Ketamine for Bipolar Depression: Is It Safe? (2026)

Ketamine can work for bipolar depression, and it can work fast. In the two best-known controlled trials, most patients with treatment-resistant bipolar depression responded to a single dose, often within an hour. Those patients were also all taking lithium or valproate, and that detail decides who can safely get ketamine. If you have bipolar disorder and are considering ketamine, the question is not really "does it work?" It is "is my mood stable enough, and am I protected enough, that a fast antidepressant won't push me the other way?"

I prescribe at-home ketamine and see bipolar patients regularly. This post covers what the evidence shows, how real the mania risk is, why a mood stabilizer matters so much, and how I decide who is a good candidate. For the overview of our program for this condition, see ketamine for bipolar depression.

Why bipolar depression is so hard to treat

Bipolar depression is the part of bipolar disorder that tends to do the most damage. For most people with bipolar I or II, depressive episodes last longer and come more often than manic or hypomanic ones. Yet the options are narrower than for ordinary depression.

Standard antidepressants are the core problem. In unipolar depression, an SSRI is a reasonable first step. In bipolar disorder, antidepressants on their own often don't work well for the depression and can trigger a switch into hypomania or mania, or speed up cycling. So most bipolar patients are treated with mood stabilizers and certain antipsychotics. Those take weeks to work, have meaningful side effects, and leave many people still depressed.

That is the gap ketamine might fill: something that works in hours or days rather than weeks, through a completely different mechanism (the glutamate system rather than serotonin).

What the research actually shows

The evidence for ketamine in bipolar depression is real but small. Here is what it consists of.

The NIMH trials. The landmark study was a randomized, placebo-controlled crossover trial at the National Institute of Mental Health (Diazgranados et al., 2010). Eighteen patients with treatment-resistant bipolar depression, all maintained on lithium or valproate, received a single IV dose of ketamine and, on a separate day, placebo. Depression improved significantly within 40 minutes and stayed better for about three days. Seventy-one percent responded to ketamine at some point, compared with 6% on placebo.

The same group then repeated the study with a new set of 15 patients, again on lithium or valproate (Zarate et al., 2012). The result held: 79% responded to ketamine and none to placebo, and suicidal thinking also dropped quickly.

Suicidal thoughts. A Columbia University pilot trial compared ketamine with midazolam, an active control, in 16 bipolar patients with suicidal ideation (Grunebaum et al., 2017). Suicidal thoughts fell more after ketamine, but the difference did not reach statistical significance in a sample that small. It is encouraging, not proof.

The bigger picture. A 2023 Mayo Clinic systematic review and meta-analysis pooled the available ketamine and esketamine studies in bipolar depression (Nunez et al., 2023). In the non-randomized studies, about 53% of patients responded and 38% reached remission. Single and repeated dosing produced similar response rates. The authors were clear that the total number of patients studied is small and larger trials are needed.

Two honest caveats:

Almost all of this is IV ketamine in a research unit. At-home sublingual ketamine has not been tested specifically in bipolar patients in a controlled trial. The pharmacology is the same drug, but the delivery and monitoring are different.
Spravato (esketamine) is not approved for bipolar depression. Its approval trials enrolled patients with major depressive disorder, not bipolar disorder.

So ketamine for bipolar depression is off-label and supported by small studies with consistent results. It is a reasonable option for the right patient, not a first-line treatment for everyone with bipolar disorder.

How real is the mania risk?

This is the question I get most, and it is the right one to ask. Any treatment that lifts mood quickly could, in theory, overshoot into hypomania or mania.

In the studies, this has been uncommon. In the original NIMH trial, one patient on ketamine and one on placebo developed manic symptoms, which suggests the illness itself, not the drug, accounted for at least some of it. Across the studies in the 2023 meta-analysis, the switch rate was about 2.4%.

But that low number comes with conditions. The patients in those studies:

were taking a mood stabilizer at therapeutic levels
were in a depressive episode, not a mixed or elevated state
were screened carefully and watched closely after each dose

People who were manic, mixed, or not on any mood stabilizer were left out of these trials. So the honest statement is: with a mood stabilizer on board and good screening, the switch risk appears low. Without those protections, we simply don't have data, and the theoretical risk is higher.

Why the mood stabilizer matters

In the trials, the mood stabilizer is what kept the risk low, so I treat it as essential, not optional. If ketamine gives your mood a fast lift, the mood stabilizer is what keeps that lift from turning into a manic episode.

