Bipolar disorder can be difficult to diagnose as:
- its onset is often marked by a depressive period and it can therefore be misdiagnosed as depression
- depressive symptoms are common in bipolar disorder – usually more prevalent than hypomanic or manic symptoms
- ‘mixed mood’ episodes are common. These might obscure detection of mania and hypomania, as people report more depressive symptoms when seeking treatment.
For some people, it can take years before their illness is accurately diagnosed and treated.
Mental health professionals should carefully assess previous episodes of mania or hypomania when working with depressed patients. Some patients with treatment-resistant unipolar depression may possibly have misdiagnosed bipolar disorder.