You may have landed here because months – perhaps years – of standard antidepressants, talk therapy, yoga apps, and self‑help podcasts have barely moved the needle on your mood. If that’s true, you’re not alone. Roughly one‑third of people treated for depression will continue to meet criteria for a “treatment‑resistant” form of the illness. As more of you search for innovative answers, ketamine‑assisted psychotherapy (KAP) often turns up at the top of the list for its reputation for rapid relief. Yet enthusiasm can’t outpace safety. I think that one crucial, sometimes uncomfortable question remains under‑discussed: Who should actually say no to ketamine – at least for now?
I want to address that question because, in my experience treating thousands of clients across our Field Trip Health clinics, the fastest way to “yes” is often a well‑reasoned “not yet”. Contraindications exist for good reason, and they’re not hypothetical.
My goal here is to offer a nuanced, comprehensive look at why ketamine isn’t for everyone and how you can sort through your own medical, psychiatric, and lifestyle factors before deciding. I’ll draw from clinical experience, current research, and voices like Grant’s, who found life‑changing healing through KAP – because success stories matter, but only when viewed through the lens of rigorous screening.
“In 2010 I was blown up in Afghanistan… I have sought various treatments in the past for my PTSD, but none of them have helped me nearly as much as Ketamine‑Assisted Therapy. After six sessions my general anxiety and depression have subsided, and I’m much happier.” – Grant, Former Military and recent University Graduate.
Grant’s success story holds undeniable power, but it is grounded in careful, individualized screening. I want to highlight the situations where ketamine treatment may need to be delayed or deemed unsuitable for some individuals – and, just as importantly, outline the key factors that make someone a good candidate.
Why We Even Need to Ask “Who Isn’t a Candidate?”
Spend just five minutes scrolling through social media and you’ll find ketamine described as everything from a so-called “miracle molecule” to “catalyst” for therapy. When traditional therapies have failed, the buzz surrounding ketamine can be especially tempting. But in my experience, that very sense of urgency can sometimes overshadow the need to watch for potential contraindications. You deserve relief, but you deserve safe relief.
At Field Trip Health, we anchor our protocols to the same oath I took on day one of medical school: first, do no harm. That oath informs our multi‑layered assessment process – initial screenings, physician consults, collaborative contacts with your specialists, and continuous in‑session monitoring. If we conclude that ketamine is not recommended in your case, it isn’t a judgment on your resilience. It’s a pause for safety.
How Ketamine Works and Why That Matters for Eligibility
Ketamine primarily blocks NMDA receptors, briefly increases glutamate, and kick‑starts a surge of brain‑derived neurotrophic factor (BDNF). It’s as if, for a short window, the brain eases its usual constraints and opens the floor to new neuronal interactions. This is terrific for disrupting depressive loops, but it can come with known physiological effects. Blood pressure can rise temporarily, heart rate can increase, and sensory perception can be altered from ordinary reality.
Having overseen hundreds of sessions, I can attest that while the dissociative state offers significant therapeutic benefit, it also carries some real risks. Individuals with cardiac or psychiatric vulnerabilities may not be able to withstand such an experience. That is why your medical history is not a side note – it is absolutely central to our conversation.
Who Should NOT Use Ketamine Therapy
To start, here are the circumstances when I would firmly advise holding off for now.
Unstable Cardiovascular Conditions
If you’re living with uncontrolled hypertension, unstable angina, or recent heart attack, ketamine’s pressor effect is unsafe. Meta-analyses and clinical studies report average increases in systolic blood pressure of about 12–16 mmHg and heart rate increases of around 4–10 bpm (beats per minute). As reported by NCBI Bookshelf, those changes can be concerning for patients at high risk, potentially even for arrhythmias or myocardial events. If you are a cardiac patient, until your cardiologist certifies stability – often reflected in consistent readings below 140/90 mmHg and a clear stress test, for example – KAP must wait.
Pregnancy and Breastfeeding
Pregnancy is a time when every medication undergoes intensified scrutiny, and ketamine is no exception. We have insufficient data on fetal neurodevelopmental impacts. According to NCBI Bookshelf, pregnant women are excluded from most ketamine studies. Ketamine metabolites in breastmilk are low in the hours after treatment and are deemed safe.
Acute Psychosis
When psychotic symptoms – hallucinations, delusions, or severe thought disorganization – are active, ketamine’s perceptual changes can amplify danger. Harvard Health notes that dissociation may worsen psychosis. We screen patient for history of acute psychosis and our nurses and therapists note any altered perceptions prior to treatment and will not engage in any treatment with ketamine in a patient with acute psychosis.
