A bipolar I disorder diagnosis is easy to make or rule out early—if you understand the diagnostic criteria. If you’re a PMHNP or other mental health provider, always start by ruling out mania. To accurately diagnose bipolar disorder, look for a history of mood elevation or persistent irritability lasting at least one week, with symptoms present 50% of the day, every day.
Use the DIGFAST mnemonic:
Distractibility
Impulsivity
Grandiosity
Flight of ideas
Activity increase
Sleep deficit
Talkativeness
Pro tip: Most providers only assess for euphoric mood—but some patients may only present with irritability. Missing this is a common diagnostic error.
Bipolar I Disorder: Features to Watch For
To diagnose bipolar I disorder, look for:
- At least a week of manic symptoms (may include psychosis)
- Manic highs severe enough to cause hospitalization
- Similar prevalence in males and females
- Lows to highs ratio of approximately 3:1
Bipolar II Disorder: More Depression, Less Mania
Key differences for bipolar II:
- Hypomania lasts at least 4 but less than 7 days
- Must have hypomania plus at least one Major Depressive Episode
- Higher prevalence in females
- Lows to highs ratio is about 39:1
Don’t Miss the Diagnosis
If you’re not screening for mania in every patient presenting with mood symptoms, you’re missing a critical step. Depression is extremely common—and sometimes misleading.
In fact, up to 60% of patients with bipolar depression are misdiagnosed with unipolar depression, and it can take up to 10 years for the correct diagnosis to be made.
As a psych NP, knowing how to diagnose bipolar disorder correctly is crucial. Recognizing those few days of hypomania in bipolar II could change a patient’s entire trajectory of care.
Read more from the National Institute of Mental Health on bipolar disorder
Continue Learning
Want better clarity on confusing diagnoses like how to distinguish Major Depressive Disorder from bipolar II disorder?
Read this related blog post.
And, if you’re ready to diagnose and treat your patients with more confidence, check out the Mental Disorders Crash Course.