Most people experience emotional ups and downs during the course of their lifetimes. Depending on either the events happening in our lives, or hormonal changes during different developmental stages, a typical person could experience quite a bit of mood fluctuations. But patients with bipolar disorder experience greater and more frequent mood swings than the typical person. Unfortunately, the mechanism of this disorder is not yet fully understood and therefore there are no physiological tests that could help diagnosing the disorder. And since it is sometimes very difficult to tell the differences between normal mood swings and symptoms of bipolar disorder, many people suffer for years before the illness is properly diagnosed and receive treatments.
There are three main hypotheses on the mechanism of the mood stabilizers that are widely recognized and greatly investigated by scientists, the “myo-inositol depletion hypothesis”, the “GSK-3 inhibition hypothesis” and the“arachidonic acid cascade hypothesis”. In the paper we read for this week, the authors focus on the AA cascade hypothesis and discuss the possible
mechanism for the action of mood stabilizers such as lithium, carbamazepine, sodium valproate and lamotrigine. Since some of these four drugs are channel blockers, and lithium is in its ionized form, they all have different properties which increase the difficulty to explain all four of them through one common hypothesis.
Arachidonic acid is a polyunsaturated fatty acid that is esterified predominantly in the stereospecifically number 2 position of brain membrane phospholipids. When released by a phospholipase A2 (PLA2), AA has multiple biological effects including neurotransmission, membrane excitability, long-term potentiation, gene transcription, membrane fluidity, neurite outgrowth, cerebral blood flow, sleep, memory and behavior. And according to the paper, the experiments show the four different drugs that are known to have positive effects on treating bipolar disorder all down regulate the AA cascade and even though they work at different levels of the cascade, their effects all contribute an overall reduction of the AA turnover rate. These are promising results which will encourage the scientists to look into the this AA cascade even further in order to get a better understanding of what actually goes in terms of bipolar disorder. And hopefully come up with better treatment which will get rid of some of the nasty side effects of these current medications.
It is very difficult to imagine how it must feel like to live with suc
h a disorder, or to live with someone suffering from it. Although I am not an expert in psychiatry, personally, I believe that nature is in favor of everything being balanced. For example, human body prefers to retain hemostasis, any fluctuations of our body temperature, hormone levels, and even neurotransmitters could potentially cause major defects. It should be the same for our mind as well. A healthy mind, in my opinion, should be in a fairly stable mental state which one can function at his/her best.
Bright Side, Dark Side- Bipolar Disorder
