For how long must a patient exhibit an elevated or expansive mood to meet the criteria for mania?

To meet the criteria for mania as defined in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), a patient must exhibit an elevated or expansive mood for at least one week. This duration is essential because it helps differentiate between manic episodes and shorter episodes of mood elevation that may not be severe enough to constitute a disorder.

In addition to the duration, the individual must also experience additional symptoms that cause significant impairment in functioning or necessitate hospitalization to prevent harm to themselves or others. A duration of one week ensures that the mood changes are not just transient and supports the diagnosis of bipolar disorder when considering the broader context of the patient's mood history.

While shorter episodes may occur, they do not fulfill the diagnostic criteria for mania. Hence, the requirement for at least one week of symptoms is key in establishing the diagnosis and appropriate treatment plan.