14th February 2025

Presentation and diagnosis of bipolar disorder

Bipolar disorder requires two mood episodes, at least one of which is manic, hypomanic or mixed (see below), with full recovery between them.

Mania

A manic episode is an elevated mood state lasting at least one week (unless treated). It presents with elation, irritability or expansive mood, with features such as increased energy, increased self-esteem and grandiose ideas, reduced sleep, and impulsivity. There may be pressured or rapid speech and flight of ideas.

As with any mental disorder, there is disruption of occupational, social and/or interpersonal functioning. This may lead to poor self-care, such as poor oral intake and maintenance of living conditions.

When more severe, mania can present with psychotic symptoms, which are usually consistent with the person’s mood. Grandiose ideas may become delusions, for example involving special powers or abilities. Similarly, paranoid ideas may develop into persecutory delusions.

Psychiatric differential diagnoses include anxiety disorders, ADHD, personality disorder and alcohol or substance misuse. Organic illness can also cause manic features, such as hyperthyroidism, Cushing’s, encephalopathies and epilepsy. These must be considered and investigated with blood tests, brain imaging and EEG as appropriate.

Hypomania

This is a milder version of mania, whereby symptoms are less severe and do not cause occupational and social dysfunction. The minimum length of an episode is four days. By definition, hypomania does not lead to hospital admission or involve psychotic features.

Depressive episodes

Depressive episodes in bipolar affective disorder present in a similar fashion to a unipolar depressive disorder. This often leads to misdiagnosis.

Mixed episodes

In mixed bipolar episodes there are both manic and depressive features for at least two weeks. Mixed episodes typically present as depression with overactivity, mania with reduced energy, dysphoria with manic symptoms, and rapid cycling between manic and depressive symptoms.