A few points about specific medications:

Lithium and valproate. These were the mood stabilizers used in the NIMH trials. An analysis of 36 of those patients found that ketamine worked on either one, and neither drug's blood level predicted how well ketamine worked (Xu et al., 2015). So you don't need to switch mood stabilizers to try ketamine.
Lamotrigine. Many bipolar II patients are on lamotrigine. In a study of healthy volunteers, taking lamotrigine before ketamine reduced ketamine's dissociative and perceptual effects, while slightly increasing its immediate mood lift (Anand et al., 2000). That was a single high dose in people without depression, so it doesn't tell us much about antidepressant response. In practice, it means a patient on lamotrigine may experience sessions as milder, and I take that into account when adjusting dose.
Antipsychotics used for bipolar (quetiapine, lurasidone, aripiprazole, and others). These count as mood-stabilizing coverage. I review them for sedation and blood pressure effects alongside ketamine, the same way I review every medication. More on that in medication safety with ketamine.

If you are also taking an antidepressant prescribed by your psychiatrist alongside your mood stabilizer, that is usually fine with ketamine. See combining ketamine with antidepressants.

Who is a good candidate, and who isn't

Here is how this works in our program. Our intake asks directly about bipolar disorder and whether you are on a mood stabilizer.

Usually a good fit:

Bipolar II, or bipolar I, currently in a depressive episode
Taking a mood stabilizer (lithium, valproate, lamotrigine, or an antipsychotic used for bipolar) consistently
Mood has been stable, with no hypomanic or manic symptoms in roughly the past three months
Under the care of a psychiatrist who knows about and agrees with trying ketamine

Needs my personal review first:

Bipolar disorder without a current mood stabilizer, or unsure what counts as one
Rapid cycling, or a history of switching into mania on antidepressants
Recent medication changes to the mood stabilizer

Not a fit for at-home ketamine:

Currently manic, hypomanic, or in a mixed episode
Untreated bipolar I
Psychotic symptoms

These sit alongside the general screening that applies to everyone, such as blood pressure, heart and liver health, and substance use history. The full list is in our guide to ketamine contraindications.

What treatment looks like with bipolar disorder

The structure is the same as for anyone else in our program: a physician evaluation, then sublingual sessions at home with a sober adult nearby, usually 10 or more sessions over 4 to 8 weeks, then a maintenance plan if it's working. A few things are different for bipolar patients:

Your psychiatrist stays involved. I am not replacing the person managing your mood stabilizer. I want them to know you're starting ketamine and to keep managing that medication.
We track mood in both directions. Every patient fills out regular depression ratings. For bipolar patients I'm also watching for signs of mood going too high, not just whether depression is improving.
Starting doses are conservative. I would rather go up gradually than find out the hard way that someone is sensitive.

You and the people you live with should know the early signs of hypomania. These include sleeping much less without feeling tired, racing thoughts, talking faster, unusual irritability, impulsive spending or decisions, and feeling unusually invincible. If those appear, pause sessions and contact both me and your psychiatrist the same day. A few days off ketamine is a small price for catching it early.

It also helps to know the difference between feeling better and going high. After a long depression, having energy again and making plans can feel strange. That's recovery, not mania. What I watch for is a change in sleep, speed, and judgment, not simply feeling good. I wrote more about what sustained improvement tends to feel like in ketamine and mood stability.

The bottom line

For bipolar depression, ketamine is one of the few treatments that works in hours rather than weeks, and the controlled trials, though small, have consistently shown strong response rates with a low switch rate. Those results came from patients who were on a mood stabilizer, in a stable depressive episode, and carefully screened. Those protections are what made the low switch rate possible, not optional extras.

If you're on a mood stabilizer, your mood has been stable apart from the depression, and your psychiatrist is on board, ketamine is a reasonable option to discuss. If you're not sure where you fall, complete the eligibility screening and I will review your history personally.

Frequently Asked Questions

Can people with bipolar disorder take ketamine?

Many can, specifically for the depressive phase. The controlled trials of ketamine in bipolar depression showed strong, fast responses in patients who were on lithium or valproate. People who are currently manic, hypomanic, or mixed, or who have untreated bipolar I, are not good candidates for at-home ketamine.

Can ketamine trigger mania?

It can, but in the studies it has been uncommon. The switch rate across studies in a 2023 meta-analysis was about 2.4%, and in the original NIMH trial one patient on ketamine and one on placebo developed manic symptoms. Those patients were all on mood stabilizers and carefully screened, which is why I require the same protections.

