Ketamine Therapy for Bipolar Depression

Ketamine for bipolar depression is off-label, third-line, mood-stabilizer-required medicine. The evidence is real but much smaller than for unipolar treatment-resistant depression: two NIMH RCTs from the Zarate group (Diazgranados 2010, Zarate 2012), a handful of meta-analyses, and a 2018 Wilkinson levels-of-evidence review. Spravato (esketamine) is not approved for bipolar depression in Canada or the United States; only racemic ketamine has been studied in this population. CANMAT/ISBD's bipolar guidelines (Yatham et al. 2018, with subsequent updates) place ketamine outside primary recommendations and treat it as third-line or research-stage. Two clinical realities matter most: (1) patients must be on a therapeutic mood stabilizer before ketamine is considered, and (2) baseline screening for hypomanic or manic features is non-negotiable. This article walks through the evidence honestly and explains how ATMA CENA screens bipolar patients.

Key takeaways

• Ketamine for bipolar depression is off-label and third-line in current Canadian guidelines (Canadian Network for Mood and Anxiety Treatments / International Society for Bipolar Disorders, CANMAT/ISBD 2018; subsequent updates have not changed positioning materially).
• Spravato is approved for unipolar treatment-resistant depression only. It is not approved for bipolar depression. Only racemic ketamine has RCT data in bipolar populations.
• The two foundational RCTs — Diazgranados et al. 2010 (Arch Gen Psychiatry) and Zarate et al. 2012 (Biol Psychiatry) — were small (N=18, N=15) but consistently positive, with rapid antidepressant effects in patients on therapeutic lithium or valproate.
• Patients must be stable on a therapeutic mood stabilizer (lithium, valproate, lamotrigine, atypical antipsychotic) before ketamine is considered. ATMA CENA requires confirmation of mood stabilizer at therapeutic level at intake.
• Manic-switch risk in published trials has been low (~1.7% across 235 patients in pooled studies), but baseline screening for current or recent hypomanic/manic features is a hard exclusion.
• The evidence base is much smaller than unipolar treatment-resistant depression (TRD) — patients deserve to know the asymmetry honestly.

What is ketamine-assisted therapy for bipolar depression?

Ketamine therapy uses sub-anaesthetic doses of ketamine — a Health Canada-approved anaesthetic — paired with structured psychotherapy. Health Canada has approved ketamine as an anaesthetic; psychiatric use is off-label, a legal and common practice in Canadian medicine. Spravato (intranasal esketamine) is Health Canada-approved for treatment-resistant MDD as of May 2020, with no bipolar indication. All ketamine-for-bipolar in Canada uses racemic ketamine off-label, in patients on a mood stabilizer.

For the full mechanism breakdown, see What Is Ketamine Therapy?.

If you want to explore whether you may be eligible, book an information call with ATMA CENA to discuss your diagnosis, current mood stabilizer, and treatment history.

How ketamine could help bipolar depression — and why mood stabilizers matter

Ketamine acts on the brain's glutamate system through N-methyl-D-aspartate (NMDA) receptor antagonism, alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor activation, brain-derived neurotrophic factor (BDNF) release, and synaptogenesis (Aleksandrova et al., 2017). The mechanistic rationale in bipolar depression is similar to unipolar TRD — the depressive episode shares glutamatergic and synaptic-density abnormalities — but the clinical context is different. Bipolar patients carry baseline vulnerability to mood elevation; any antidepressant intervention raises the question of switch risk.

This is why mood stabilizers matter: a therapeutic-level mood stabilizer (lithium, valproate, lamotrigine, or an atypical antipsychotic with mood-stabilizing efficacy such as quetiapine, lurasidone, or cariprazine) provides a guardrail against mood elevation. The published bipolar-depression ketamine RCTs were specifically designed in patients on therapeutic lithium or valproate, not as monotherapy.

