Understanding Mood Stabilizers Beyond a Simple Pair
When people ask, 'What are the two mood stabilizer drugs?', they are often referring to the most well-known and historically significant medications used to treat mood disorders like bipolar disorder. Mood stabilizers are a class of psychiatric medications that help control mood swings, preventing the extreme highs (mania or hypomania) and lows (depression) [1.10.4]. While the field is extensive, the two drugs that form the historical foundation of this class are Lithium and the anticonvulsant Valproic Acid (also called valproate or divalproex sodium) [1.2.3, 1.3.5]. However, limiting the discussion to just two drugs would be a disservice to the advancements in pharmacology. Today, mood stabilizers fall into three main categories: lithium, anticonvulsants, and atypical antipsychotics [1.4.5].
The Foundational Pillars: Lithium and Valproic Acid
Lithium: The Gold Standard
Approved for treating mania in 1970, lithium is often considered the 'gold standard' mood stabilizer [1.2.5, 1.4.2]. It is a naturally occurring element that is effective in treating acute mania, preventing recurrent manic and depressive episodes, and reducing the risk of suicide in people with bipolar disorder [1.2.2, 1.5.4]. The exact mechanism of how lithium works is not fully understood, but it is believed to influence several neurotransmitter systems in the brain, including serotonin and dopamine, and offer neuroprotective effects [1.10.3].
Treatment with lithium requires careful and regular monitoring of blood levels to ensure it remains within a narrow therapeutic range. Levels that are too low will be ineffective, while levels that are too high can be toxic [1.11.1]. Common short-term side effects can include nausea, tremor, increased thirst, and frequent urination [1.5.3]. Long-term risks can involve the kidneys and thyroid, necessitating ongoing medical supervision [1.11.1, 1.5.2].
Valproic Acid: The Key Anticonvulsant
Valproic acid (brand name Depakote) is an anticonvulsant medication that was originally developed to treat seizures but was found to be highly effective at managing manic episodes in bipolar disorder [1.3.3, 1.4.2]. It is particularly useful for patients with mixed episodes (experiencing symptoms of mania and depression simultaneously) or rapid-cycling bipolar disorder [1.3.2]. Like lithium, its exact mechanism is complex, but it is known to increase the levels of the calming neurotransmitter GABA in the brain [1.10.3].
Common side effects include drowsiness, dizziness, weight gain, and hair loss [1.6.1, 1.6.2]. More serious risks, though less common, include damage to the liver and pancreas, and it carries a significant risk of birth defects if taken during pregnancy [1.6.1, 1.11.3]. Therefore, its use in women of childbearing potential is strictly regulated [1.11.3].
The Broader Spectrum of Mood Stabilizers
While lithium and valproic acid are the two classic answers, several other medications are crucial for stabilizing mood.
Other Anticonvulsants
- Lamotrigine (Lamictal): This anticonvulsant is particularly effective at preventing the depressive episodes of bipolar disorder, though it is less helpful for mania [1.3.4]. Treatment must be started at a very low dose and increased slowly to minimize the risk of a serious skin rash [1.3.4].
- Carbamazepine (Tegretol): Another anticonvulsant, carbamazepine is effective for mania and is sometimes used when patients do not respond well to lithium [1.3.5]. It can interact with many other medications and requires blood monitoring.
Atypical Antipsychotics
The newest class of drugs with mood-stabilizing properties is the second-generation, or 'atypical,' antipsychotics [1.3.5]. Many are now FDA-approved for treating acute mania, bipolar depression, or as maintenance treatment, either alone or in combination with other mood stabilizers [1.2.3]. They work by influencing dopamine and serotonin receptors [1.4.1].
Examples include:
- Quetiapine (Seroquel) [1.2.2]
- Olanzapine (Zyprexa) [1.2.2]
- Aripiprazole (Abilify) [1.2.2]
- Risperidone (Risperdal) [1.2.2]
- Lurasidone (Latuda) [1.2.3]
These agents have expanded the treatment toolkit significantly, but they also come with their own side effect profiles, most notably the risk of weight gain and metabolic changes like increased blood sugar and cholesterol [1.4.1].
Comparison of Common Mood Stabilizers
| Medication | Primary Use | Common Side Effects | Key Monitoring Needs |
|---|---|---|---|
| Lithium | Mania, Maintenance, Bipolar Depression [1.2.3, 1.3.2] | Tremor, thirst, nausea, weight gain, cognitive fog [1.5.3, 1.11.1] | Regular blood tests (lithium levels, kidney & thyroid function) [1.11.1] |
| Valproic Acid | Acute Mania, Mixed States [1.3.2, 1.3.4] | Drowsiness, weight gain, hair loss, GI upset [1.6.1, 1.11.4] | Liver function tests, platelet counts [1.6.1, 1.11.3] |
| Lamotrigine | Bipolar Depression, Maintenance [1.2.3, 1.3.4] | Headache, dizziness, nausea, skin rash [1.3.4, 1.11.4] | Slow dose titration to monitor for serious rash [1.3.4] |
| Quetiapine | Acute Mania, Bipolar Depression [1.2.3] | Drowsiness, dry mouth, weight gain, metabolic changes [1.9.1] | Blood pressure, weight, blood glucose, cholesterol [1.4.1] |
Conclusion: Personalized Treatment is Key
The question 'What are the two mood stabilizer drugs?' opens the door to a much larger and more nuanced conversation. While lithium and valproic acid are the historic and foundational agents, the modern treatment of mood disorders involves a wide array of medications from different classes, including other anticonvulsants and atypical antipsychotics [1.2.2].
The choice of medication is a highly individualized decision made between a patient and their healthcare provider. It depends on the specific symptoms being targeted (mania vs. depression), the patient's medical history, and their ability to tolerate potential side effects [1.2.2]. Effective management of a mood disorder is a long-term commitment that often involves a combination of medication, therapy, and lifestyle adjustments to achieve stability and well-being.
For more information, a great resource is the National Institute of Mental Health (NIMH): https://www.nimh.nih.gov/health/topics/bipolar-disorder
