It has long been known that emotional experiences leave lasting physiological effects, but what has only recently been measured is the degree to which they do. A lot of research is now being done around depression – what it looks like in the brain and how the brain is changed – and one of the most recent findings was that the inflammation caused by chronic depression can permanently alter your brain.
A study was published on February 26th, in The Lancet Psychiatry by Elaine Setiawan, PhD and her research team. The method incorporated in this study was cross-sectional. Participants were aged between 18 and 75 years old and were recruited from the Toronto area and the Centre for Addiction and Mental Health. Aside from the ‘control’ people (those without depression), the research team recruited people who had major depressive episodes secondary to major depressive disorder. In fact, the participants had to score 100% on the Hamilton Depression Rating Scale to be enrolled, as well as be nonsmokers and medication free, or, at least, be taking a stable dose of medication 4 weeks prior to their PET scan. The participants also had to have no history of alcohol abuse, autoimmune disorder, neurological illnesses and severe medical problems (and they must have been cured of any acute medical problems at least 2 weeks prior to their PET scan).
The research team scanned three primary regions of the participants’ brains – their prefrontal cortex, anterior cingulate cortex and insula – as well as 12 subregions to measure TSPO V, a translocator protein that’s involved in the moderation of inflammation. The team also investigated both the total duration of depression and duration of antidepressant treatment as predictor variables of TSPO V to assess their significance. TSPO V was 29-33% greater in the prefrontal cortex, anterior cingulate cortex and insula of the participants who had untreated major depressive disorder for 10 years or longer, when compared to those who had the disorder for 9 years or less — strongly suggesting that the former group of participants had entered a different phase of their illness. Those with treated depression had a yearly increase in microglial activation. When the participants who had gone 10 years without treatment were finally given treatment, no increase in microglial activation was found.
The researchers’ findings might lead to depression being taken more seriously as a disease, which, in turn, will lead to better treatments being developed and more ways to quickly diagnose the illness. It could also lead to depressives becoming more proactive in treating themselves, understanding that the longer they remain in their mental state, the tougher it will be for them to get out of it.
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