What the bipolar-specific evidence actually shows

Diazgranados 2010 — the first bipolar-depression RCT

Diazgranados et al. 2010 — Archives of General Psychiatry — randomized 18 patients with treatment-resistant bipolar I or II depression to single-dose IV ketamine 0.5 mg/kg or saline placebo, in a within-subject crossover design. Patients were on therapeutic lithium or valproate. Ketamine produced significant antidepressant effects (MADRS) within 40 minutes, peaking at 2 days; 71% of patients met response criteria within 24 hours of ketamine versus 6% with placebo. Effects waned over 2 weeks (PubMed).

Zarate 2012 — replication

Zarate et al. 2012 — Biological Psychiatry — replicated the protocol in 15 patients with treatment-resistant bipolar depression on lithium or valproate, again with single-dose 0.5 mg/kg IV ketamine versus saline crossover. Antidepressant effects were rapid and robust; the replication strengthened confidence in the original finding (PubMed).

Pooled and synthesis evidence

Bartoli et al. 2017 — Psychiatry Research — meta-analyzed the available bipolar-depression ketamine trials. Pooled response rates favoured ketamine over placebo, with rapid onset consistent with the unipolar pattern. The authors flagged the small sample size and call for larger trials.

Wilkinson et al. 2018 — Bipolar Disorders — reviewed levels of evidence for ketamine in bipolar depression, concluding that the evidence supports rapid antidepressant efficacy in carefully selected patients on mood stabilizers but remains limited in scale.

Yale group reports (2023–2024) — observational data from real-world bipolar patients receiving ketamine or esketamine alongside mood stabilizers describe similar rapid response patterns and acceptable safety in carefully screened populations.

Manic-switch risk in published data

Across the published RCTs and observational studies, manic-switch incidence has been low — pooled estimates around 1.7% across approximately 235 participants (lower than the 3–10% rates historically reported for traditional antidepressants in bipolar populations). Importantly, the published trials enrolled patients on therapeutic mood stabilizers and excluded those with recent hypomanic or manic episodes. Real-world risk for patients without those guardrails has not been characterized in trials.

The honest summary: ketamine produces rapid antidepressant effects in selected bipolar-depression patients on mood stabilizers; effect durability is similar to unipolar TRD (days to weeks per dose); and the evidence base is much smaller — single RCTs with N=15–18 plus observational data — than the hundreds of patients in unipolar ketamine and Spravato trials.

Where Canadian guidelines place ketamine in bipolar care

CANMAT/ISBD's 2018 bipolar disorder management guidelines (Yatham et al., Bipolar Disorders) place quetiapine, lurasidone, lithium + lamotrigine, lithium or lamotrigine monotherapy, and olanzapine-fluoxetine combination as first-line treatments for bipolar I depression, with cariprazine as a more recent addition. Ketamine is positioned as a third-line or research-stage option, reflecting the small evidence base. Subsequent CANMAT/ISBD updates have not materially changed this positioning.

CANMAT's 2021 racemic ketamine task force (Swainson et al., Canadian Journal of Psychiatry) noted that ketamine evidence in bipolar depression is "preliminary and needs to be replicated in larger controlled studies." The practical takeaway: Canadian clinical guidelines treat ketamine for bipolar depression as third-line, mood-stabilizer-conditional, and informed-consent-heavy.

How ATMA CENA screens bipolar patients

The ATMA CENA intake call works through several screening points specific to bipolar depression:

1. Diagnostic confirmation. Bipolar I, bipolar II, or other specified bipolar; cyclothymia is screened separately. For patients without a confirmed bipolar diagnosis, mood-history screening at intake may surface bipolarity that changes the treatment plan.
2. Mood stabilizer status. ATMA CENA requires confirmation of a therapeutic-level mood stabilizer (lithium, valproate, lamotrigine, or a mood-stabilizing atypical antipsychotic) before ketamine is considered. Recent labs (lithium level, valproate level, where applicable) are reviewed.
3. Recent mood elevation. Hypomanic or manic episode within the past 3 months (or active mixed features) is typically a hard exclusion. ATMA CENA's clinical team coordinates with the prescribing psychiatrist on timing.
4. Comedication review. Concurrent antidepressants are reviewed; benzodiazepines may blunt ketamine's effect.
5. Coordinated psychiatric care. Bipolar patients require ongoing psychiatric oversight beyond ATMA CENA's KAP infrastructure. ATMA CENA's coordinated care model explicitly accommodates this — your treating psychiatrist remains primary, while ATMA CENA's network provides medical oversight specific to ketamine dosing.

