Borderline Personality Disorder vs. Bipolar Disorder: How Can You Tell The Two Apart

 Did you know that there are many similarities between borderline personality disorder (BPD) and bipolar disorder (BD)?  There are so many similarities between the two disorders that there has been a controversy among psychiatrists for decades on how to distinguish between the two.  So where does that leave people who are diagnosed with borderline personality disorder and/or bipolar disorder?

I found a review of the available research literature from 2012, Borderline personality disorder and bipolar affective disorder. Spectra or spectre? A review. Dr. Phelps, a psychiatrist who also maintains also provided information and a professional opinion on the differences in diagnosing Bipolar Disorder and Borderline Personality Disorder.

Dr. Phelps  writes that some doctors believe self-harm is the primary difference in diagnosing BPD and Bipolar Disorder. Basically, they believe that because all “borderlines” cut and anybody who cuts are “borderline”.

I hate the term “borderline” as much as “bipolar” because we are not defined by our illness.  Anyways, Dr. Phelps has had many patients with bipolar disorder that self-harm. Working as a mental health nurse on a locked unit, I have seen self-harm occur with many people separate from those who had borderline personality disorder.

Similarities of Bipolar Disorder and Borderline Personality Disorder

Let’s look at all the similarities between the two mental illnesses. 
  • Mood imbalance (non-specific)
  • Atypical depressive features more common than in major depressive disorder – sleeping too much (hypersomnia), increased appetite or weight gain, having a more intense reaction or increased sensitivity to rejection, having a feeling of being weighed down or paralyzed
  • Impulsivity
  • Self-harm is common
  • Early life trauma is significant
  • Psychotic symptoms may occur
  • Highly inherited disorders with possible genetic linkage
  • Similarities in the brain including reduced modulation of limbic activity, increased amygdala activity, reduced size of the hippocampus and the corpus callosum
This table reviews the many differences between bipolar disorder and BPD.
Borderline Personality DisorderBipolar Disorder
Altered sense of selfNo altered sense of self
Chronic emptinessNone
Fear of abandonmentNone
Sex, substances, self-harmSpending, sex, substances, risky
Reactive moodRejection hypersensitivity
Paranoid thoughts come and goParanoid delusions (fixed beliefs)
can occur during a mood episode
Relationships severely disruptedRelationships less severely
No family history of bipolar
Family history of bipolar disorder
Mood imbalances primarily
between depression and anger
Mood imbalances primarily
between depression and euphoria
Higher incidence of suicide
Higher incidence of completed
Very rapid mood cycling – such as abrupt mood changes throughout
the day
Less rapid mood cycling
Psychosis with nonspecific features and sometimes persists over
Psychosis most often linked to the mood state and does not persist over
Early sexual abuse prominentEarly sexual abuse not prominent
There are many brain differences as seen in the table below. 
Borderline Personality DisorderBipolar Disorder
Cognitive deficits* less severeCognitive deficits* more severe
Limited loss of grey and white
More loss of grey and white matter
Alterations in insula activityUncertain changes of insula
No changesReduced activity of dorsolateral/dorsomedial prefrontal cortices
No changesReduced activity of cuneus and lingual gyri
No mitochondrial** dysfunctionMitochondria dysfunction

*Common cognitive deficits are difficulties with word retrieval,difficulties with planning, prioritizing and organizing of behavior (executive functioning), problems with retention of what’s been read or listened to, as well as the experience of mildly dulled or slowed thought processes.

**Mitochondria are the power houses of most cells in the body

Personality Disorder
Bipolar Disorder
Mood stabilizers somewhat
Mood stabilizers very effective
Atypical antipsychotics somewhat
Atypical antipsychotics very
Antidepressants are
not usually effective
Antidepressants are avoided (at
least at first)  
due to the possibility of triggering mania

The basic difference in treatment is that psychotherapy, usually dialectical behavior therapy (DBT), is the first line of treatment for borderline personality disorder and the second line of treatment is medications which are not as effective for people with borderline personality disorder.  Mood stabilizers are more beneficial in BPD than are antidepressants. A 2010 (Cochrane) reviewStoffers concludes:

The available evidence indicates some beneficial effects with second-generation antipsychotics, mood stabilisers, and dietary supplementation by omega-3 fatty acids. However, these are mostly based on single study effect estimates. Antidepressants are not widely supported for BPD treatment…

In bipolar disorder, first-line treatment is medications and second -line treatment is psychotherapy.  While psychotherapy is beneficial to people with bipolar disorder, medication is required for successful recovery in most cases.

As someone with bipolar disorder, I can relate to some degree with people with borderline personality disorder because of similarities in our illnesses such as impulsivity and mood imbalance.  I will never truly know what they go through because I do not have the disorder.

Conclusions we can draw from the research are that although bipolar disorder and borderline personality disorder have a great deal in common, they are still separate illnesses that can also occur together (comorbid).   BPD treatment emphasizes psychotherapy then medications while bipolar disorder treatment emphasizes medications and then psychotherapy.   For more information on atypical bipolar disorder, read more.

How have you been affected by your disorder? Receive the blog posts for the week in  LMW’s weekly newsletter. Leave comments, questions, suggestions, and prayer requests below.

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    This was a really interesting read, thank you for displaying the information in tables, it made it much easier to digest. Thanks for sharing.

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      You’re welcome. I know it was a lot of information. I try to make it easier to read. Maybe it will help people better understand BPD. I hope so.

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