Even though there aren't any specific tests used to diagnose BPD, others can be used to eliminate presence of other conditions. These can include:

• Serum pregnancy test in women;
• Urine toxicology tests to determine if the person is using drugs or medication;
• CT and MRI scans of the brain;
• ECG, electrolytes, glucose level, liver function tests, thyroid function tests, and urinalysis.

A diagnosis can only be established if symptoms have ended after one month. However, within that month, a clinician might diagnose the patient with a general psychotic disorder before giving a final diagnosis, as symptoms may change.