The Young and the Old: A Look into the Bipolar Brain

A recent study on Bipolar Disorder (BD) conducted by psychologists at the Dresden University of Technology (TUD) has found that BD could impair proper brain development in adolescents and that repeated episodes may accelerate structural brain decline. By conducting a systematic review of 11 longitudinal studies, the team at the Chair of Clinical Psychology and Behavioral Neuroscience observed the loss of brain volume of BD patients as compared with healthy patients over time.

The human brain is an incredibly complex organ that continues to develop well after birth, throughout adolescence, and finally reaching maturity in early adulthood. As a part of the natural aging process, the human brain will then begin to slowly lose volume and structure. The brain is therefore an organ that is extremely vulnerable to change, especially during childhood and adolescence.

Some mental conditions such as Bipolar Disorder (BD), a progressive mental disorder, can have substantial impacts on brain development. While BD is already associated with structural brain changes, it is not clear how these alterations arise over time. This is because most studies on BD brain structure have been cross-sectional studies, which look at many subjects in one single point in time. The first psychopathological symptoms in later bipolar patients often occur in childhood and adolescence, so it is particularly interesting to study bipolar disorder in early stages (adolescence) and the later course of the illness (adulthood).

In a systematic review, Dr Katharina Förster and her Team at the Chair of Clinical Psychology and Behavioral Neuroscience therefore concentrated on results from eleven longitudinal imaging studies with a total of 329 bipolar patients and 277 healthy control subjects. They were particularly interested in how the grey matter and the volume of the brain change over time in connection with the course of bipolar disorder.

After analyzing these studies all together, a few important observations were made. Firstly, they noticed a positive correlation of the number of mood episodes in adult patients with the amount of structural loss over time. In other words, the more severe BD is in a patient, the faster their brain ages. They also found that adolescents with BD experience stunted brain development. While brain volume should be increasing in healthy adolescents, BD adolescents showed stable or even decreasing brain volume over time. A part of the adolescent brain specifically affected by volume loss is the amygdala, a small almond-shaped mass that is associated with experiencing emotions.

The results suggest that adolescent onset is associated with specific brain structural changes. These brain structural changes could result from an interplay between brain maturation processes and the onset of bipolar disorder. The results also indicate that even these first episodes in adolescence are associated with structural changes in the brain.

Therefore, in clinical practice, adolescents and young adults who show evidence of developing bipolar disorder should be monitored over time and receive early individually planned treatment in favor of a 'wait and see' approach.

Original publication:
Förster, K*, Horstmann, RH*, Dannlowski, U, Houenou, J, Kanske, P. Progressive grey matter alterations in bipolar disorder across the life span – A systematic review. Bipolar Disord. 2023; 25: 443-456.
 https://doi.org/10.1111/bdi.13318
*equal contribution

Media inquiries:
Dr. Katharina Förster
Chair of Clinical Psychology and Behavioral Neuroscience
Dresden University of Technology
Tel.: +49 351 463-42165