Aggression Among Adults With Bipolar Disorder

Q&A

We are pleased to present this Q&A with Dr Javier Ballester, MD, lead author of a study published in the journal, Bipolar Disorders, titled "Prospective longitudinal course of aggression among adults with bipolar disorder."¹ Helping to shed light on this often misunderstood topic, Dr Ballester summarizes the most important things for practicing clinicians to know, based on this research.

Q: Can you tell us about the study and what you found? [[{"type":"media","view_mode":"media_crop","fid":"23733","attributes":{"alt":"Javier Ballester, MD","class":"media-image media-image-right","id":"media_crop_3121442176340","media_crop_h":"0","media_crop_image_style":"-1","media_crop_instance":"1951","media_crop_rotate":"0","media_crop_scale_h":"0","media_crop_scale_w":"0","media_crop_w":"0","media_crop_x":"0","media_crop_y":"0","style":"float: right; margin: 10px;","title":" ","typeof":"foaf:Image"}}]]

A: We researched a group of people with bipolar disorder type 1, bipolar disorder type 2, and bipolar NOS.

We compared this group with adults in whom other psychiatric disorders were diagnosed, but with similar psychosocial characteristics, and with the so-called healthy controls-that is, people with no psychiatric diagnosis. We asked all of the subjects to complete the Aggression Questionnaire (AQ) at intake and at years 2 and 4. This is a self-report questionnaire, intended to measure aggressiveness that has been validated in the US and in other countries. The AQ dissects aggression into different subscales, such as verbal, physical and indirect aggression, hostility, and a total measure.

Briefly, we found that:

• subjects with BP scored significantly higher, not only in the total subscale but in every other subscale when compared with the other groups

• subjects scored higher at intake and also at years 2 and 4

• within subjects with BD, those experiencing a current mood episode scored particularly higher when compared with those subjects who were stable, and

• this happened independent of the polarity of the current mood episode-that is, independently if the person with BD was suffering from a manic episode, a mixed episode, or a depressive episode

We think that it is important for clinicians to be able to diagnose and properly treat patients who suffer from BD, especially those who experience an acute mood episode, as this might affect not only these patients but also their families.

Q: We noted a paragraph in your paper, which states:

The finding that subjects with BP reported more aggressiveness may be a potential source of stigma and discrimination . . . However, it is important to emphasize that the . . . results do not mean that subjects with BP are more prone to severe violent behaviors such as homicide, rape, or the use of weapons. In fact, the AQ does not measure severe violent behaviors; it measures hostility, verbal and physical aggression, irritability, and indirect aggression. Moreover, a recent large study . . . showed that patients with BP had more violent behaviors (eg, homicide, assault, robbery, and sexual offenses), but the results were in large part accounted for by the use of substances and not BP per se.¹

This paragraph explains carefully the limited nature of the AQ and distinguishes aggression from violence (eg, homicide, assault, robbery, and sexual offenses) and  include the work by Fazel et al^2,3Do you have concerns that your paper could be misinterpreted, despite that careful paragraph?

A: Definitely [there were concerns], and that is exactly why we added this paragraph. Certainly, these studies are always controversial and touch upon a very sensitive topic. There is a tendency for the public and media to exaggerate, and studies like this can be easily misinterpreted.

We wanted to highlight in our study the difference between aggressiveness and violence. The violent behaviors that we described represent, in our opinion, something qualitatively different. The meta-analysis published by Fazel et al in 2010² showed that the presence of violent behaviors in patients with BD is mainly explained by the concurrent use of drugs. This is why we think it is essential to prevent the use of substances.

Q: Were there clinical experiences that led you to want to look at aggression in BD? Where did the impetus for this line of research come from?

A: I did not personally have any clinical encounters that could lead me to be especially interested in the study of aggression in this population. However, it is known from clinical experience that patients suffering from mania can become easily irritable. I think it was very surprising to find sparse research on this topic, despite the importance of the matter.

Q: You found that the patients-with-bipolar group had a lower socioeconomic status, overall, compared with other patients, though both were well below the healthy controls. Which is chicken and which is egg, do you think? Is there a way to know?

A: This study was not designed to measure the effects of socioeconomic status (SES) in BD. Unfortunately, many individuals with mental disorders have a lower SES than the general population. However, BD might also happen in people with a high SES. In our study we recruited more subjects with low SES, but we also controlled for these differences.

Q: There was a larger drop in AQ scores over time in the bipolar group than in the other 2 groups. Do you think that was a significant finding? What do you think it means? (eg, is this a treatment effect over time?)

A: From the statistical point of view, this was a significant finding, mainly explained by the differences found between time 1 and time 2. Since this is a naturalistic study, meaning that it was not designed to measure the effects of medications or any other treatments over the course of aggression, we cannot find an explanation for this finding. It could be related to the regression to the mean effect frequently found on longitudinal studies but alternative hypothesis are also possible.

Disclosures:

Dr Ballester is currently a second year psychiatry resident at Yale University, New Haven, Connecticut. He completed a psychiatry residency program in Hospital Universitario 12 de Octubre, Madrid, Spain, in 2008 and practiced as an attending psychiatrist in an addiction outpatient community center, also in Madrid. Dr Ballester was awarded an Alicia Koplowitz Advanced Fellowship in 2009 to attend the 2-year child and adolescent psychiatry fellowship at University of Pittsburgh. He completed his first year as a resident at Maimonides Medical Center in Brooklyn, New York. He reports no conflicts of interest concerning the subject matter of this content.

Acknowledgement: Thanks to James Phelps, MD, Bipolar Disorder Section Editor for Psychiatric Times, for his guidance and review of this material.

References:

1. Ballester J1, Goldstein B, Goldstein TR, et al. Prospective longitudinal course of aggression among adults with bipolar disorder. Bipolar Disord. 2013;Dec 23. [Epub ahead of print]. See: http://onlinelibrary.wiley.com/doi/10.1111/bdi.12168/abstract.
2. Fazel S, Lichtenstein P, Grann M, et al. Bipolar disorder and violent crime: new evidence from population-based longitudinal studies and systematic review. Arch Gen Psychiatry. 2010;67:931-938.
3. Fazel S, Lichtenstein P, Frisell T, et al. Bipolar disorder and violent crime: time at risk reanalysis. Arch Gen Psychiatry. 2010;67:1325–1326. Erratum in: Arch Gen Psychiatry 2011;68:123.