Cellular energy changes may help detect early-stage major depression

Researchers may have discovered a new way to diagnose and treat major depression at the earliest stage of the condition, giving patients the best opportunity for recovery.

University of Queensland researchers, in collaboration with the University of Minnesota, analysed levels of adenosine triphosphate (ATP) – known as the "energy currency" molecule – in the brain and blood cells of young people with depression.

Associate Professor Susannah Tye from UQ's Queensland Brain Institute (QBI) said this was the first time patterns in these fatigue molecules had been discovered in both the brain and blood stream of young people with major depressive disorder (MDD).

This suggests that depression symptoms may be rooted in fundamental changes in the way brain and blood cells use energy.

Fatigue is a common and hard-to-treat symptom of MDD, and it can take years for people to find the right treatment for the illness.

There has been limited progress in developing new treatments because of a lack of research and we hope this important breakthrough could potentially lead to early intervention and more targeted treatments."

Dr. Susannah Tye, Associate Professor, UQ's Queensland Brain Institute

During the study, a team at the University of Minnesota collected blood samples and scans from 18 people aged 18-25 years, who had been diagnosed with MDD.

These were then analysed by the QBI team and compared with samples from participants who did not have depression.

QBI researcher, Dr Roger Varela said they found cells in people with depression produced more energy molecules when resting, but had a reduced ability to increase energy production under stress.

"This suggests cells may be overworking early in the illness, which could lead to longer-term problems," Dr Varela said.

"This was surprising, because you might expect energy production in cells would be lower for people with depression.

"It suggests that in the early stages of depression, the mitochondria in the brain and body have a reduced capacity to cope with higher energy demand, which may contribute to low mood, reduced motivation and slower cognitive function."

Dr Varela hopes this research will help de-stigmatise depression.

"This shows multiple changes occur in the body, including in the brain and the blood, and that depression impacts energy at a cellular level," he said.

"It also proves not all depression is the same; every patient has different biology, and each patient is impacted differently.

"We hope this research will help lead to more specific and effective treatment options."

The study was led by the University of Minnesota's Katie Cullen MD, and the imaging technique used to measure ATP production in the brain was developed by Professors Xiao Hong Zhu and Wei Chen. 

The research is published in Translational Psychiatry.