Do I need to be on a mood stabilizer to get ketamine for bipolar depression?

In our program, a mood stabilizer is the expected baseline, because that is how ketamine was studied and it is what keeps the mania risk low. If you have bipolar disorder and aren't on one, you are not automatically ruled out, but I review your history personally before anything is prescribed.

Does ketamine work for bipolar II as well as bipolar I?

The trials included both, and response rates were similar. In practice, stable bipolar II on a mood stabilizer is the most straightforward case. Bipolar I can also be treated when it is well controlled, but I am more cautious with it.

Does lamotrigine stop ketamine from working?

There's no good evidence that it does. In healthy volunteers, lamotrigine reduced ketamine's dissociative effects and slightly increased its immediate mood effect. Sessions may feel milder on lamotrigine, and I adjust the dose with that in mind, but it isn't a reason to stop either medication.

Is Spravato approved for bipolar depression?

No. Spravato (esketamine) is FDA-approved for treatment-resistant major depression and depression with suicidal thoughts, and its approval trials did not include bipolar patients. Any ketamine or esketamine use in bipolar depression is off-label.

How fast does ketamine work for bipolar depression?

In the NIMH trials, depressive symptoms improved within 40 minutes of a single IV dose and stayed better for about three days. With at-home sublingual treatment, most people need a course of sessions, typically 10 or more over 4 to 8 weeks, to get a lasting effect.

Should my psychiatrist be involved?

Yes. I want your psychiatrist to keep managing your mood stabilizer and to know you're starting ketamine. For bipolar patients, I ask for that confirmation as part of the evaluation.

References

Diazgranados N, Ibrahim L, Brutsche NE, Newberg A, Kronstein P, Khalife S, et al. A randomized add-on trial of an N-methyl-D-aspartate antagonist in treatment-resistant bipolar depression. Arch Gen Psychiatry. 2010;67(8):793-802. PubMed: 20679587 18 patients on lithium or valproate; 71% responded to a single ketamine infusion vs 6% on placebo, with improvement within 40 minutes.
Zarate CA Jr, Brutsche NE, Ibrahim L, Franco-Chaves J, Diazgranados N, Cravchik A, et al. Replication of ketamine's antidepressant efficacy in bipolar depression: a randomized controlled add-on trial. Biol Psychiatry. 2012;71(11):939-946. PubMed: 22297150 Independent replication in 15 patients: 79% responded to ketamine and 0% to placebo; suicidal ideation also improved rapidly.
Grunebaum MF, Ellis SP, Keilp JG, Moitra VK, Cooper TB, Marver JE, et al. Ketamine versus midazolam in bipolar depression with suicidal thoughts: A pilot midazolam-controlled randomized clinical trial. Bipolar Disord. 2017;19(3):176-183. PubMed: 28452409 Pilot of 16 patients; suicidal ideation fell more after ketamine than midazolam at a trend level (P=.074), with replication needed.
Nunez NA, Joseph B, Kumar R, Douka I, Miola A, Prokop LJ, et al. An Update on the Efficacy of Single and Serial Intravenous Ketamine Infusions and Esketamine for Bipolar Depression: A Systematic Review and Meta-Analysis. Brain Sci. 2023;13(12):1672. PubMed: 38137120 Pooled response 53% and remission 38% in non-randomized studies; affective switch rate approximately 2.4%.
Xu AJ, Niciu MJ, Lundin NB, Luckenbaugh DA, Ionescu DF, Richards EM, et al. Lithium and Valproate Levels Do Not Correlate with Ketamine's Antidepressant Efficacy in Treatment-Resistant Bipolar Depression. Neural Plast. 2015;2015:858251. PubMed: 26137324 36 patients; ketamine improved depression on both lithium and valproate, and serum levels did not predict response.
Anand A, Charney DS, Oren DA, Berman RM, Hu XS, Cappiello A, et al. Attenuation of the neuropsychiatric effects of ketamine with lamotrigine. Arch Gen Psychiatry. 2000;57(3):270-276. PubMed: 10711913 Healthy-volunteer study: lamotrigine pretreatment reduced ketamine's dissociative effects and increased its immediate mood-elevating effect.

Dr. Ben Soffer is a board-certified physician who prescribes at-home ketamine therapy via telehealth in Florida, New Jersey, and California. This article is for general educational purposes and is not individualized medical advice. Ketamine is a prescription medication that should be used only under the supervision of a licensed clinician. If you are in crisis, call or text 988.

Ketamine for Bipolar Disorder: Mania Risk and Who Qualifies