Severe Liver Disease
Because the liver is responsible for processing ketamine, conditions like cirrhosis or advanced hepatitis can hinder its breakdown, resulting in erratic blood concentrations and an increased risk of adverse effects. For stable cirrhotic patients without decompensation, ketamine may be considered safe, while in worsening cases it may not. In such cases, we defer and collaborate with your hepatologist for direction.
Dangerous Intracranial or Intraocular Pressure
In the past, doctors worried that ketamine might increase pressure inside the skull or eyes. Newer research has eased some of these fears, but we remain cautious. If you recently had a brain injury, have untreated hydrocephalus, or severe glaucoma, we hold off on ketamine until your specialists give the green light.
Medical Conditions to Consider Before Starting Ketamine Therapy
Now let’s examine scenarios that call for additional evaluation.
Renal or Mild Hepatic Impairment
If you have moderate kidney disease, your body gets rid of ketamine more slowly. Mild to moderate liver problems also slow how your body processes the drug. In these cases, I usually lower the dose, space out the sessions more, and order basic lab tests – ALT, AST, GGT, eGFR – to make sure treatment stays safe.
Uncontrolled Thyroid Disease
High thyroid levels often go hand in hand with certain heart rhythm issues. Because ketamine can speed up your heart rate, I coordinate with endocrinologists to stabilize thyroid levels before proceeding. Unmanaged thyroid disease increases the risk of rapid or irregular heartbeats during ketamine therapy.
Substance Use Disorders
While ketamine, when administered responsibly, can paradoxically reduce cravings for alcohol or opioids, the situation shifts when there is active substance abuse. This is especially true with stimulants or dissociative drugs, which amplify the risks. Harvard Health underscores the potential for ketamine use disorder, so I make it standard practice to require a verified sobriety period of 30 to 90 days before proceeding.
Epilepsy or Seizure Predisposition
Because ketamine can decrease seizure threshold, I always consult with a neurologist for anyone with a personal or family history of epilepsy. If you’ve remained seizure-free for a year on stable anticonvulsant therapy, we may proceed with rescue medications available as a precaution.
Psychiatric Exclusion Criteria for Ketamine Therapy
Safety isn’t just about your physical health; your mental landscape matters too.
Bipolar Mania or Rapid Cycling
Ketamine can boost mood so quickly, it feels like a super-charged antidepressant. This is great for bipolar depression, but we do not give it during manic or mixed episodes. For safety, we require you to be without a manic episode for several months, ideally one year or more, in addition to an anti manic therapy before we begin.
Active Suicidal Crisis Without Support
I know it seems counterintuitive because ketamine’s anti‑suicidality effect is well documented. But no one should leave a clinic and go home to a place that can’t support sudden mood swings. If you are in a serious crisis, staying in the hospital is still the safest choice. Once you’re safe, ketamine could become part of your plan to prevent future crises.
Severe Dissociative or Personality Disorders
Clients with dissociative identity disorder or borderline personality disorder sometimes experience destabilizing identity fragmentation under ketamine. That doesn’t automatically disqualify you, but we slow the pace, increase preparatory therapy, and consult your long‑term therapist before moving forward. The decision to proceed in these cases is a careful clinical assessment on a case by case basis.
Am I Ready for Ketamine Therapy? Key Psychological Considerations
Your mindset matters just as much as your diagnosis when it comes to results.
You might feel tempted to chase a “silver bullet” after years of frustration. At first, I believed more education about integration was enough. But I found out that motivation is the key factor. If you treat KAP as a one-time solution, you’re likely to miss the vital integration work – things like journaling, mindfulness, and lifestyle shifts – that make your progress last. Our data clearly shows that skipping integration leads to less lasting relief.
Having people around you who care makes a big difference. If your home life is full of conflict or people who don’t understand, it can make recovery harder. If support is missing, we may hold off on treatment while we help you find groups, online support, or family therapy.
The Grey Zone: Conditions That Can Evolve into Ketamine Therapy Eligibility
One of my favourite parts of clinical practice is seeing a “NO” transform into a “YES”. For instance, one of our clients arrived with blood pressure readings of 165/98 mmHg. We referred her back to primary care, optimized medication, and taught breathwork. Six weeks later she clocked a consistent 128/82 mmHg – and started KAP.
