Differential diagnoses and comorbidities
Unipolar depression is a common initial misdiagnosis for bipolar disorder. And while mania is a core component of bipolar, it can occur in other conditions such as seasonal affective disorder, postpartum psychosis, and schizo-affective disorder.6,7
Mood changes can also result from dementia, multiple sclerosis, lupus, brain injuries, stroke, brain tumour, encephalitis, or drug or alcohol misuse among many others, but some conditions can be comorbidities.
Metabolic disorders that can confuse a bipolar diagnosis include hyperthyroidism, Cushing's disease, Addison's disease, vitamin B12 deficiency, and renal dialysis.7
The most common comorbidities in people with bipolar disorder include anxiety disorders, alcohol and substance misuse, and personality disorders. Comorbidity occurs in two-thirds of people with bipolar disorder throughout their lifetimes.7
Medications that may result in a misdiagnosis of bipolar include use of antidepressants, corticosteroids, levodopa, pramipexole, and prescribed stimulants (such as methylphenidate).7
NICE warns that child abuse may be a contributory factor to or a cause of bipolar disorder in children.7