F31

F31 is the ICD-10-CM diagnostic code for bipolar affective disorder, a psychiatric condition characterized by recurrent mood episodes. The category covers bipolar I and bipolar II disorders, as well as related presentations such as mixed episodes and episodes in remission, with subcodes specifying the current episode type and remission status.

Clinical features of bipolar affective disorder include episodes of mania or hypomania and episodes of depression, with intervening periods of euthymia. Manic or hypomanic episodes involve elevated or irritable mood, increased energy, decreased need for sleep, rapid speech, pressured thoughts, distractibility, and often risky behavior. Depressive episodes feature persistent sadness or emptiness, anhedonia, fatigue, sleep and appetite changes, diminished concentration, and possible thoughts of suicide. Episodes can last days to weeks, and individuals may experience varying degrees of impairment.

Diagnosis and coding rely on clinical assessment, patient history, and structured interviews. In ICD-10-CM, F31 codes specify the current episode type (for example, hypomanic, manic, depressed, or mixed) and states such as remission or unspecified status, enabling standardized documentation across clinical settings.

Treatment and prognosis focus on mood stabilization and prevention of relapse. Common approaches include mood stabilizers (such as lithium or valproate), second-generation antipsychotics, and cautious use of antidepressants when indicated. Psychotherapy, psychoeducation, and adherence support are important components of care. With sustained treatment, many individuals achieve symptom control and functional improvement, though bipolar disorder is typically lifelong and requires ongoing management. Suicide risk is a critical consideration, particularly during depressive or mixed episodes.