Who is a candidate?

Inclusion criteria for bipolar-depression ketamine referrals typically require:

• Adults 18 or older
• DSM-5 diagnosis of bipolar I depression, bipolar II depression, or other specified bipolar with documented depressive episode
• Currently stable on a therapeutic mood stabilizer (lithium, valproate, lamotrigine, or mood-stabilizing atypical antipsychotic)
• Documented adequate trials of first-line bipolar-depression treatments (quetiapine, lurasidone, lithium + lamotrigine, olanzapine-fluoxetine combination, or cariprazine, depending on bipolar I vs II)
• Medically stable; able to provide informed consent
• No hypomanic, manic, or mixed episode in the past 3 months
• Realistic expectations grounded in the small evidence base

Absolute contraindications: active mania or hypomania (recent or current), active psychosis, uncontrolled severe hypertension, severe cardiovascular disease, current pregnancy, anaphylactic reaction to ketamine.

For full eligibility detail, see How to Qualify for Ketamine Therapy in Canada.

Cost and insurance

ATMA CENA's published KAT pricing applies: KAT Psychedelic Pathway from CAD $1,585 + $795 per additional session; KAT Psycholytic Pathway from CAD $1,530 + $740 per additional session; customized programs CAD $2,325–$6,930. A non-refundable deposit of CAD $300 applies. For full pricing context, see Ketamine Therapy Cost in Canada.

Insurance reality for bipolar: Spravato is the form most likely to be covered by private insurance with prior authorization — but Spravato is not approved for bipolar depression, so the typical Spravato coverage pathway does not apply to bipolar patients. Generic IV/IM/sublingual ketamine for psychiatric use is generally not covered by private insurance, and provincial drug plans do not cover off-label ketamine for psychiatric indications. Most bipolar patients pay out-of-pocket. For full insurance navigation, see Insurance Coverage for Ketamine Therapy.

Frequently asked questions

Is ketamine approved for bipolar depression in Canada? No. Ketamine is approved by Health Canada as an anaesthetic; psychiatric use is off-label. Spravato (esketamine) is approved only for unipolar treatment-resistant depression — not for bipolar depression. All ketamine-for-bipolar in Canada uses racemic ketamine off-label.

Can I do Spravato for bipolar depression? No. Spravato's Health Canada and FDA indications are explicitly unipolar major depressive disorder (treatment-resistant or with acute suicidal ideation). Bipolar depression is not on label. Off-label Spravato use in bipolar patients is rare and would be at the prescribing physician's discretion outside the approved indication.

Do I have to be on a mood stabilizer? Yes. The published bipolar-depression ketamine RCTs were specifically conducted in patients on therapeutic lithium or valproate. ATMA CENA requires confirmation of a therapeutic-level mood stabilizer before ketamine is considered. Lamotrigine, quetiapine, lurasidone, cariprazine, and other mood-stabilizing options are also accepted.

What's the manic-switch risk? In published trials with appropriate screening (mood stabilizer at therapeutic level; no recent hypomania/mania), pooled manic-switch incidence has been ~1.7% across about 235 patients — lower than rates historically reported for traditional antidepressants in bipolar populations. Baseline screening matters; real-world risk in patients without those guardrails is not characterized.

How small is the evidence base, honestly? Two foundational RCTs: Diazgranados 2010 (N=18) and Zarate 2012 (N=15) — both single-dose, in patients on lithium or valproate. A handful of meta-analyses pool these and a few open-label series. By comparison, unipolar TRD has hundreds of patients across multiple RCTs and dozens of replication studies, plus the Spravato pivotal trials. Patients deserve to know this asymmetry.

How does ketamine work alongside lithium or valproate? Lithium and valproate do not appear to have significant pharmacokinetic interactions with ketamine in the published literature; the bipolar-depression RCTs were conducted with patients on therapeutic levels of these mood stabilizers. Lamotrigine has limited data and some signals of attenuated ketamine effect — discuss with your prescriber.

