Often people with bipolar disorder also have anxiety symptoms or anxiety disorders. Anxiety may be symptomatic of the depressed phase of manic-depressive disorder but it can also indicate a separate anxiety disorder. In fact anxiety without any underlying medical illness, i.e. as a psychiatric symptom commonly co-occurs with bipolar.

Anxiety is more prevalent with bipolar disorder than with unipolar depression and the incidence amongst the bipolar spectrum disorders is higher than those in the general population.