Bipolar Disorder Versus Borderline Personality Disorder

Depressive signs of bipolar disorder and borderline personality disorder found to be different

(RxWiki News) Depression can be a symptom of both bipolar disorder and borderline personality disorder. Because of a patient's depressive symptoms, these two conditions may often be misdiagnosed or confused.

A recent study looked at the differences between bipolar disorder and borderline personality disorder in order to distinguish between the two diagnoses for treatment purposes.

The researchers found that the participants with borderline personality disorder were more likely to have additional disorders and more likely to have experienced childhood trauma than participants with bipolar disorder. Those with borderline personality disorder also reported longer and more severe depressive episodes.

The researchers concluded that patients with these two conditions differed significantly in their clinical and familial histories, thus supporting that the two conditions are different and should be treated as such.

"Talk to a psychiatrist if you are feeling depressed."

The lead author of this study was Mark Zimmerman, MD, from the Department of Psychiatry at Rhode Island Hospital and the Department of Psychiatry and Human Behavior at Brown Medical School in Providence, Rhode Island.

The researchers interviewed 268 participants between December 1995 and May 2012. There were 62 participants diagnosed with bipolar II depression and 206 participants diagnosed with major depressive disorder with comorbid (co-occurring) borderline personality disorder (MDD-BPD). Depressive episodes are a part of bipolar disorder. Depression is a separate disorder that can co-occur with borderline personality disorder.

Bipolar disorder is a condition that causes sudden changes in mood, energy and activity levels that can affect day-to-day activities. Borderline personality disorder is a condition that causes problems with regulating emotions and thoughts, impulsive and reckless behavior and unstable relationships with others.

All the participants were between the ages of 18 and 68, and could not be diagnosed with both bipolar disorder and borderline personality disorder. They also had to meet the official criteria for experiencing a major depressive episode at the time of the interviews. These criteria include five or more of the following:

  • Unusually depressed mood
  • Loss of interest of previously enjoyable things or activities
  • Changes in eating, appetite or weight
  • Excessive sleep
  • Unusually unsettled or sluggish behavior
  • Extreme feelings of guilt or worthlessness
  • Trouble with concentration
  • Suicidal thinking

The researchers found that the average age of the patients in the MDD-BPD group was 33 years old, compared to 37 years old in the bipolar group. The MDD-BPD patients were also less likely to be married. The average age at disorder development was below 20 years old and did not differ between the groups.

The findings showed that, between the two groups, there were no significant differences in race, education level, gender, the average number of psychiatric hospitalizations or amount of time spent away from work due to psychiatric reasons in the five years before the study.

The researchers found that 38 percent of the MDD-BPD group were also diagnosed with three or more non-personality disorders (i.e., anxiety, mood and eating disorders) compared to 26 percent of the bipolar group. The average number of non-personality disorders in the MDD-BPD group was 2.7 versus 1.8 in the bipolar group.

Most of the participants in both groups were diagnosed with an anxiety disorder, but the rate was much higher in the MDD-BPD group. Thirty percent of the MDD-BPD group was diagnosed with post-traumatic stress disorder, or PTSD (a severe condition that may develop after a person is exposed to one or more traumatic events), compared to 10 percent of the bipolar group. PTSD was the one specific anxiety disorder that had a significantly higher rate within the MDD-BPD group.

Those in the MDD-BPD group had longer depressive episodes, were overall more depressed, had a harder time doing day-to-day activities, and had significantly more childhood trauma events — especially physical neglect — than the bipolar group. The researchers also found that the MDD-BPD group was more suicidal, with twice as many MDD-BPD participants as bipolar participants reporting three or more suicide attempts.

Overall, the researchers found that the only thing that was more common in the bipolar participants was having an immediate family member with a history of bipolar disorder. 

The researchers suggest that there are specific signs that doctors should consider before deciding which disorder to diagnose: the way a patient expresses unstable emotions, a patient's specific history of childhood trauma, whether or not a patient is also diagnosed with PTSD, and if there is a family history of bipolar disorder.

The authors noted a couple limitations of their study. First, this study was based out of a single outpatient practice where most of the patients were white, female and had health insurance. Second, the researchers only focused on patients who were depressed at the time of initial evaluation; this could have biased the researchers' assessment of some personality disorders.

This study was published in the September edition of The Journal of Clinical Psychiatry.

Review Date: 
October 9, 2013