What Disqualifies You From Ketamine Therapy? Dr. Explains.

You may have found your way here because talk therapy, selective-serotonin reuptake inhibitors, or months of mindfulness apps have chipped away at your depression or anxiety – but never fully cracked it. If that sounds familiar, you are not alone. According to an online survey of over a thousand people who inquired about ketamine treatment, more than 93 percent reported ongoing depression, almost two-thirds lived with chronic symptoms, and over 86 percent had already cycled through at least two antidepressants in the previous decade. Those numbers mirror what I see every week in our clinics from Toronto to Vancouver: smart, hard-working adults who have done everything “right” yet still wake up under a grey emotional sky.

I think that ketamine-assisted psychotherapy (often shortened to KAP) can be a remarkable lifeline when conventional treatments prove inadequate. In fact, I strongly believe that the combination of a fast-acting medicine with a structured course of psychotherapy is one of the most hopeful developments in modern mental-health care. At the same time, I can tell you that ketamine is not a universal remedy. My first responsibility as a physician is to keep you safe, and that means being crystal-clear about who should not receive this therapy – or who should wait until certain medical or psychosocial pieces are firmly in place.

Before we get into the ketamine therapy specifics, let me share two quick perspectives to anchor our discussion. First, my outlook is deeply shaped by research as well as bedside practice. A recent systematic review that examined ketamine combined with psychotherapy calls the approach “promising” while cautioning that more rigorous studies are needed. I agree; promise and prudence can – and must – coexist. Second, real-world data continue to expand the therapeutic envelope. A meta-analysis of randomized trials found that maintenance protocols can prolong ketamine’s anxiolytic effects, especially in people whose anxiety has resisted other treatments. That analysis strengthens my conviction that safety screening must be as robust as the treatment itself.

So, let’s map out the terrain you need to understand: the medical red lights, the yellow lights that require extra caution, and the life-logistics that influence whether KAP will truly serve you.

Ketamine Therapy in a Nutshell

Whenever someone asks me what ketamine therapy actually feels like, I start by explaining the scientific scaffolding behind the experience. Ketamine, at the low doses we use, nudges the brain into a dissociative state that loosens overly rigid thought patterns. The medicine also sparks a surge of brain-derived neurotrophic factor (BDNF), a chemical fertilizer of sorts that helps neurons sprout new connections. During this relatively brief window of heightened neuroplasticity, you and your therapist collaborate to plant healthier beliefs and coping skills. That is why the psychotherapy component – what happens before and after each dose – is just as important as the medicine itself.

In my experience, a typical course at Field Trip spans six sessions spread over three to six weeks, each one woven into a cycle of preparation and integration work.

Preparation sessions teach you practical tools – breath regulation, intention setting, and mindfulness drills – that keep you anchored when the medicine dissolves the usual boundaries of consciousness.

Integration sessions help you unpack the experience, assign meaning to the imagery, and translate insights into concrete lifestyle changes.

If you wonder about real-world results, let me share the words of Jordan, a film and stage actor who came to us after years of emotional numbness: “After two sessions I realized, ‘Wow. I’m actually enjoying stuff again.’” – Jordan.

Jordan’s story shows that quick relief is possible, but only after we make sure ketamine is right for you.

Absolute Ketamine Therapy Contraindications

Safety is our first priority. There are specific conditions that immediately and unequivocally preclude the use of ketamine, regardless of how compelling the need or desire for relief. These absolute contraindications reflect both the current scientific evidence and our ethical duty as clinicians.

1. Pregnancy or Breastfeeding.

In light of the limited controlled data in humans, ketamine is almost never recommended during pregnancy. If you are pregnant or nursing, ketamine is off the table for now.  The drug crosses the placenta and appears in breast milk, and data on fetal or neonatal safety remain extremely thin.

I know that waiting can feel frustrating when you are suffering, but postponing treatment protects two lives, not just one. During that interlude we can explore non-pharmacologic strategies, coordinate rTMS, or adjust existing medications under the guidance of your obstetric team.

2. Serious Cardiovascular Instability.

Ketamine reliably raises heart rate and blood pressure. If you walk into my office with untreated hypertension hovering above 160/100, recent myocardial infarction, or unstable angina, ketamine is simply unsafe. Instead, we route you to your cardiologist, optimize your cardiovascular status, and revisit the discussion only when your baseline vitals are within acceptable limits.

3. Active Psychosis or Untreated Mania.

Because ketamine can intensify perceptual distortions, anyone grappling with hallucinations, delusions, or a manic episode is at high risk for worsening symptoms. In those scenarios our clinical priority shifts to stabilizing the underlying psychotic or mood disorder – usually with antipsychotic medication and structured psychotherapy – before we consider any psychedelic-adjacent intervention.

