Scientists Identify Five Different Brain Activity Patterns Linked to Depression

Depression may involve five distinct patterns of brain activity, despite people receiving the same diagnosis, according to a study from the University of Helsinki.

Researchers analysed brain activity in 263 people with major depressive disorder and 75 healthy participants. Using magnetoencephalography (MEG), they examined functional connectivity, which describes how strongly different brain regions work together and communicate.

The analysis identified five groups of people with depression based on differences in the strength and frequency of connections between brain regions. All five groups differed from healthy participants, but the patterns were not the same.

One group had fairly strong connectivity and showed more severe depression, anxiety, repetitive negative thinking and reduced ability to function. Another group had generally weak connectivity but milder symptoms.

A third group showed weak connectivity across large areas of the brain and had more prominent symptoms of post-traumatic stress disorder. A fourth group had a mixture of weak and strong connections and was characterised by depression severity, substance abuse and poor wellbeing.

The fifth group had the strongest connectivity among the depression groups. Substance abuse was more prominent in this group, while traumatic symptoms were less pronounced.

Researchers said these differences may help explain why earlier studies of depression have produced conflicting findings. People with the same diagnosis may have very different changes in brain activity.

MEG allowed researchers to measure brain activity with millisecond-level precision, providing a detailed view of how brain regions communicate over time.

The findings suggest that depression may not be biologically identical in everyone. However, brain measurements cannot currently be used to select the best treatment for an individual patient.

Researchers said future studies could explore whether combining brain activity patterns with symptoms may help doctors identify suitable treatments more quickly and reduce reliance on trial and error.

REFERENCE: Liu, W., et al. (2026) Magnetoencephalography oscillation-based functional connectivity identifies clinically relevant depression phenotypes. Nature Mental Health. DOI: 10.1038/s44220-026-00723-4. https://www.nature.com/articles/s44220-026-00723-4