The Difference Between Bipolar and Unipolar Depression

Bipolar Depressions: An Update

Bipolar Depressive Episodes and Unipolar Depressive Episodes or what are often simply called Depressive Episodes, according to the DSM 5, are indistinguishable from each other in their symptoms.  However, It is essential to note that the treatment for Bipolar Depression is most often (if it is to be effective) rather different from the treatment of Unipolar Depressive episodes.

These treatment differences are essential to understand, because they may very well mean the difference between improvement and failure to improve, or, even worsening symptoms.

More information about Bipolar Disorder in general and the available treatments for all phases of illnesses can be found here and here

Research into the most effective treatment for Bipolar Depression remains an active field in psychiatry, so new treatment options are becoming available frequently. This author will point out when a treatment is thought promising by leading physicians in the field, but has yet to be approved by the FDA. One caveat to remember is that all of your treatment should be reviewed with your psychiatrist. No changes to your treatment plan or medications or doses should be made without first discussing any changes you are interested in or have questions about with your treating doc! There is no substitute for the direct care of a physician.

Bipolar I disorder (BP I) affects approximately 1% of adults. Unfortunately, it is very common for an initial depressive episode in a patient suffering from BP I to be misdiagnosed (most commonly as Unipolar Depression, followed by an Anxiety Disorder). In one study, patients saw an average of 4 physicians before receiving the proper diagnosis.


Why are so many patients receiving the wrong diagnosis? Why is that important? And what can we do?


The definition of a Major Depressive Episode in both BP I and Major Depression are exactly the same. This can lead to some diagnostic confusion. When a patient presents for care with depressive symptoms only, to make the proper diagnosis, it is very important for the doctor and patient to review the following:

  1. Is there any past history of mania (symptoms may include: a period of time when the patient felt they had little need for sleep, felt high or irritable, and simultaneously experienced behavior changes that may have included having racing thoughts, feeling restless or distracted, speaking quickly or in a pressured manner, having had an unrealistic perception of one’s own abilities, or having engaged in impulsive and/or high risk behaviors, or taking on many new projects at once)? A positive history of mania, hypomania, or mixed episodes dictates that the patient is suffering from bipolar depression and will likely only improve if the proper treatment for bipolar depression is given.
  1. A history of multiple mood cycles, or highly recurrent mood episodes is more consistent with bipolar disorder than with MDD.
  2. Earlier onset of illness as well as abrupt onset of mood episodes with similarly abrupt end points may be a tip off to bipolar depression.
  3. Another very important factor is Family History. A patient with a first degree relative with a history of Bipolar D/O should be evaluated carefully for the disorder.
  4. Patients presenting with significant anxiety or agitation or predominantly atypical depressive symptoms (Hypersomnolence, Psychomotor retardation, and melancholic features which are more common in bipolar disorder) may also prompt suspicion.
  5. Finally, any patient with psychosis should be evaluated for Bipolar D/O, as well as any patient with history of hypomania or mixed episodes, any patients who have experienced mania or hypomania in response to anti-depressant treatment or who have failed to respond to two anti-depressants should be evaluated for diagnosis of Bipolar Disorder.


Treatment Options for Bipolar Depression

If it has been determined that your Depressive Episode is due to Bipolar Disorder, it is important to know the pharmacologic (medicine) treatments for this type of depression are the ones that should be used. So what are they?

Currently, there are only three FDA approved treatment approached for acute Bipolar Depression. These are:

  1.  Lurasidone (Latuda), as monotherapy or adjunctive therapy
  2. Quetiapine monotherapy
  3. Olanzapine and fluoxetine combined

Despite lack of FDA approval, many authors consider Lithium, lamotrigine, and divalproex, alone (lithium and lamotrigine) or in combination with each other, olanzapine, or SSRI other potential good options, though again, they do not yet carry FDA approval for acute treatment of bipolar depression. 

It is essential to note that in the large STEP-BD study, anti-depressants alone were found to be no more effective than placebo in treating bipolar depression.

Be sure to review your mood symptoms and medications with your Psychiatrist! If you have any questions about Bipolar Depression or Bipolar Disorder feel free to email me at  and Be Well!


Hirschfeld RM, Lewis L, Vornik LA Perceptions and the impact of bipolar disorder: how far have we really come? Results of the national depressive and manic-depressive association 2000 survey of individuals with bipolar disorder. J Clin Psychiatry. 2003;64:161-174. 

Motovsky B, Pecenak J, Psychopathological characteristics of bipolar and unipolar depression - potential indicators of bipolarity. Psychiatr Danub. 2013 Mar;25(1):34-9. 

Reinares M, Rosa AR, Franco C, et al. A systematic review on the role of anticonvulants in the treatment of acute bipolar depression. Int J Neuropsychopharmacol. 2013;15:485-496. Abstract

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