Mood swings may be one of the most difficult symptoms of bipolar disorder to put up with, yet a new study carried out in May 2016 has shown that changing moods can also be toxic to brain cells and can exert a negative effect on the connective ability of neurons.
The study, carried out by Fabio Klamt and other researchers at the Laboratory of Cellular Biochemistry at the Federal University of Rio Grande do Sul and Flavio Kapczinski at the Laboratory of Molecular Psychiatry at the HCPA Hospital in Brazil, showed that the severity and frequency of mood episodes in persons with bipolar disorder is directly linked to changes in the brain, including a reduction in volume and neuroprogression.
Neuroprogression is a term used to define the pathological reorganization of the central nervous system which occurs in serious mental disorders. In bipolar disorder, repeated mood episodes promote the rewiring of the brain, which in turn leads to greater vulnerability to stress. The process can impair vital functions, including memory and learning. It can also affect the brain’s ability to recover from damage.
A previous study had already shown that markers linked to inflammation, oxidative stress and specific proteins related to neuron growth and survival are linked to mood episodes in patients with bipolar disorder. Another study, meanwhile, has shown that very low levels of proteins that signal other parts of the cell are present in persons with bipolar disorder.
The new research is considered groundbreaking because it showed that the blood of patients with bipolar disorder is actually toxic to brain cells, affecting the ability of neurons to connect. The researchers discovered this by exposing specific neurons to blood serum from patients with bipolar disorder, or to blood serums from patients without the disorder. They found that the neurons which had been exposed to the blood of persons with bipolar disorder had significantly less neurites.
There was a big difference in neurite density between early-stage and late-stage patients with bipolar disorder, with the latter showing far lower neurite levels. This suggests that the greater the frequency of mood episodes, the more changes are produced in cells which affect the brain’s ability to adapt to environmental changes, stress and inflammation. The study is the first to reveal the effects of blood toxicity in bipolar disorder patients in vitro. The next step, say the scientists, is to develop new medication which can protect cells from the toxic effect of blood.
In addition to difference in toxicity, other brain differences have been found in past research. It is known, for instance, that the brain of patients with bipolar disorder have lower levels of EGR3 — a protein that helps us cope with stress and environmental changes. Lower levels of Omega-3 have also been found in those with bipolar disorder, whose brains are more sensitive since their neurons are incredibly quick to respond — even when stimulation levels are low. The mitochondria of their cells are more active. In fact, it is thought that the manic stage arises in patients when cells are overly stimulated and simply cannot cope, leading them to "shut down" (and the person to enter a depressive phase).
Scientists expect that new advances will enable them to make new discoveries that will lead to better, more effective treatments for bipolar disorder. It is important to note that there is no single cause for bipolar disorder, but rather, several factors which can contribute to its development. Although bipolar disorder can be more prevalent in specific families, genes do not tell the whole story, since there are many cases of identical twins in which only one twin has the disorder. Since their genetic make-up is identical, it would make sense for both twins to have bipolar disorder if the causes were purely genetic.
Research also shows that bipolar disorder does not arise because of one sole gene; rather, it may develop because of a combination of genes, as well as environmental factors. Scientists therefore have a tough road ahead of them in so far as prevention is concerned. However, findings such as those indicated above are holding great promise for reducing the symptoms and negative effects of bipolar disorder, a disorder which affects around 5.7 million people in the United States.