Research shows that longstanding depression alters the brain -- treatment may require different approaches depending on not just the severity of the depression but also on its longevity:
Is clinical depression always the same illness, or does it change over time?
New brain imaging research from the Centre for Addiction and Mental Health (CAMH) shows that the brain alters after years of persistent depression, suggesting the need to change how we think about depression as it progresses.
The study, led by senior author Dr. Jeff Meyer of CAMH's Campbell Family Mental Health Research Institute, is published in The Lancet Psychiatry.
The research shows that people with longer periods of untreated depression, lasting more than a decade, had significantly more brain inflammation compared to those who had less than 10 years of untreated depression. In an earlier study, Dr. Meyer's team discovered the first definitive evidence of inflammation in the brain in clinical depression.
This study provides the first biological evidence for large brain changes in long-lasting depression, suggesting that it is a different stage of illness that needs different therapeutics - the same perspective taken for early and later stages of Alzheimer's disease, he says.
"Greater inflammation in the brain is a common response with degenerative brain diseases as they progress, such as with Alzheimer's disease and Parkinson´s disease," says Dr. Meyer, who also holds Canada Research Chair in the Neurochemistry of Major Depression. While depression is not considered a degenerative brain disease, the change in inflammation shows that, for those in whom depression persists, it may be progressive and not a static condition.
More information: Elaine Setiawan et al, Association of translocator protein total distribution volume with duration of untreated major depressive disorder: a cross-sectional study, The Lancet Psychiatry (2018). DOI: 10.1016/S2215-0366(18)30048-8 [doi.org]