In the same way, new mothers may return after they’ve given birth. People with bipolar disorder become eligible if not in a manic episode and on lithium or another anti-manic agent. The main idea is that most reasons for not starting KAP are temporary, not permanent.
What Makes Someone a “Yes” for Ketamine Therapy?
By now you understand the red flags, but clarity also comes from seeing the green lights. A solid candidate comes to us medically stable – blood pressure controlled, no acute cardiac issues, and organ function within safe limits.
Psychiatrically, you’re dealing with depression, anxiety, PTSD, or chronic pain that’s genuinely treatment-resistant, yet you’re not in the grips of psychosis or mania. You carry realistic expectations, view integration as integral, and have at least one person in your corner for post‑session support.
Financially, you’ve budgeted for the full protocol. Most importantly, you’re curious, teachable, and willing to surrender – carefully – to an altered state of consciousness so you can explore buried emotions and form new neural pathways.
A Note on Hope, Safety, and Community
It’s easy to feel discouraged if you discover ketamine isn’t right for you today. I know that frustration deeply but there are alternatives that may be right for you such as rTMS.
At Field Trip Health we combine careful science with a caring, people-first approach, delivering treatments in Toronto, Montreal, Vancouver, Hamilton, and beyond. Our research collaborations include universities nationwide, fueling best practices. And yes, KAP can be transformative, but only when science, setting, and personal readiness align.
If this article nudges you toward greater self‑inquiry – questioning your cardiovascular health, reviewing your psychiatric timeline, or reevaluating your support network – then it has served its purpose. Whether you qualify now or must wait, hold on to the perspective that readiness is dynamic. Keep the conversation open with your care team, collect the data, and circle back. My colleagues and I stand ready to walk the path with you, guided by diligence, empathy, and the unwavering belief that safe healing is the only healing worth pursuing.
Frequently Asked Questions
To determine if you’re a good candidate for ketamine therapy, contact your healthcare provider, such as one of our consultants at Field Trip Health. They will schedule a consultation to review your medical history and medications. The medical team may contact your specialists to ensure safety and treatment readiness through a comprehensive, personalized assessment.
Ketamine is thought to be safe in patients with stable epilepsy controlled on medication. Patients must be well-controlled on medications and seizure-free for at least one year, or neurologist consultation ensuring clearance for treatment. Rescue medications should be available during treatment to manage potential side effects. Functional/ Psychogenic non epileptic seizures have been treated with ketamine by our team and would not be excluded from treatment.
Unlike traditional treatments, ketamine therapy works by blocking NMDA receptors, increasing glutamate, and triggering BDNF production. For treatment-resistant depression, ketamine creates rapid neurological changes, temporarily lifting brain barriers to form new connections. This provides faster relief for mental health conditions, with promising results often seen within hours rather than weeks.
Pregnant women are not candidates for ketamine therapy due to limited research on fetal neurodevelopmental impacts. Recent data suggests very low ketamine levels in breast milk 12 hours after ketamine exposure. We advise patients who are breastfeeding to abstain for 12- 24 hours after treatment and pump in between in order to supplement this period.
Patients with active psychosis, schizophrenia, schizoaffective disorder, bipolar mania, or severe dissociative disorders are typically not good candidates for ketamine therapy. In bipolar disorder, for patients with a depressive episode, we prefer patients to be free from a manic episode for one year and be on an anti manic therapy before considering ketamine treatment.
Social support is vital to the ketamine therapy process and overall well-being. Patients returning to negative environments often experience diminished therapeutic benefits. Before initiating treatment, clinics recommend ensuring an external support system as part of a comprehensive treatment plan to maximize ketamine therapy session outcomes.
Many private insurance plans cover the psychotherapy portion of ketamine-assisted therapy. At Field Trip Health, about 50% of the treatment cost may be eligible under psychotherapy coverage. Some clients have also received partial reimbursement for nursing services, such as Nurse Practitioner consultations. Patients should budget for a full treatment program and avoid cost-cutting measures that might compromise the treatment process, safety, or therapeutic outcomes. Oftentimes financing options are available for out-of-pocket portions.
Patients with uncontrolled hypertension, unstable heart disease, or recent cardiac events are not good candidates for ketamine therapy. Ketamine can raise systolic blood pressure by 15-20 mmHg and heart rate by up to 25 beats per minute in some cases. Eligibility requires stable blood pressure and pre treatment below 160/105 mmHg and cardiovascular clearance to ensure safety during treatment.
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).
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