The table compares the main depressive and bipolar categories according to the diagnostic framework of the DSM 5 TR, while incorporating relevant conceptual differences in ICD 11. This is an orienting summary: diagnosis always requires longitudinal reconstruction of episodes, assessment of functional impairment and exclusion of substances, medications, medical conditions and other mental disorders that might better explain the presentation.
The reported duration and symptom thresholds should not be applied in isolation. In particular, the distinction between unipolar depression and bipolar disorder depends on the current or past presence of mania or hypomania; clinical severity cannot be inferred from the category name alone, and the DSM 5 TR and ICD 11 classifications are not perfectly congruent.
| Disorder | Diagnostic core | Duration and course | Characteristic manifestations | Distinguishing feature |
| Major depressive disorder | In the DSM 5 TR, it requires one or more major depressive episodes and no history of a manic or hypomanic episode. A major depressive episode comprises at least five symptoms during the same period, at least one of which is depressed mood or marked loss of interest or pleasure. | Episode symptoms last at least 2 weeks; the disorder may involve a single episode or recurrent episodes. | Depressed mood, anhedonia, changes in sleep and appetite or weight, psychomotor changes, fatigue, guilt or low self worth, cognitive difficulties, and thoughts of death or suicide. | A depressive episode alone does not establish unipolar depression: previous mania and hypomania and other causes of the syndrome must be excluded. |
| Persistent depressive disorder and dysthymia | In the DSM 5 TR, persistent depressive disorder encompasses chronic depression with depressed mood for most of the day, on most days, associated with at least two additional symptoms; a syndrome meeting criteria for a major depressive episode may also be continuously present. ICD 11 instead retains dysthymic disorder as a distinct category. | DSM 5 TR: at least 2 years in adults and at least 1 year in children and adolescents, with no symptom free intervals longer than 2 months during the required period. | Depressed mood, or irritable mood in children and adolescents, appetite and sleep changes, low energy, low self esteem, difficulty concentrating or indecisiveness, and feelings of hopelessness. | The older concept of “dysthymia” and the DSM 5 TR category of persistent depressive disorder are not exact synonyms; comparison with ICD 11 requires caution. |
| Bipolar disorders | Diagnostic family comprising disorders defined by the presence of mania, hypomania or chronic patterns of hypomanic and depressive symptoms, according to the specific category. | Course is generally episodic or recurrent; cyclothymia predominantly has a chronic subthreshold course. | Pathological changes in mood, energy, activity, sleep, thinking and behavior, with depressive manifestations varying across subtypes and phases. | “Bipolar disorder” does not correspond to a single set of criteria: diagnosis must identify the category and reconstruct episodes longitudinally. |
| Bipolar I disorder | At least one manic episode is required. A major depressive episode is common during the course but is not required for a diagnosis of bipolar I disorder. | Mania lasts at least 1 week, or any duration if hospitalization is necessary; the duration requirement does not prevail when severity meets the conditions specified by the criteria. | Elevated, expansive or irritable mood associated with persistently increased energy or activity, with grandiosity, decreased need for sleep, increased speech, accelerated thinking, distractibility, increased goal directed activity and potentially harmful behaviors. | The severity and impairment of mania distinguish bipolar I from bipolar II disorder. Psychosis during an episode of mood elevation makes the episode manic rather than hypomanic. |
| Bipolar II disorder | Requires at least one hypomanic episode and at least one major depressive episode, with no history of a manic episode. | Hypomania lasts at least 4 consecutive days in the DSM 5 TR; major depressive episodes last at least 2 weeks. | Hypomania involves an unequivocal change in functioning observable by others, but not the marked impairment or need for hospitalization characteristic of mania; morbidity may be dominated by depressive episodes. | It is not simply a “milder” form of bipolar I disorder: it can cause severe disability, recurrent depression and suicide risk. |
| Cyclothymic disorder | Numerous periods with hypomanic symptoms that do not meet criteria for a hypomanic episode and numerous periods with depressive symptoms that do not meet criteria for a major depressive episode. | DSM 5 TR: at least 2 years in adults or 1 year in children and adolescents; during this period symptoms are present for at least half the time and symptom free intervals do not exceed 2 months. | Persistent fluctuations in energy, activity, sleep, self esteem and mood without reaching the episodic thresholds for mania, hypomania or major depression during the required period. | It is a bipolar spectrum disorder distinct from normal mood variations and from full episodic bipolar presentations. |
| Other specified or unspecified bipolar and related disorder | Symptoms characteristic of the bipolar spectrum cause clinically significant distress or impairment but do not fully meet the requirements of a more specific bipolar disorder. | Variable depending on the presentation. Examples in the DSM 5 TR updated in 2025 include short duration hypomanic like episodes and cyclothymic like disorder of insufficient duration. | Subthreshold manic or hypomanic manifestations, episodes that are too brief or cyclothymic patterns of insufficient duration, according to the specific presentation. | Other specified explicitly states why the requirements of a more defined disorder are not met; unspecified does not state that reason, often because the available information is insufficient. |
| Other specified or unspecified depressive disorder | Clinically significant depressive symptoms predominate but do not meet the full requirements of a more specific depressive disorder. | Variable. DSM 5 TR examples include recurrent brief depression, short duration depressive like episodes lasting 4 to 13 days and depressive like episode with insufficient symptoms lasting at least 2 weeks. | Depressed mood and other depressive symptoms whose duration, number or configuration do not reach a more specific category, but with clinically significant distress or impairment. | As with residual bipolar categories, the other specified form states the diagnostic reason; the unspecified form is used when that reason is not specified. |
The September 2025 DSM 5 TR update changed the nomenclature of some presentations within the categories Other Specified Bipolar and Related Disorder and Other Specified Depressive Disorder, introducing wording with like to clarify that the presentation resembles a defined syndrome but lacks a specific requirement. For this reason, the updated official English terms are used in the table where an Italian translation could obscure this technical distinction.
ICD 11 organizes some of these conditions differently from DSM 5 TR, so a DSM category should not automatically be converted into an apparently equivalent ICD category. The dedicated pages describe the relevant differences and the complete clinical framework.
Informational notice: the information contained on this page is provided solely for informational and educational purposes and does not replace the advice, diagnosis or treatment provided by a physician. If needed, always consult a qualified healthcare professional.
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