A Silvery Solution: Lithium’s Mechanism in Treating Bipolar Disorder

    Originally used as a treatment in the nineteenth century for recurrent depression, lithium has grown to be the most recommended treatment for bipolar disorder (BD) because of its anti-manic effects and decrease in suicide ideation. As described in the DSM-V, bipolar disorder is distinguished into two types: BD-I and BD-II. For BD-I, a person experiences at least one manic episode, which includes extreme ideas of grandiosity, elevated energy levels, and severe mood disturbances. Similarly, BD-II symptoms include less severe manic episodes in addition to major depressive episodes that disrupt daily life. Because of this disorder’s debilitating nature, lithium has continued to be used as a primary treatment even though we do not have a complete understanding of its mechanisms within the brain. As a result, this paper reviews major publications about lithium research and its clinical effects to propose potential mechanisms for this medication.

    Attempting to understand its mood-stabilizing properties, it has been suggested that lithium has neuroprotective effects, ranging from aiding in apoptosis, neurogenesis, and synaptic plasticity by decreasing the amount of oxidative stress, or severe damage, on the mitochondria. Moreover, lithium is involved in biological pathways that slow down DNA degradation, increase glial, or structural, cells, and remyelinate, or reinsulate, neural pathways, especially in the hippocampus. As such, lithium plays a crucial role in neuroplasticity by strengthening neural connections and regulating the brain’s neurons, which suggests that lithium helps rewire and maintain a bipolar individual’s brain activity to decrease extreme mood changes. In addition to aiding in neuroplasticity, lithium has been observed to positively impact the release of certain neurotransmitters. Most notably, levels of dopamine, GABA, and glutamate, which generally regulate our emotions, are stabilized. Since most forms of bipolar disorder exhibit a disturbance in several neurotransmitter pathways, this alteration of neurochemistry also gives us further insight into the mechanisms of lithium.

    Despite these benefits, it is important to note that this treatment comes with significant potential side effects, such as impaired kidney function, elevated calcium levels, weight gain, and lithium intoxication. Like any prescription medication, prescribers must consider the pros and cons of each treatment and order routine exams to ensure the best care for their patients. As such, having a better understanding of lithium may allow us to isolate the benefits of this drug and reduce the severity and possibly presence of some of these side effects.