Understanding Lithium and Its Role in Psychiatry
Lithium is a naturally occurring element that is used as a powerful mood-stabilizing medication in psychiatry [1.11.2]. It was the first drug to receive FDA approval for treating bipolar disorder (formerly manic depression) in 1970 and continues to be a first-line treatment choice for many clinicians [1.2.2, 1.2.4]. It works on the central nervous system to help balance brain substances that regulate mood and behavior, allowing individuals to have more control over their emotions [1.2.3, 1.2.5]. While its exact mechanism is still being studied, it is known to alter sodium transport in nerve and muscle cells and influence neurotransmitters like serotonin and dopamine [1.4.1, 1.4.5]. It is also believed to have neuroprotective effects, potentially increasing gray matter volume in the brain [1.4.1].
Primary Indication: Bipolar Disorder
The primary mental illness treated with lithium is bipolar disorder. It is approved for managing acute manic and mixed episodes, as well as for maintenance treatment to prevent the recurrence of these episodes in patients aged 7 and older [1.2.4].
- Manic Episodes: Symptoms of mania that lithium helps control include periods of feeling overly happy or "high," increased energy and self-esteem, reduced need for sleep, racing thoughts, and engaging in risky behaviors [1.2.1].
- Depressive Episodes: While highly effective for mania, lithium also has antidepressant effects and is used for the depressive episodes characteristic of bipolar disorder [1.3.4].
- Maintenance Treatment: As a long-term treatment, lithium reduces the frequency and severity of both manic and depressive episodes, providing mood stability [1.2.5]. It is the only mood stabilizer that has been shown to significantly reduce the risk of suicide [1.6.4].
Off-Label Uses for Lithium
Beyond its primary FDA-approved use, clinicians may prescribe lithium "off-label" for other conditions where it has shown potential benefits [1.2.1]. This means the FDA has not officially approved it for these specific uses, but there is evidence supporting its efficacy.
- Major Depressive Disorder (MDD): Lithium is often used as an adjunct (add-on) therapy for treatment-resistant depression. When an antidepressant alone is not effective, adding lithium can augment its effects [1.3.1, 1.3.2].
- Schizophrenia and Schizoaffective Disorder: It can be used to help manage mood symptoms and aggression in individuals with these conditions [1.3.3].
- Impulse Control Disorders: There is some evidence for its use in managing aggression and disorders of impulse control [1.3.3].
- Vascular Headaches and Neutropenia: Other off-label medical uses include treating certain types of headaches and low white blood cell counts (neutropenia) [1.3.2].
Side Effects and The Importance of Monitoring
Lithium treatment requires careful management due to its narrow therapeutic index—the dose required for therapeutic effect is close to the dose that can cause toxicity [1.2.2]. Regular blood tests are essential to ensure the lithium level in the blood is within a safe and effective range, typically between 0.6 and 1.2 mmol/L for maintenance [1.7.1, 1.9.1].
Common side effects can include:
- Increased thirst and urination [1.5.5]
- Hand tremor [1.5.5]
- Nausea, vomiting, or diarrhea [1.5.1]
- Weight gain [1.5.3, 1.8.1]
- Cognitive effects like feeling mentally slowed down [1.11.2]
Long-term use can pose risks to:
- Kidneys: Prolonged use can affect kidney function, which is why regular monitoring of kidney health is critical [1.8.2, 1.8.3].
- Thyroid: Lithium can lead to hypothyroidism (an underactive thyroid), which may require treatment with thyroid hormone [1.8.3, 1.8.4].
- Parathyroid: It can also affect the parathyroid glands, leading to changes in calcium levels [1.5.5].
Lithium toxicity is a serious medical concern and can be acute or chronic. Symptoms can include severe nausea, slurred speech, confusion, muscle twitching, and lack of coordination [1.5.1, 1.5.2].
Lithium vs. Other Mood Stabilizers
While lithium is a gold standard, several other medications are also used to treat bipolar disorder. These include anticonvulsants like valproic acid (Depakote) and lamotrigine (Lamictal), and atypical antipsychotics like quetiapine (Seroquel) and olanzapine (Zyprexa) [1.10.2].
| Feature | Lithium | Valproic Acid (Depakote) | Lamotrigine (Lamictal) |
|---|---|---|---|
| Primary Use | Bipolar mania & maintenance [1.2.4] | Bipolar mania & mixed episodes | Bipolar maintenance, especially preventing depression [1.10.3] |
| Suicide Prevention | Strong evidence for reducing suicide risk [1.6.4] | Less evidence compared to lithium | Not as established as lithium |
| Common Side Effects | Thirst, tremor, weight gain, kidney/thyroid issues [1.5.5] | Weight gain, liver issues, sedation | Skin rash (can be serious), dizziness |
| Monitoring | Frequent blood level monitoring required [1.9.1] | Blood level and liver function monitoring needed | Monitored for rash, but not typically for blood levels |
Studies have shown that lithium may be superior to other mood stabilizers in preventing self-harm and reducing the risk of rehospitalization [1.6.1, 1.6.5].
Conclusion
So, what mental illness takes lithium? The definitive answer is bipolar disorder. It remains a cornerstone of treatment for its effectiveness in controlling mania, stabilizing mood long-term, and uniquely reducing suicide risk [1.2.2, 1.6.4]. While its use requires careful medical supervision due to a narrow therapeutic window and potential side effects, its benefits are profound for many individuals. Its off-label applications in treating major depression and other conditions further highlight its importance in modern pharmacology [1.3.1].
For more information from an authoritative source, visit the National Institute of Mental Health (NIMH) page on Bipolar Disorder.