Can I combine ketamine with my existing psychiatric treatment? Yes — through the coordinated care model. Bipolar depression requires ongoing psychiatric oversight; ATMA CENA's network does not replace your treating psychiatrist. The coordinated care model lets your psychiatrist remain primary while ATMA CENA provides medical oversight specific to ketamine dosing.

Is ketamine helpful for rapid-cycling bipolar? The published evidence base did not stratify rapid-cycling versus non-rapid-cycling subtypes, and rapid cycling itself is a marker of higher mood-instability risk. Patients with documented rapid cycling are typically evaluated cautiously case-by-case with the treating psychiatrist.

What about bipolar II? The Diazgranados 2010 and Zarate 2012 trials enrolled both bipolar I and bipolar II depression and found similar response patterns. Bipolar II patients are generally considered eligible under the same screening framework.

What if I don't have a confirmed bipolar diagnosis but worry I might be bipolar? ATMA CENA's intake call includes mood-history screening. Some patients referred with treatment-resistant unipolar depression actually have undiagnosed bipolar II, and surfacing this at intake changes the treatment plan in important ways. The honest screen is part of the value of the call.

Where can I get ketamine therapy for bipolar depression in Canada? See the city- and province-specific articles in this cluster: Calgary, Edmonton, Winnipeg, Toronto/GTA, Montreal, Ottawa, Mississauga, Hamilton, London ON, Halifax, Vancouver, Victoria BC, Kelowna, Saskatoon.

Sources

1. ATMA CENA — coordinated care: https://psychedelic.healthcare/find-care/
2. Diazgranados N, et al. (2010). Randomized add-on trial of an N-methyl-D-aspartate antagonist in treatment-resistant bipolar depression. Arch Gen Psychiatry. https://pubmed.ncbi.nlm.nih.gov/20679587/
3. Zarate CA Jr, et al. (2012). Replication of ketamine's antidepressant efficacy in bipolar depression. Biol Psychiatry. https://pubmed.ncbi.nlm.nih.gov/22297150/
4. Bartoli F, et al. (2017). Ketamine as a rapid-acting antidepressant in bipolar depression: meta-analysis. Psychiatry Res. https://pubmed.ncbi.nlm.nih.gov/28599155/
5. Wilkinson ST, et al. (2018). Levels of evidence for the use of ketamine in bipolar depression. Bipolar Disord. https://pubmed.ncbi.nlm.nih.gov/29947058/
6. Yatham LN, et al. (2018). CANMAT and ISBD 2018 guidelines for the management of patients with bipolar disorder. Bipolar Disord. https://www.canmat.org/wp-content/uploads/2019/07/Yatham-LN-2018-CANMAT-ISBD-guidelines-for-bipolar-disorder-Bipol-Disord.pdf
7. Swainson J, et al. (2021). CANMAT racemic ketamine task force recommendations. Can J Psychiatry. https://pubmed.ncbi.nlm.nih.gov/33174760/
8. Aleksandrova LR, et al. (2017). Antidepressant mechanisms of ketamine. Can J Psychiatry. https://pubmed.ncbi.nlm.nih.gov/28234212/
9. Health Canada DPD — Spravato (esketamine): https://health-products.canada.ca/dpd-bdpp/info?lang=eng&code=98903
10. Yale Medicine — Bipolar disorder patients respond to ketamine, esketamine treatment: https://medicine.yale.edu/news-article/yale-study-bipolar-disorder-patients-respond-to-ketamine-esketamine-treatment/

Related articles in this cluster

• Ketamine Therapy in Canada
• What Is Ketamine Therapy?
• Ketamine Therapy for Depression
• Ketamine Therapy for Treatment-Resistant Depression (deep dive)
• Ketamine Therapy for Anxiety
• Ketamine Therapy for PTSD
• Insurance Coverage for Ketamine Therapy
• How to Qualify for Ketamine Therapy in Canada
• Find care near you

Last updated: 2026-05-06