Mood Stabilizers: What They Are and How Treatment Decisions Are Made

This guide covers the basics of mood stabilizers in bipolar disorder, where they’re a cornerstone of treatment: what the main options are, how they differ, and how decisions about them are made. Understanding these helps people take a fuller part in their own treatment.

What Mood Stabilizers Do

Mood stabilizers work by different mechanisms depending on the specific medication. What they have in common is that they help steady mood over time, easing or preventing highs, lows, or both, depending on the medication. The goal isn’t to stop you from feeling emotions; it’s to reduce the extreme swings of bipolar disorder.

The Main Options

Lithium is the oldest and one of the most studied mood stabilizers. It has strong evidence for preventing manic episodes; its effect on preventing depressive episodes is smaller and less certain. It can also lower the risk of suicide. Lithium requires regular blood monitoring because the blood level that helps and the level that can be toxic are closer together than with most medications. The APA and the NIMH both recognize that bipolar treatment is individualized — dependent on the subtype, the predominant symptom pattern, and the person’s history of prior treatment responses.

Valproate, in the form of divalproex sodium, is FDA-approved for treating manic episodes. Its benefit for long-term use (beyond 3 weeks) hasn’t been shown in controlled trials, so providers keep reassessing whether it’s still helping. It requires regular blood monitoring, has meaningful side effects including weight gain and sedation, and can cause serious birth defects and lower IQ in children exposed before birth, so it should not be used in people who are pregnant or who could become pregnant unless other medications have not worked or are not suitable.

Lamotrigine is FDA-approved for long-term treatment of bipolar I, to delay the next mood episode, including depression. Its effectiveness for treating a mood episode that’s already happening hasn’t been established. It is generally well-tolerated, but it can rarely cause a serious skin reaction (Stevens-Johnson syndrome), so your provider starts it carefully and will ask you to report any rash right away.

Atypical antipsychotics — including quetiapine, lurasidone, olanzapine, aripiprazole, and others — have evidence for acute mania, bipolar depression, or both, depending on the medication, and have become increasingly used in bipolar disorder treatment, sometimes alongside traditional mood stabilizers. Older (typical) antipsychotics, such as haloperidol, are still used for acute mania, but guidelines rank them behind newer options because of safety and side-effect concerns, and they’re used less often long term because they can cause movement side effects.

How Treatment Decisions Are Made

No single medication is right for everyone with bipolar disorder. The decision involves weighing evidence for the specific presentation (Bipolar I vs. II, mania-predominant vs. depression-predominant, rapid cycling), the person’s history of prior treatment responses, co-occurring conditions, medication tolerability and side effect profile, lifestyle factors including pregnancy planning, and the person’s own preferences and values.

The Long-Term Relationship

Protecting sleep and keeping a regular routine are important parts of managing bipolar disorder. Ongoing medication management within a treatment relationship that revisits and adjusts the approach over time helps keep treatment on track as your needs change. The full picture of bipolar disorder treatment is more comprehensive than any single medication or even any single modality.

Are Mood Stabilizers Ever Used Outside Bipolar Disorder?

Yes. Using a medication for a purpose the FDA hasn’t approved is called off-label use. It’s legal, and the FDA says providers may prescribe a drug this way when they judge it medically appropriate. It’s also common in psychiatry and across medicine: one national study found that nearly half of anticonvulsant prescriptions were off-label, and that most off-label use overall had little or no scientific support. So the useful question isn’t whether a use is off-label, but how good the evidence for it is.

Lithium for depression that hasn’t improved enough. Adding lithium to an antidepressant is one of the better-studied options when depression hasn’t responded well. A review of trials found that people were more likely to respond when lithium was added than when a placebo was. This use is well supported, though most of the trials were small.

Lithium and suicide risk. Earlier reviews of trials found that lithium lowered the risk of suicide in people with mood disorders. But a large Veterans Affairs trial in veterans with depression or bipolar disorder who had recently survived a suicide-related event found that adding lithium to their usual care did not prevent repeat suicide-related events; the trial was stopped early for that reason. So lithium’s protective effect is debated, and simply adding lithium isn’t a reliable way to prevent suicide-related events.

Irritability or mood swings that don’t meet the criteria for bipolar disorder. Mood stabilizers and related medications are sometimes tried for these too. Here the evidence varies and is often limited. For example, a 2022 review of medications for borderline personality disorder, a condition with intense mood swings, found mostly very low-certainty evidence and concluded that no medication seems to treat the condition itself.

Lamotrigine for mood reactivity. Some prescribers use lamotrigine off-label for mood reactivity, irritability or emotional ups and downs, often in people with trauma, depression or anxiety. Small early studies, both in borderline personality disorder, were encouraging: in one, anger improved more with lamotrigine than with placebo, and in another, mood swings and impulsivity improved more. But the largest trial, also in borderline personality disorder, didn’t find a benefit over placebo, though only about a third of the people given lamotrigine were still taking it at the end of the year. So the evidence is mixed. In practice, some people find it helps them pause before reacting; that’s clinical experience, not proof. If your provider suggests it, it’s a careful, individual trial: you’ll watch together for real change, and stop if it isn’t helping. Its main serious risk is a rare but dangerous skin rash, which is why it’s started slowly.

Frequently Asked Questions

How long do I need to take a mood stabilizer?

For most people with bipolar disorder, mood stabilizers are a long-term or indefinite treatment. Stopping a mood stabilizer raises the chance that mood episodes come back. The decision about duration should be made carefully and collaboratively with your provider, weighing the risks of continuing against the risks of stopping. Please don’t stop a medication on your own; some can cause withdrawal symptoms or a return of symptoms if stopped suddenly.

What are the side effects of lithium?

Common side effects of lithium include fine hand tremor, increased thirst and urination, mild memory difficulties, and weight changes. Many side effects can be managed with your provider’s help. Lithium toxicity — which produces more serious symptoms — can happen at blood levels not far above helpful ones, so it requires awareness of risk factors including dehydration, certain medications, and kidney function changes. Regular blood monitoring is essential.

Is lamotrigine a mood stabilizer or an antidepressant?

Lamotrigine is a mood stabilizer that was originally developed as an anticonvulsant. It is not an antidepressant, and exactly how it works in bipolar disorder hasn’t been established. Its mood-stabilizing effects in bipolar disorder appear to be particularly beneficial for preventing depressive episodes, which is why it’s often chosen when depression is the main problem.

Can I take mood stabilizers during pregnancy?

This is a complex clinical question that depends on the specific medication. Valproate can cause serious birth defects and lower IQ in children exposed before birth, so it should not be used in pregnancy unless other medications have not worked or are not suitable. Lithium carries risks that require careful management and monitoring during pregnancy. Pregnancy registries have not found a higher rate of major birth defects with lamotrigine than in the general population, though monitoring is still important. Any pregnancy planning with bipolar disorder should involve a proactive clinical conversation about medication management.

If you are navigating medication decisions for bipolar disorder — whether starting treatment, reconsidering your current regimen, or planning a pregnancy — those decisions deserve individualized clinical attention rather than general information alone.