4. Elevated Intracranial or Intraocular Pressure.

Whether you are recovering from a traumatic brain injury or managing narrow-angle glaucoma, the small but measurable rise in intracranial pressure that accompanies ketamine could tip you into a medical emergency. Surgical or ophthalmologic clearance is mandatory, and often ketamine remains permanently contraindicated.

5. Severe Hepatic Impairment.

If lab tests show that your liver function has slipped into the Child-Pugh C range, your body cannot metabolize ketamine safely. Alcohol-related cirrhosis is the most common culprit I see. In such cases we focus on liver-protective measures and, when appropriate, refer you for rTMS or Dual Sympathetic Reset instead.

6. Inability to Provide Informed Consent.

Ketamine treatment hinges on your capacity to understand risks, benefits, and alternatives. Acute intoxication, severe cognitive impairment, or the absence of a legal guardian in cases of intellectual disability automatically halts the process until genuine informed consent is possible.

Relative Ketamine Therapy Contraindications

Not every obstacle is absolute. Some medical conditions, while not outright prohibiting ketamine therapy, demand a vigilant, calculated approach. In these gray zones, risk is not eliminated, only managed – requiring careful adjustment to protocols and a heightened level of clinical oversight to ensure safety at every stage.

1. Controlled Hypertension and Mild Heart Disease.

Let’s say your blood pressure sits around 140/90 on a stable medication regimen. You’re not disqualified, but we will spend extra time calibrating dose, schedule, and monitoring. A smaller initial ketamine infusion, continuous blood-pressure monitoring, and post-session observation extend your overall chair time, yet those safety layers are worth every minute.

2. Bipolar Disorder in the Depressive Phase.

Ketamine can be transformative for bipolar depression, but mood elevation can flip into mania if mood stabilizers are absent or sub-therapeutic. In my clinical pathway you must be on a stabilizer – lithium, lamotrigine, or valproate – before we proceed, and a trusted family member needs to monitor for early hypomanic cues at home.

3. Substance-Use Disorders in Early Recovery.

While ketamine shows early promise for alcohol and opioid use disorders – a recent scoping review highlights that potential – we need at least several weeks of sobriety to reduce the dual risks of relapse and respiratory depression.

4. Obstructive Sleep Apnea.

If you have moderate-to-severe sleep apnea, untreated airway obstruction can magnify ketamine’s sedative properties. Bringing your CPAP device to each session and sitting for extended recovery monitoring helps mitigate respiratory compromise.

5. High Anxiety About Dissociation.

Some prospective clients fear “losing control.” In my experience, three extended preparation sessions, combined with a gentle intramuscular micro-dose for the first medicine day, often diffuses that anxiety. When education and graduated exposure do not relieve the fear, we postpone ketamine treatment and pivot to conventional cognitive-behavioural therapy aimed at distress tolerance.

Psychosocial Factors That Can Make or Break Ketamine Therapy Success

Beyond the medical checklist, certain life circumstances and inner dynamics decisively influence whether ketamine-assisted psychotherapy delivers lasting benefits or falls short. I strongly believe these are not minor considerations: the emotional landscape you bring into the room, the clarity and realism of your expectations, the strength of your support system, and your practical ability to commit time and resources – each acts as a pillar (or obstacle) in your healing journey.

1. Motivation and Expectations.

You might arrive hoping ketamine will “knock out” depression the way a surgeon excises an inflamed appendix. I need you to know that KAP is a partnership, not a pill. In my practice, clients who view the medicine as a catalyst – one piece of a broader mental-health toolkit – consistently outperform those searching for a silver bullet.

2. Support Network.

During a dissociative experience, emotional defenses soften. If you lack at least one stable relationship – whether that’s a spouse, friend, or professional therapist – the flood of raw feeling can overwhelm you once the medicine wears off. Whenever I sense a support deficit, we hit pause and help you create that safety net first.

3. Financial and Time Logistics.

Across Canada, public insurance plans – such as OHIP in Ontario – rarely, if ever, cover ketamine therapy for mental health, meaning ketamine infusion treatments are typically paid for out of pocket.

I know that money talk feels awkward in a medical consult, but financial stress can sabotage treatment when it hovers like a storm cloud over every session.

We discuss openly whether our KAP program fits your budget and schedule. If not, we collaborate on alternatives, ensuring that treatment remains accessible. We may adjust the frequency of sessions, refer you to other practitioners, or help you navigate financial assistance programs where available.

Why I Sometimes Say “Not Yet” to Ketamine Therapy

Suicidal crisis is the most common pivot point. While ketamine has well-documented anti-suicidal effects, the psychological vulnerability during an acute crisis demands a higher-intensity monitoring environment than an outpatient clinic can provide. I send those clients to an inpatient unit, where psychiatric staff can observe around the clock; once stability emerges, we re-evaluate.

Another frequent pivot involves medication changes. People occasionally decide – without medical supervision – to stop their SSRI because they “want the full ketamine effect.” Abrupt withdrawal carries real danger, including serotonin discontinuation syndrome and rebound depression. At Field Trip clinics, we guide a carefully tapered plan before introducing ketamine, ensuring our clients never stand unprotected pharmacologically.

