What are the DSM‑5 criteria for mood disorders, including major depressive episode, persistent depressive disorder, bipolar I disorder, bipolar II disorder, and cyclothymic disorder?

DSM Criteria for Mood Disorders

The DSM-5 separates mood disorders into two distinct chapters: "Depressive Disorders" and "Bipolar and Related Disorders," replacing the unified "Mood Disorders" chapter from DSM-IV. This structural change reflects a fundamental reconceptualization of these conditions as separate diagnostic entities rather than variations of a single disorder spectrum 1, 2, 3.

Major Depressive Disorder (MDD)

For MDD diagnosis, you must identify 5 or more specific symptoms present during the same 2-week period, representing a change from previous functioning, with at least one symptom being either depressed mood or loss of interest/pleasure 1, 4.

Core Diagnostic Criteria:

The 9 symptoms to assess are:

1. Depressed mood most of the day, nearly every day (in children/adolescents, can present as irritable mood)
2. Markedly diminished interest or pleasure in all or nearly all activities most of the day, nearly every day
3. Significant weight loss/gain (>5% body weight in a month) or appetite changes (in children, include failure to make expected weight gains)
4. Insomnia or hypersomnia nearly every day
5. Psychomotor agitation or retardation nearly every day (observable by others, not just subjective feelings)
6. Fatigue or loss of energy nearly every day
7. Feelings of worthlessness or inappropriate guilt (may be delusional) nearly every day
8. Diminished ability to think, concentrate, or indecisiveness nearly every day
9. Recurrent thoughts of death, suicidal ideation, suicide attempt, or specific plan 1, 4

Additional Required Criteria:

• Symptoms cause clinically significant distress or impairment in social, occupational, or other important functioning
• Symptoms are not due to direct physiologic effects of substances (drugs, medications) or general medical conditions (e.g., hypothyroidism)
• Symptoms do not meet criteria for a mixed episode (simultaneous manic and depressive symptoms)
• Not better accounted for by bereavement (though DSM-5 removed the bereavement exclusion, replacing it with clinical judgment to distinguish normal grief from pathological depression) 1, 5

Severity Classification:

Mild depression: 5-6 symptoms of mild severity with minimal functional impairment

Moderate depression: Symptom count and severity between mild and severe

Severe depression: All 9 symptoms present, OR presence of specific suicide plan/intent/recent attempt, psychotic symptoms, first-degree family history of bipolar disorder, or severe functional impairment (unable to leave home) 6

Persistent Depressive Disorder (Dysthymia)

DSM-5 created this new category to encompass both chronic depression and dysthymia from DSM-IV 5, 7. This diagnosis requires depressed mood on most days for at least 2 years in adults (1 year in children/adolescents) 4. The relationship between this diagnosis and concurrent MDD remains ambiguous in DSM-5, with conflicting guidance on whether both diagnoses should be assigned simultaneously when criteria for both are met 5.

Bipolar I Disorder

Bipolar I requires occurrence of at least one manic or mixed episode lasting at least 7 days (or any duration if hospitalization is required) 2. Depressive episodes are not required for diagnosis, though most patients experience them during their lifetime.

Manic Episode Criteria:

DSM-5 added a critical entry criterion: both abnormally elevated/irritable mood AND increased energy/activity must be present 8, 9. This represents a significant change that may reclassify some DSM-IV bipolar I patients to subdiagnostic categories.

The episode must include:

• Distinct period of abnormally and persistently elevated, expansive, or irritable mood
• Abnormally and persistently increased goal-directed activity or energy
• Duration of at least 7 days (or any duration if hospitalization needed)
• Represents significant departure from baseline functioning 2

Mixed Episode:

A period lasting 7 days or more where criteria for both manic and depressive episodes are simultaneously met 2. Note that DSM-5 eliminated the mixed episode as a separate entity, replacing it with a "mixed features" specifier 9.

Bipolar II Disorder

Bipolar II requires at least one hypomanic episode (lasting at least 4 days) and at least one major depressive episode, but no full manic or mixed episodes 2, 10, 2. This diagnosis was added to ICD-11 to harmonize with DSM-5 9.

Key Distinguishing Features from Bipolar I:

Bipolar II patients typically present with:

• Later "bipolar" presentation and older age at first hypomania
• More frequent depressive onset and early depressive episodes
• Depressive predominant polarity
• More chronic fluctuating course rather than episodic
• Higher rates of rapid cycling
• More antidepressant use and less mood stabilizer use during early course 11

Cyclothymic Disorder

While not extensively detailed in the provided evidence, cyclothymic disorder involves numerous periods of hypomanic symptoms and depressive symptoms that do not meet full criteria for hypomanic or depressive episodes, persisting for at least 2 years in adults.

Important Clinical Considerations:

Rapid cycling is defined as at least 4 mood episodes in 1 year, with episodes still meeting full duration criteria (e.g., 7 days for mania) 2. This differs from some pediatric literature definitions.

The bereavement exclusion was removed in DSM-5, replaced with clinical judgment to distinguish normal grief reactions from pathological depression requiring treatment 5, 9. This makes diagnosis less objective and more dependent on clinician assessment.

New DSM-5 specifiers include "with anxious distress," "with mixed features," and "with perinatal onset" (expanded from postnatal to include pregnancy onset) 5, 7.