F34

F34 is a code category in the ICD-10 classification system used by clinicians and researchers to identify persistent mood disorders. It sits within the broader range of mood disorders (codes F30–F39) and specifically designates conditions in which mood disturbance is chronic and does not meet the full criteria for a major depressive episode or a manic episode.

Subcategories commonly associated with F34 include F34.0 Cyclothymia and F34.1 Dysthymic disorder, with additional codes such as F34.8 Other persistent mood disorders and F34.9 Persistent mood disorder, unspecified. Cyclothymia refers to a long-lasting pattern of mood fluctuations involving periods of hypomanic symptoms and depressive symptoms that do not reach the thresholds for bipolar disorder. Dysthymic disorder, also known as persistent depressive disorder in some diagnostic systems, involves a chronically low mood with a constellation of depressive symptoms that are less severe than those seen in major depressive episodes.

Diagnosis is based on clinical evaluation, patient history, and symptom patterns over time, often after ruling out other medical or substance-related causes. Comorbidity with anxiety disorders and substance use disorders is common, and differential diagnosis may include major depressive disorder and bipolar spectrum disorders.

Treatment typically combines psychotherapy and pharmacotherapy. Psychotherapeutic approaches may include cognitive-behavioral therapy and interpersonal therapy. Medication choices vary by subtype and patient history; mood stabilizers or atypical antipsychotics may be used in certain cases, particularly when cyclothymic or dysthymic symptoms are persistent or recurrent. Management focuses on reducing symptom burden, improving functioning, and supporting long-term stability.