Finally, when someone’s living arrangements are precarious or life circumstances are tumultuous, I often advocate for a pause. Without the security of stable housing or a predictable environment, integration – the heart of ketamine therapy – can’t thrive. Meeting survival needs is the first priority.

Medication Interactions that Matter

Benzodiazepines, especially high daily doses of clonazepam or lorazepam, can mute ketamine’s antidepressant lift. Your doctor may negotiate a temporary dose reduction 24 hours before each session. Some clients accept that trade-off to avoid emotional overwhelm; others prefer a brief taper under psychiatric supervision.

MAO inhibitors are rare these days, but if you take one, we will consult a pharmacologist because the combination may spike blood pressure unpredictably.

Finally, opioids and alcohol can amplify sedation. A 48-hour abstinence window is mandatory.

The Most Common Ketamine Therapy Questions

No question is too small or too complex. I’ve compiled a list of the most common inquiries I and our doctors at Field Trip Health clinics receive.

Can I still qualify if my blood pressure is borderline?

Possibly. I will liaise with your family doctor or cardiologist to optimize your regimen. Once we achieve consistent readings below 140/90, ketamine may become feasible with extended monitoring.

I had a frightening ketamine experience at a party years ago. Does that disqualify me?

Not automatically. Recreational settings lack medical supervision, precise dosing, and psychological support. Structured preparation, carefully titrated dosing, and a therapist at your side create a very different landscape. We will review your prior experience in depth and start at a lower dose to foster a sense of safety.

Will stopping my antidepressant help ketamine work better?

The evidence does not support wholesale discontinuation. In fact, sudden cessation can provoke severe withdrawal and rebound depression. Any medication changes should unfold gradually under medical supervision, and in many cases we leave baseline medications intact while adding ketamine.

Is rTMS more likely to be covered by insurance?

rTMS coverage varies across Canadian provinces and insurance plans. Our administrative team can investigate your benefits and navigate prior authorization paperwork on your behalf.

Ketamine Therapy: Decision-Making

I used to sketch a tidy decision tree on the whiteboard during information sessions, but I’ve learned that real life refuses to stay within clean geometric lines. Instead, picture your candidacy as a story with several chapters.

• The first chapter explores biological safety – vitals, labs, comorbidities.
• The second zooms in on psychiatric stability – no recent mania, psychosis, or substance relapse.
• The third chapter examines social context and readiness. Do you have a support system sturdy enough to help you unpack profound insights?
• Chapter four deals with expectation management: are you hoping for a miracle or committing to a collaborative process?
• And finally, chapter five synthesizes the first four chapters in an interdisciplinary meeting where every clinician involved in your care signs the same page. Only then does the ketamine therapy enter the story.

Conclusion

If spending the last ten minutes with me has done anything, I hope it has clarified that good medicine thrives on both optimism and discernment. Ketamine therapy can be life-altering, as Jordan and many others will attest, yet responsible care starts with knowing when not to proceed. Whether the roadblocks involve pregnancy, cardiac risk, psychiatric instability, or life stresses that eclipse your bandwidth for deep inner work, acknowledging those constraints is an act of compassion, not deprivation.

View candidacy screening through the lens of self-respect and personal integrity. By rigorously vetting safety conditions, you honor your body and mind, protect your support network, and preserve the integrity of a therapy that holds genuine transformative power. Should you move forward, you will do so with confidence, clarity, and a team that treats your well-being as the north star of every clinical decision.

And if ketamine therapy turns out not to be your path, take heart in knowing that the mental-health landscape is rich with evidence-based alternatives – rTMS, Dual Sympathetic Reset, trauma-focused psychotherapy – each capable of tilting your life toward relief and possibility.

Thank you for investing your time and attention. If you have questions or wonder whether KAP or another advanced therapy suits your unique circumstances, reach out. My colleagues and I at Field Trip Health are here to listen, guide, and walk the next steps with you.

Yours in health and discovery, Dr. Mario Nucci.

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About the Author

Dr. Mario Nucci MD CCFP is a licensed Family Physician with a passion for mental health and the development of new therapies. He is actively engaged in research with a faculty associate professorship at Northern Ontario School of Medicine, and research collaborations with the University of Ottawa, University of Calgary, Lakehead University, Concordia University and Vancouver Island University.

Dr. Nucci is the founder of Bay and Algoma Health Centre in 2019, a walk-in and addiction medicine clinic. He founded the Canadian Centre for Psychedelic Healing in 2019, now operating as Field Trip Health, providing cutting edge mental health care in  Toronto,  Montreal,  Vancouver,  Ottawa, Hamilton, Kitchener-Waterloo, Thunder Bay, Sault Ste. Marie, and at-home (BC, ON, & QC).