagnosis

6.1 Unified diagnostic criteria

A. Persistent mood disturbance (depressive, manic, or mixed).

B. Evidence of a medical condition (non-psychiatric).

C. Not better explained by a primary affective disorder.

D. Does not occur in the context of delirium.

6.2 Differences between sources

  • ICD-11 — a substance-induced mood disorder does NOT belong here: it lives in the substance chapter. 6E62 covers only health conditions outside the mental-disorders chapter and is assigned alongside the diagnosis of the underlying disease.
  • Consultation-liaison protocols.

6.3 Diagnostic algorithm

  • Clinical interview + medical history.
  • Medical and laboratory assessment (TSH, B12, cortisol, renal, hepatic).
  • Medication list review.
  • Brain imaging (stroke, MS, tumor).
  • Toxicology.
  • Comorbid disorders.

6.4 Differential diagnosis

Condition Distinguishing feature
MDD first (6A70/6A71) There is no medical cause.
Bipolar first History of affective episodes without a medical cause.
Adjustment disorder (6B43) Response to stress factor.
Delirium (6D70) Fluctuation of attention.

7. Examination and assessment

  1. PHQ-9, MADRS, YMRS.
  2. Laboratory: TSH, B12, cortisol, ANA, kidney, liver.
  3. MRI in atypical cases.
  4. C-SSRS.

8. Treatment

  • Etiological treatment — correction of medical condition or medication.
  • Symptomatic psychiatric treatment:
    1. Depressive — SSRIs (disease-specific selection; cardiac — sertraline, escitalopram; oncology — mirtazapine);
    2. Manic — antipsychotic (quetiapine, olanzapine); in steroid-induced mania, taper steroids or use antipsychotic;
    3. Mixed or refractory — ECT. Multidisciplinary approach — psychiatrist, the specialist treating the underlying illness, and social support.

8.1 Treatment methods

  • SSRI Illness-Specific — Choice appropriate to cardiac, oncological, neurological context.
  • ECT — In refractory and severe cases.

9. Prognosis

Most remissions with etiological intervention.

10. Myths and misconceptions

Myth 1: “Depression is ‘normal’ for a patient with a medical illness”

Evidence: Clinical depression worsens the course of the medical condition; requires active intervention.

Myth 2: “Steroid-induced mania resolves on its own”

Evidence: dose reduction or antipsychotic addition required.

Myth 3: “Antidepressant is first-line in hypothyroidism”

Evidence: thyroid correction first; antidepressants for residual symptoms.

Myth 4: “Interferon depression is rare”

Evidence: HCV interferon therapy 20–40% — active monitoring required.

11. Sources

  1. WHO. ICD-11. 6E62 Secondary mood syndrome. 2024.
  2. APA. DSM-5-TR. 2022.
  3. Levenson J.L. (ed.). APA Publishing Textbook of Psychosomatic Medicine and Consultation-Liaison Psychiatry. 3rd ed. 2018.
  4. Robinson R.G., Jorge R.E. Post-stroke depression: a review. Am J Psychiatry 2016;173(3):221–231. doi:10.1176/appi.ajp.2015.15030363