In the DSM-IV, a mixed episode was an independent category. In the DSM-5-TR it was replaced by the with mixed features specifier, applicable to manic, hypomanic or depressive episodes when significant symptoms of the opposite pole are present. The ICD-11 instead retains a mixed episode category; terminology must therefore be referenced to the classification system used.
In the DSM-5-TR, the with mixed features specifier requires at least three significant depressive symptoms during a manic or hypomanic episode, or at least three manic or hypomanic symptoms during a major depressive episode. The symptoms must be observable and represent a change from usual behavior; substances and other medical conditions must also be excluded.
In the DSM-5-TR, mixed features indicate the concomitant presence, during a depressive, manic or hypomanic episode, of at least three qualifying symptoms of the opposite pole. Rapid mood shifts or irritability alone are insufficient. Psychomotor agitation and suicidal ideation, or increased energy and depressive symptoms, may coexist, for example.
Mixed features may occur at different ages and phases of the disorder. There is no validated bimodal distribution that identifies young people and adults over 60 years as typical groups.
The coexistence of manic and depressive symptoms makes a mixed episode particularly challenging to recognize. Patients may simultaneously present with:
The coexistence of depressive and activation symptoms may be associated with impulsivity and a high risk of self-harm or suicidal behavior. The urgency of management depends on suicidal ideation or plan, agitation, psychosis, functional impairment and capacity for self-protection, and requires prompt assessment when these elements are present.
In the DSM-5-TR, mixed features do not constitute an independent episode: they are specified within the current manic, hypomanic or depressive episode. Severity, psychotic features, catatonia, remission and peripartum onset are described with the specifiers applicable to the underlying episode.
Diagnostic classification and treatment must be entrusted to a specialist, with dynamic assessment of suicide risk, agitation, substances and comorbidities. Treatment depends on the underlying episode and severity; antipsychotics or mood stabilizers may be indicated, whereas antidepressants require particular caution in the presence of mixed features.