Bipolar Disorder consists of episodes of either mania or hypomania and of depression. There are a variety of bipolar disorders, categorized depending on whether someone has more episodes of mania or depression and how frequent these bouts are. Treatments including valproic acid can aid in alleviation of these symptoms.
What Is Valproic Acid?
Valproic acid is an anticonvulsant, meaning it is also used to treat seizures. It is found along with sodium valproate in the drug Divalproex, which is one of only a few anticonvulsants that are approved by the FDA for the treatment of mania in bipolar disorder.
Mechanism of Action
Bipolar disorder is thought to be due to imbalances in the brain of chemical substances, called neurotransmitters. One of these neurotransmitters—glutamate—is involved in "excitatory" mechanisms in the brain and can be increased during periods of bipolar mania. Valproic acid is thought to work by decreasing the ability of glutamate to pass excitatory signals, returning their levels to normal. It may also work by increasing the actions of the neurotransmitter GABA, which normally inhibits glutamate signaling. Additionally, valproic acid has been found to modify the actions of a chemical called arachidonic acid that has a number of functions in maintaining proper signaling in the brain and may be disrupted in people with bipolar disorder.
Action on Bipolar Symptoms
Manic episodes include irritability, elevated mood and disturbances of thoughts and words. A review by Charles Bowden in the June 2009 issue pf Bipolar Disorders, discusses how valproic acid is very effective in episodes of acute mania, more so than some other treatments for this stage, including lithium, antipsychotics and other anticonvulsants. Those who respond to valproic acid at this stage also respond favorably to longer term treatment. Although it is not indicated for acute bipolar depression, some trials, including one by S. Nassir Ghaemi in the December 2007 issue of Journal of Clinical Psychiatry, show it may be useful for this symptom, especially for those with rapid cycling bipolar disorder.
Side Effects
As with many medications, there can be a number of side effects of valproic acid. This is thought to be because it acts on a number of different systems both in the brain and the rest of the body. Side effects include increased appetite and weight gain; gastrointestinal problems such as nausea, vomiting and abdominal cramps; hair loss; drowsiness; and tremors. Long term use can detrimentally affect liver and pancreatic function, and there are warnings to this end on the prescribing information for any form of valproic acid.
Medication Combinations
Valproic acid can be used alone or in combination with other mood stabilizers including lithium, especially for cases that aren’t completely helped with valproic acid alone. This is especially useful, as it means both drugs can be used at lower doses, thus possibly reducing side effects. It is also used in combination with antipsychotics, to aid in the treatment of acute mania, and benzodiazepines, to help in agitation.
References
- “Stahl’s Essential Psychopharmacology. Neuroscientific Basis and Practical Applications. Digital Edition;” Stephen M. Stahl; 2008
- “Brain Research Reviews;” Bipolar Disorder and Mechanisms of Action of Mood Stabilizers. Stanley Rapoport; October 2009
- “Bipolar Disorders;” Anticonvulsants in Bipolar Disorders: Current Research and Practice and Future Directions; Charles Bowden; June 2009
