This 15-min test tells if you've been misdiagnosed with depression

A simple 15-minute electrocardiogram could help a physician determine whether a patient has major depression or bipolar disorder, suggests a study.

Bipolar disorder often is misdiagnosed as major depression. But while the symptoms of the depressive phase of bipolar disorder are similar to that of major depression, the treatments are different and often challenging for the physician.

In bipolar disorder, formerly called manic depression, a patient swings between an emotional high (manic episode) and severe depression. Treatment for the depressed phase includes an antidepressant along with a safeguard such as a mood stabilizer or antipsychotic drug to prevent a switch to a manic episode. A physician who misdiagnoses bipolar disorder as major depression could inadvertently trigger a manic episode by prescribing an antidepressant without a safeguard mood stabilizing drug.

The Loyola Medicine study found that heart rate variability, as measured by an electrocardiogram, indicated whether subjects had major depression or bipolar disorder.

Senior author Angelos Halaris noted that having a noninvasive, easy-to-use and affordable test to differentiate between major depression and bipolar disorder would be a major breakthrough in both psychiatric and primary care practices.

He added that further research is needed to confirm the study's findings and determine their clinical significance.

The Loyola study enrolled 64 adults with major depression and 37 adults with bipolar disorder. All subjects underwent electrocardiograms at the start of the study. Each participant rested comfortably on an exam table while a three-lead electrocardiogram was attached to the chest. After the patient rested for 15 minutes, the electrocardiographic data were collected for 15 minutes.

The study appears in World Journal of Biological Psychiatry.