Research Snapshot: Blood flow in the brain and core mood symptoms in youth with bipolar disorder

What you need to know

What is this research about?

Bipolar disorder has been linked to cardiovascular health and problems with blood vessels in general. Blood flow in the brain, or cerebral blood flow (CBF), is not only an indicator of brain health but also of a person’s overall vascular health. One may wonder how this relates to bipolar disorder. There have been numerous studies demonstrating abnormal CBF in adults with bipolar disorder, especially in relation to mood symptoms. However, thus far, little is known about CBF in youth with bipolar disorder. This study focuses on increasing knowledge about the connection between mood and CBF in this population.

What did the researchers do?

The study recruited 81 youth with bipolar disorder between 13 and 20 years old. The researchers looked at CBF in specific areas of the brain using magnetic resonance imaging and examined how it varies based on the severity of the core symptoms of depression and mania.

What did the researchers find?

The researchers found that greater severity of sad mood and anhedonia (the inability to feel pleasure) was associated with decreased CBF. This effect was particularly noted in the area of the brain called the anterior cingulate cortex, or ACC. This region, which helps process and regulate emotions, is known to be relevant to bipolar disorder, based on prior findings of structural and functional abnormalities.

The researchers noted that while these are early findings, they highlight the potential value of focusing on the ACC when studying sad mood and anhedonia.

While there are differences between youth and adults with bipolar disorder, this study shows that CBF is relevant to mood symptoms even in young people. It also shows that the ACC is a key brain region in youth with bipolar disorder, as it is in adults.

Limitations of the research

The researchers point to several limitations of their study. First, they focused on only three brain regions and suggest that future studies should look at other regions as well. Because the study was based on a single CBF measurement, the researchers were not able to look at the timing or mechanisms underlying the relationship between CBF and mood symptoms. Also, the researchers excluded youth who were experiencing acute mania at the time of the magnetic resonance imaging scans, which limited their ability to examine the relationship between CBF and manic symptoms.

How can you use this research?

This is the first study to look at the link between individual mood symptoms and regional CBF in any age group with bipolar disorder. These results need to be confirmed in larger studies. This research can be used to guide other research about the underlying causes of specific mood symptoms, which may have different causes.

With continued research, CBF could be integrated into treatment studies as an objective way to measure treatment response or a way of selecting specific treatments for a given individual. Such research can help answer questions about why certain people improve, or do not improve, with treatment. Similarly, this type of research may one day inform decisions about the likelihood that an individual will respond to one treatment or another.

About the researchers

Mikaela K. Dimick1, Simina Toma2, Bradley J. MacIntosh2, Anahit Grigorian3, Lisa Fiksenbaum4, Eric A. Youngstrom5, Andrew D. Robertson6, Benjamin I. Goldstein7

  1. Centre for Youth Bipolar Disorder, Centre for Addiction and Mental Health (CAMH), Toronto, Canada; University of Toronto, ON, Canada.
  2. University of Toronto, Canada; Sunnybrook Health Sciences Centre, Toronto, ON, Canada.
  3. Centre for Youth Bipolar Disorder, Centre for Addiction and Mental Health (CAMH), Toronto, ON, Canada.
  4. Sunnybrook Health Sciences Centre, Toronto, ON, Canada.
  5. University of North Carolina at Chapel Hill and Helping Give Away Psychological Science, Inc., Chapel Hill, NC, USA.
  6. University of Waterloo, Waterloo, ON, Canada.

See more related to