Lithium is a small, naturally occurring element that has a long history of use as a medication in mental health care. In psychiatry, it is primarily valued as a mood stabilizer that can help prevent mood swings in bipolar disorder and, in some cases, augment antidepressant treatment. Unlike many other psychiatric drugs, lithium does not create a rapid emotional shift; instead, it works gradually to reduce the intensity and frequency of manic, hypomanic, and depressive episodes. It also has a unique role in reducing suicide risk for some people with mood disorders.
How lithium works
Lithium’s exact mechanism is not fully understood, and it likely acts through multiple biological pathways. It is known to influence signaling in brain cells, including pathways that regulate mood-related neurotransmitters and intracellular messengers. Some proposed actions include modulation of second messenger systems, effects on neurotrophic factors that support neuron health, and stabilization of neural circuits involved in emotion regulation. Because mood disorders involve complex brain networks, lithium’s broad, gradual effects can help dampen extreme mood shifts and promote steadier thinking and behavior over time.
Common uses and conditions treated
While lithium can be used in several contexts, its primary indications in contemporary practice include:
- Bipolar disorder (bipolar I and bipolar II): to prevent manic and depressive episodes and to reduce mood fluctuations.
- Suicidality reduction: evidence suggests that lithium can lower the risk of suicide in some individuals with mood disorders.
- Major depressive disorder: used as an augmentation strategy when antidepressants alone do not provide adequate relief (often in combination with an antidepressant).
- Other mood-related conditions or specialty uses: occasionally employed in certain inflammatory or neurodegenerative contexts in research or specialized clinical settings, but these are less common.
Because lithium’s effects develop over weeks to months, it is generally not the first choice for rapid relief of acute symptoms. It is typically part of a longer-term plan that includes regular monitoring and follow-up with a clinician.
Typical dosages and how dosing is determined
Dosage is individualized and guided by regular blood level testing, kidney function, thyroid function, age, body weight, and how well symptoms respond. General guidelines include:
- Starting: many clinicians initiate treatment with about 300 mg of immediate-release lithium two to three times daily (total around 600–900 mg per day), or an equivalent dose in slow-release form.
- Maintenance: total daily doses commonly range from 900 to 1800 mg, divided into two or more doses, though some people may take more or less depending on levels and tolerance.
- Target blood levels: for maintenance, trough (before the next dose) levels are usually kept around 0.6–1.0 mEq/L; during an acute manic episode, higher levels (often 0.8–1.2 mEq/L) may be used under careful supervision.
- Time to steady state: it can take several days to weeks for lithium levels to stabilize and for mood effects to become evident.
Form choices (immediate-release vs. sustained-release) influence how the drug is dosed and how tolerability is managed. Patients with reduced kidney function or older adults often require lower doses and closer monitoring.
Potential side effects and monitoring
Side effects are common, especially when starting therapy, and many subside over time. Common, usually mild effects include:
- Gastrointestinal upset (nausea, diarrhea), thirst, and increased urination
- Tremor and mild cognitive dulling
- Weight gain, hair changes, and acne in some individuals
More serious concerns require prompt medical attention and regular monitoring:
- Kidney function changes and risk of nephrogenic diabetes insipidus
- Thyroid changes, including hypothyroidism
- Electrolyte imbalances and dehydration-related toxicity risk
- Toxicity signs such as persistent vomiting, severe tremor, confusion, ataxia, slurred speech, seizures, or blurred vision
Monitoring typically includes:
- Regular blood lithium level checks (often about 12 hours after a dose) to ensure levels remain within the target range
- Kidney function tests (creatinine, BUN)
- Thyroid function tests (TSH, free T4), as thyroid problems are a known risk with long-term use
- Pregnancy testing for people who could become pregnant and, for those planning pregnancy, careful risk-benefit discussion
Consistent hydration and a stable intake of salt are important since dehydration or significant salt loss can raise lithium levels and increase toxicity risk. If you become unexpectedly ill with vomiting or diarrhea, or if you’re sweating heavily, you should contact your clinician promptly.
Interactions with other medications
Many medicines and substances can affect lithium levels or increase the risk of side effects. Important interactions include:
- Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen, naproxen, and certain over‑the‑counter medications can raise lithium levels and toxicity risk. Use alternatives when possible and discuss any planned NSAID use with your clinician.
- Diuretics, especially thiazide diuretics, can raise lithium levels and toxicity risk; some loop diuretics may have a similar effect
- ACE inhibitors and certain ARBs (drugs that affect kidney function) can alter lithium clearance
- Other psychotropic medications—like certain antidepressants, antipsychotics, or anti-manic agents—may require dose adjustments or closer monitoring due to interactions or changes in mood risk
- Medications that affect salt and water balance, or that cause dehydration, can indirectly influence lithium levels
Always tell your healthcare provider about every medicine you take, including over-the-counter products and supplements, before starting lithium or making changes to your regimen. In some situations your clinician may adjust the lithium dose, switch formulations, or implement closer lab monitoring.
Important considerations for patients
Several practical points help maximize safety and effectiveness when using lithium:
- Adherence is crucial. Do not adjust or stop lithium without talking to your clinician, even if you feel well. Sudden changes can destabilize mood or cause toxicity if levels rise when you re-dose.
- Regular labs and follow-up visits are part of treatment. Keep a consistent schedule for blood tests and discuss any new symptoms promptly.
- Hydration and salt balance matter. Sudden changes in fluid intake or vomiting, diarrhea, or heavy sweating can affect lithium levels.
- Be mindful of pregnancy and family planning. Lithium carries known risks in pregnancy, particularly to the developing heart in early pregnancy, so a careful plan with obstetric and psychiatric care is essential.
- Education and safety. Learn signs of possible toxicity (nausea, tremor, confusion, severe thirst, drowsiness) and seek urgent care if these occur, especially after dehydration or illness.
- Work, school, and activities. Some people notice mild cognitive slowing or tremor; discuss coping strategies with your clinician if these interfere with daily life.
Inquiries about starting or continuing lithium, or about how it interacts with other therapies, should be addressed in partnership with a healthcare professional. If you’d like to read more from reputable sources, see the following resources:
External information you may find helpful:
Discussion with your medical team is essential to tailor lithium therapy to your individual needs. If you’re considering lithium or evaluating its role in your treatment plan, ask about target blood levels, monitoring schedules, potential side effects, and how to manage interactions with other medications you take.
